A – Z guide to HIV Terminology

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  • Acquired Immune Deficiency Syndrome (AIDS)

    AIDS is clinical term that relates to having very low CD4 counts, often with substantial weight loss, and the occurrence of severe opportunistic infections that can lead to death if HIV antiretroviral treatment is not taken daily. Having HIV does not mean you have AIDS, but having AIDS means that your have uncontrolled HIV which has not been treated with daily HIV antiretroviral treatment, or immune (CD4) counts are very low (if treatment was delayed). Taking a combination of HIV antiretroviral (ARV) treatments daily, as prescribed by your doctor, prevents the progression to AIDS. AIDS conditions can be treated with other drugs, but the best treatment for preventing HIV from progressing to AIDS is HIV antiretroviral treatment and being linked to regular health-care monitoring. However, HIV ARV treatment does not cure or completely eradicate HIV from the body.

  • Acute

    Describes a stage or phase in a health condition that is new (i.e. the first or early phase of the condition) or has short-term symptoms which don’t last. Some acute conditions have the potential to develop into chronic (longer term) conditions, with new or different symptoms (than the acute phase) or persistent symptoms which don’t go away.

  • Acute and Primary HIV Infection

    Acute HIV infection is the first 2 to 4 weeks from initial infection until the body produces HIV immune antibodies that can be detected by an HIV antibody test. From the acute stage (first four weeks) into the early stage (first few months) and primary HIV infection stage (first 3-6 months) is when HIV is causing the most inflammation and doing damage to the body – when it is highly replicating making the viral load very high – also making it highly infectious to others. Early antiretroviral treatment during acute and primary HIV infection period stops immune system damage from HIV, and inhibits HIV from entering viral reservoirs (such as the brain and lymph system) where HIV antiretroviral treatment cannot otherwise reach well. The common signs of acute HIV infection are enlarged lymph glands (adenopathy), night sweats, diarrhoea, and flu-like symptoms – together these are known as ‘HIV seroconversion illness’. Some people don’t experience this illness, or only get a mild form of it, but they may still be infected with HIV and not know it, in the absence of symptoms and lack of regular testing to detect HIV early. Regular testing for HIV (and STIs) is encouraged for people at risk of HIV – at least every year, and four times a year if highly sexually active or not regularly using condoms.

  • Adenopathy

    The swelling or inflammation of glands, especially the lymph nodes of the neck, armpits, and groin. Adenopathy is sometimes an early sign of HIV infection, but it can be due to other infections – so testing for HIV and other infections is important to understand the cause of adenopathy.

  • Adherence

    The degree to which a person consistently takes their treatment(s), as prescribed by their doctor. HIV antiretroviral treatment is required to be taken daily, without regularly skipping or missing doses, at least 95% of the time. The old word for adherence is ‘compliance’ but that term is no longer used, as adherence to treatment is a recommended choice not an order to comply.

  • Advocacy/Advocate

    The word advocate comes from a Latin word meaning “to be called to stand beside”. Advocacy can have a range of different meanings depending on context, but in its broadest sense means supporting the interests of an individual or group with the aim of promoting and protecting their rights and welfare.

  • Anaemia

    A condition of reduced oxygen being transported in the blood to body tissues. It may be caused by a decrease in red blood cells or not enough iron in the diet. Anaemia may be a symptom of HIV-related conditions or a side effect of some HIV antiretroviral drugs. Symptoms include shortness of breath, fatigue and headache.

  • Anal Cancer – Also known as Anal Carcinoma

    Is a type of cancer which occurs in the anal canal. Symptoms of anal cancer include bloating and changes in bowel habits, a lump near the anus or anal canal, rectal bleeding, itching or discharge. Risk factors include having Human Papilloma Virus (HPV) infection, specifically types 16 and 18 (which are also linked to cervical cancer in women). These types are not associated with genital and anal warts (which are caused by other HPV types that do not cause anal cancer). Anal lesions are abnormal cells that differ in colour and texture to surrounding tissue, which may start as a small lump. Your doctor will determine if they are squamous cell carcinoma (SCC) cancer tumours – versus low or high grade (pre-cancerous) lesions. It’s important to ask your doctor about screening examinations. Early detection of anal cancer is important for treatment success, as treatment for anal cancer varies and can be drawn out and stressful. Forms of treatment include radiotherapy, chemotherapy, cryotherapy, and surgery. The presence of low or high grade lesions does not always progress to SCC anal cancer, but may suggest more regular examination is required. Anal cancer is uncommon, but on the increase among people living with HIV (PLHIV). The rates of anal cancer are also much higher in gay men than the general population. Tobacco smoking increases the risk of all cancers, including anal cancer. If you smoke, and are ready to consider quitting, speak to your doctor about treatment and support to assist you to quit smoking. Also see: www.qpp.org.au/living-hiv-staying-healthy/support-quit-smoking

  • Anoscopy

    A examination using a small instrument called an “anoscope” to examine the anal canal. This device is used by a doctor to look for haemorrhoids, anal fissures (small tears or splits in the anal wall) and anal lesions. Anal lesions may or may not progress to cancer. If cancerous lesions are suspected, follow on diagnosis and treatment will be recommended by your doctor. It is recommended that HIV-positive men in particular ask for an anal examination by their doctor at least annually.

  • Antibodies

    Proteins found in the blood and other body fluids, also known as immunoglobulin; they are produced by B cells in response to the presence of antigens. Antibodies function to protect the body from disease by binding to antigens, marking them for destruction by immune cells (such as macrophages), or coating the antigen neutralising its harmful effects. Because antibodies react to specific antigens they can be used to diagnose infections. Because HIV hides within immune cells (such as macrophages and T [CD4] cells), the immune system cannot work sufficiently to rid HIV from the body.

  • Antibody Positive

    The term used to describe a test result that has detected antibodies, to specific antigens, in the blood. A positive antibody result is represented by a plus sign (e.g. HIV+) confirming the infection.

  • Antigen

    A foreign substance or infection, which stimulates an immune antibody response. Antigens have the potential to cause disease, unless they are inactivated antigens as used in vaccines to elicit an immune protective response. Each antigen is characterised by its specific individual structure that identifies it as being foreign to the body. Antigens are present on infectious viruses, bacteria, fungi, protozoa, and toxins. They are found either circulating freely in the blood or are displayed by virus-infected cells.

  • Antiretroviral Therapy (ARV Therapy or ART)

    Also known as Combination Antiretroviral Therapy (cART) , Highly Active Antiretroviral Therapy (HAART), or HIV antiretroviral (ARV) treatment.

    Highly Specialised Drugs (HSD) designed to act specifically against HIV replication – usually taken as a combination using at least 3 different drugs. The aim of this therapy is to supress the replication of HIV by inhibiting the function of HIV enzymes. HIV (ARV) therapy does not cure or completely eradicate HIV from the body. There are currently five classes (types) of HIV antiretroviral available: nucleoside reverse transcriptase inhibitors (NRTIs); non-nucleoside reverse transcriptase inhibitors (NNRTIs); protease inhibitors (PIs); integrase strand transfer inhibitors (INSTIs); and entry inhibitors (EIs). The ‘class’ of drug describes which part of the HIV replication lifecycle that class inhibits. The number of drugs in each class provides options for choosing treatment combinations. Lists of current HIV antiretroviral treatments and drug classes are widely available on the internet, or ask your clinic or community organisation for a current list.

    The Australian HIV treatment guidelines suggest all people with HIV should consider taking HIV treatment as close to diagnosis as possible (regardless of CD4 count), pending patient needs, circumstances and preparedness or willingness to commence treatment. Treatment Guidelines change often (based on new clinical research evidence). For current treatment guidelines visit: www.arv.ashm.org.au

  • Antiretroviral Treatment Naive

    Someone who has never started HIV antiretroviral treatment (ART). People who have already started treatment, or previously were on treatment (but not currently), are known as “ART-experienced” because they have had ‘experience’ with taking HIV treatment already.

  • Asymptomatic

    A disease or infection, or stage in a disease or infection, which has no obvious symptoms. Whilst most diseases and infections do have symptoms, some may not show symptoms all the time, or at all; but tests provided by your doctor can determine if the disease or infection is present. Some stages of HIV infection can be asymptomatic, especially in the early infection stages, after an initial seroconversion illness. Some sexually transmitted infections (STIs) may not show symptoms – this is why getting regular HIV and STI tests is important, especially if you have multiple sex partners or don’t use condoms consistently.

  • Atherosclerosis

    Thickening of the inner wall of arteries (major blood vessels), which narrows the space for blood to flow within them causing blockages in blood flow. If coronary (heart) arteries are involved this may lead to angina (chest pain) or to a heart attack. If the arteries to the brain are involved a stroke can occur.


  • B-cells

    Immune system cells, also known as B lymphocytes that function to protect the body from disease. B-cells are the front-line immune cells which respond to the presence of specific antigens that are circulating freely in the blood. Once exposed to an antigen B-cells transform into plasma cells that multiply rapidly and manufacture large numbers of antigen-specific antibodies.

  • Biopsy

    The removal of a small sample of bodily tissue for microscopic examination. The purpose of this examination is to test for the presence of cancer or other diseases and infections. A biopsy may require a local or general anaesthetic.

  • Blip

    A temporary, small but detectable increase (of about 100 or 200 copies) in the amount of HIV in the blood (viral load) that occurs after antiretroviral therapy (ART) has effectively suppressed the virus to an undetectable level (below 40 copies). Occasional blips are not considered a sign of treatment failure.

  • Blood Brain Barrier

    The protective barrier surrounding the brain that restricts the passage of certain substances, including some drugs, from the blood vessels to the brain tissue.

  • Body Fluids

    The fluids that are naturally produced by the body. These fluids include tears, saliva, mucous, urine, blood, semen, vaginal secretions and breast milk.

  • Bone Marrow

    The soft material located in the cavities of bones. Bone marrow is the site of production of erythrocytes (red blood cells) leucocytes (white blood cells) and platelets (clotting blood cells).

  • Candidiasis

    An infection caused by overgrowth of the fungus ‘Candida albicans’. The fungus exists naturally in the mouth, throat, vagina, digestive tract and folds of the skin including the penis. Normally candida does not cause disease, although it is a sign of lowered immunity and is a common opportunistic infection in untreated advanced HIV disease. Candidiasis develops if something disrupts the balance of fungus in the body and an overgrowth develops, commonly called thrush. Symptoms vary depending on the site affected. Oral candidiasis – oral/mouth thrush – appears as white patches on the tongue, gums, and inner cheeks, which may be painful. Vaginal candidiasis causes a white discharge and itch. It is a common problem for all women but the prevalence is higher in women who are HIV-positive. HIV-positive men do not seem to have a higher prevalence of penile candidiasis, and it is less common in men overall, although it can be passed on through sexual contact. Candida of the oesophagus (throat) is rarely seen if the immune system is functioning well, and is more likely to develop if the CD4 cell count is below 200. Oesophageal (throat) candidiasis can be painful and may lead to difficulty swallowing. Treatment depends on the site affected but candidiasis responds well to antifungal drugs, although it can also be difficult to treat in severe cases and may often reoccur without any apparent predisposing risk factors.

  • Cardiomyopathy

    An inflammation or enlargement of the heart muscle. Cardiomyopathy weakens the heart muscle, making it difficult for the heart to pump blood to the rest of the body. HIV infection or use of some antiretroviral (ARV) drugs may cause cardiomyopathy.

  • Cardiovascular (heart) Disease

    Relating to or involving the heart (cardio) and blood vessels (vascular). HIV infection and the use of some antiretroviral (ARV) drugs may increase the risk of cardiovascular (heart) disease. Cardiovascular disease can cause stroke (interruption of blood supply to the brain) and myocardial infarction (heart attack where the heart stops beating). Stroke and Heart Attack can be fatal or non-fatal. Early signs may be angina (stabbing pains or deep aching in the upper chest). If you experience these signs, including shortness of breath, cold sweats or sudden changes in body function such as numbness, movement loss, vision loss, and severe headache, call an ambulance on by dialling triple zero 0-0-0. Your HIV doctor of General Practitioner (GP) will monitor your cardiovascular risk profile generally from routine blood tests (such as cholesterol, and other measurements). Smoking tobacco substantially increases the risk of cardiovascular disease (and cancer) – if you smoke, and are ready to consider quitting, speak to your doctor about treatment and support to assist you to quit smoking.  Also see: www.qpp.org.au/living-hiv-staying-healthy/support-quit-smoking

  • CD4 : CD8 Ratio

    A test that compares the number of CD4 cells to the number of CD8 cells. It is used to help diagnose primary (recent, early) HIV infection and guide decisions about treatment. Normally the CD4 cell count is higher than the CD8 cell count; normal values are approximately 30-60% CD4 and 10-30% CD8 depending on age. In early HIV infection the CD4 cell count decreases and the CD8 cell count increases.

    The CD4:CD8 ratio is rarely less than 1.0 in HIV negative individuals, but may drop as low as 0.1 in patients with recent HIV infection or very advanced disease. There is almost always substantial recovery of this ratio, even without antiretroviral therapy, during the 2-3rd month of HIV infection, which then persists for some time. The CD4:CD8 ratio will generally gradually decline over years of HIV infection in the absence of HIV antiretroviral therapy (ART). When HIV ART is started fairly early after infection, this ratio may again rise to above 1.0 – a recovery rarely seen in patients with more advanced HIV infection who start on treatment.

  • CD4 Cell count

    The CD4 count is a measurement of how many functional (HIV-uninfected) CD4 T-cells are circulating in the blood. The lower the CD4 count, the weaker the immune system. As HIV mainly targets these cells their number declines as the infection progresses (if HIV ARV treatment is not taken). The effect of HIV on the immune system is assessed by monitoring the CD4 cell count over time. The CD4 cell count is used to anticipate the onset of opportunistic infections and is used to decide when to start treatment.

    The rate of CD4 decline is proportionate to the HIV viral load. In other words, as viral load falls (with effective HIV ARV treatment) gradually CD4 count returns to baseline (i.e. increases to about the same as what it was at the time of infection). HIV Treatment Guidelines now recommend early HIV (ARV) treatment regardless of CD4 count loss. HIV (ARV) treatment keeps the virus levels low (see viral load), slowing or stopping the invasion of CD4 cells, then the CD4 count numbers can grow and survive again, making the immune system protected from further HIV replication in the body.

    The CD4 count tends to be lower in the morning and higher in the evening (natural fluctuation).

    The CD4 count is measured by a simple blood test and is reported as the number of CD4 cells per cubic millilitre of blood. HIV-negative people typically have CD4 counts between 600 and 1200 (range). HIV-positive people have counts that are typically less than 500 (but can be higher when taking effective ARV treatment). HIV-positive people with AIDS can have 200 CD4 cells or fewer (although AIDS-related conditions can also occur at higher CD4 counts than this as well). The CD4 count provides a general guide on level of robustness of the immune system to keep AIDS opportunistic infections away.

  • CD4 Cells / CD4 T Cells

    A subset of white blood cells (leucocytes) called ‘T (helper) lymphocyte’ cells that have a protein molecule called ‘CD4’ on the surface of these cells. CD4 ‘helper’ cells initiate the body’s reaction to infections by regulating the immune response by sending out chemical signals (release of cytokines) that interact with and stimulate the growth and activity of other immune system cells, such as B cells and CD8 cells. CD4 cells are like the ‘commanders’ of the immune system alerting the entire immune system (the ‘army’ of other cells) to an ‘invader’. CD4 is also present on the surface of other immune system cells called macrophages and dendritic cells. HIV has an affinity with (is attracted to) to the CD4 cell surface, and binds with CD4 allowing HIV to attach then enter and infect the human CD4 T cells.  This inactivates the function of the CD4 cells to ‘command’ the immune system, since CD4 T cells are the primary target of HIV. HIV destroys the immune system by invading and attacking CD4 cells, then hiding in them (unable to seen by other immune system cells) until it re-emerges as a new virus particle from within the human cell (killing that cell in the process), then the new virus particle goes on to infect other CD4 T cells. The gradual loss of CD4 T cells then impairs the function of the immune system. HIV antiretroviral (ARV) treatment stops the destruction of CD4 T cells by slowing HIV replication.

  • CD4 Percentage

    Not all T-lymphocytes express CD4 on their surface, so the total lymphocyte (white blood cell) count is an important measurement your doctor will monitor was well in your routine blood tests. The CD4 percentage takes into consideration the total lymphocyte count when assessing immune system health. The CD4 percentage may be an additional (or secondary) clinical marker (indicator) to help guide treatment decisions. Generally a CD4 percentage below 20% suggests declining immune system health, so it is best to have a percentage results above this. Below 15% can be considered an increased risk of HIV disease progression and opportunistic infections.

  • CD8 Cells

    A subset of white blood cells (leucocytes) called “T (cytotoxic – ‘killer’) lymphocyte” cells that have a protein molecule called “CD8” on the surface of these cells. CD8 functions to detect virus-infected cells (and cancer cells) and ‘kill’ cells that are infected, rather than killing the virus directly, and so they prevent viral replication. CD8 cells are usually activated by CD4 cells, but CD8 cells are unable to kill CD4 cells because HIV ‘hides’ in CD4 cells (see CD4 cells). As HIV infection progresses (without HIV ARV treatment) CD8 cell function declines due to decrease in the number of CD4 cells. However, in primary (early) HIV infection, the CD8 cell count can increase to twice the normal range. This is a sign that the body is responding to the presence of HIV (an invading pathogen), although this immune inflammatory response does not last in absence of HIV ARV treatment – which supresses HIV virus from ongoing replication and preserves or restores the immune system.

  • Central Nervous System (CNS)

    The part of the nervous system that consists of the brain, spinal cord and the meninges (the membrane that covers the brain and spinal cord).

  • Cervical Cancer

    A cancer of the lower end of the womb (cervix) in women. Cervical cancer begins as an abnormal change to the cells called dysplasia. Most abnormal cell changes are harmless but some may progress to cancer. Early detection and screening through regular PAP smears is the key to better treatment outcomes, before cancer develops.

    The main cause of cervical cancer is from infection with Human Papilloma Virus (HPV). Tobacco smoking increases the risk of all cancers, including cervical cancer. Being HIV-positive may increase the risk of developing cervical cancer.

    Early cervical cancer is asymptomatic. Signs of progressive disease include abnormal bleeding and vaginal discharge. Cervical cancer is treated with surgery, cryotherapy and chemotherapy and is preventable with the HPV vaccine (Gardasil) and regular Pap smears (recommended annually for women with HIV).

    Smoking tobacco substantially increases the risk of all cancers. If you smoke, and are ready to consider quitting, speak to your doctor about treatment and support to assist you to quit smoking.  Also see: www.qpp.org.au/living-hiv-staying-healthy/support-quit-smoking

  • Chlamydia

    Chlamydia is a bacteria – Chlamydia trachomatis – that commonly affects the urethra (urinary tract – males and females) and cervix (in females). It is the most prevalent (common) STI, and if left untreated it can cause infertility in men and women.

    Chlamydia can be passed on through oral sex (with males or females), causing infection in the throat. It can also be passed on through anal and vaginal sex (in the absence of condoms), causing infection in the genitals or anus. Infection can also be transferred from the fingers (from touching the genitals) to other parts of the body (e.g. eyes).  Chlamydia is NOT transmitted through casual contact, nor through kissing, handshaking, sharing towels, cups etc.

    Condoms and dams are the best form of prevention, although they may not prevent all infection risks. It is important to avoid sex until the infection clears up (through treatment – see below) and inform sexual partners (see STI Prevention – Contact Tracing) to prevent transmission and reinfection. You can get chlamydia again even if you had it before.

    Regular testing is recommended, every 3 months if you are sexually active and at risk, because most people do not develop any symptoms of Chlamydia. A urine test or swab of the penis or vagina/cervix (or anal swab) is undertaken with your doctor.

    If symptoms do occur (usually within 2-14 days) a clear or cloudy discharge (which can be smelly) can occur from the penis or vagina, and a burning pain when passing urine. Infection in the anus (known as ‘rectal chlamydia’) can cause a similar discharge from the anus.  For women, it may also incur pain during sex, cramps in the lower abdomen, and bleeding between periods (menstrual cycle).  Symptoms of Chlamydia can be similar to gonorrhoea.

    Treatment for Chlamydia can be effective and simple with a single dose of antibiotic, but longer treatment can sometimes be required with symptomatic illness (until symptoms clear up). Without treatment the infection can spread causing testes pain (in men) and contribute to pelvic inflammatory disease (PID) in women, and lead to bladder inflammation (cystitis) and infertility.  It can also be passed on a new born baby during childbirth, and during pregnancy may cause premature birth, miscarriage and ectopic pregnancy (outside the womb).

    About Chlamydia:




  • Cholesterol

    Cholesterol is a natural substance produced in the liver. A certain amount of cholesterol is required to circulate in the bloodstream for many normal body functions (such as the nervous system, blood vessels, heart function, and hormonal production). However it should not be excessively high, aiming to keep the total amount of cholesterol below < 4.0. The total cholesterol is measured by adding the HDL Cholesterol, plus LDL Cholesterol, plus Triglyceride levels.

    Factors affecting cholesterol levels can be many, such as your genetic makeup, your weight, your level of physical activity and the types of food that you eat. If you have been diagnosed as having high cholesterol (hypercholesterolaemia), you should aim to reduce your cholesterol levels by eating a low-fat diet (especially avoiding saturated fats from animal based sources and fried foods) and start a moderate exercise program (based upon your age and other health conditions that may affect the type of exercise you can do). Medications may also be required to reduce your cholesterol to acceptable levels, and thus lower your cardiovascular and diabetes risk (both of which are linked to blood fat disorders). Seek information and guidance from your doctor and other healthcare provider about an exercise and diet program specific to your individual health and personal needs.

  • Chronic

    The term used to describe a disease or condition that extends over a long period of time, and may progress slowly or show little change in symptoms. Some chronic conditions may not have a cure available, but are able to be effectively and safely managed with suppressive and therapeutic treatment. Use of effective HIV antiretroviral treatment, now classifies HIV as a “chronic manageable condition”, like a number of chronic conditions (such as diabetes); but this does not mean that HIV is no longer a threat to health since HIV ARV treatment-does not cure HIV, but instead makes it more manageable, lowering the risk of serious health outcomes through taking effective HIV ARV treatment daily.

  • Cirrhosis

    A liver condition that is caused by persistent damage to liver cells from infections like viral hepatitis or from excessive daily alcohol consumption. Cirrhosis develops slowly from the build-up of scar tissue (hardening of the liver) which prevents adequate blood supply from flowing through the liver so it can no longer effectively perform its function to filter (clean waste material from) the blood. There is no cure for cirrhosis, but treatment is available to prevent further damage.

  • Clinical Trial / Study

    The terms ‘trial’ and ‘study’ are interchangeable. A clinical study is performed to test the safety and effectiveness of a new experimental drug or combination of drugs or therapy. Ethical studies always have a document called the “study protocol” which describes the characteristics and number of participants being sought for the trial; the expected duration of the trial; the experimental drugs or therapy involved (under trial); the dose levels being studied; and the desired and expected (hypothesised) outcomes and effects of the study. A study protocol also includes a list of events under which the trail will be suspended or stopped. Anyone participating in a study has a right to be advised of the protocol and their rights in participating before entering the trial. Participants of any study can also withdraw at any time, which is one of the rights of participating in a study.

  • Cluster of Differentiation (CD)

    “CD” refers to a class of molecules found on the surface of leucocytes (white blood cells). They are receptors that receive information enabling these cells to interact with each other. There are many types of CD receptors, each having a distinct function. They are classified with numbers that identify their function and distinguish different cell types. A cell that bears a particular type of CD is represented with a plus sign (e.g. CD8+ cell), however often the plus sign is dropped. The most commonly known and discussed CD receptor in HIV infection is CD4.

  • Co-infection

    Infections that are present at the same time as HIV infection. They may be acquired before, after or at the same time as HIV. Co-infections may contribute to the progression of HIV infection or can be risk factors for HIV transmission. Some co-infections complicate the treatment of HIV and may become more difficult to treat over time and symptoms may increase in severity. Hepatitis B and C are common HIV co-infections. Other sexually transmissible infections (STIs) can also occur as co-infections. Many co-infections can be effectively treated and cured, but some cannot (for example herpes or HPV infection). Many co-infections can be prevented by reducing risks associated with acquiring them (such as hepatitis C) and some are vaccine preventable (such as hepatitis A and B).

  • Cognitive Impairment Also known as Cognitive Decline or Cognitive Disorder

    Having difficulty thinking, concentrating, remembering, or undertaking complex tasks. Some people with HIV may develop cognitive impairment from HIV entering the brain and nervous system (in this case the condition is called “HIV-associated Neurocognitive Disorder – HAND”). Mild symptoms can occur (known as “Mild Neurocognitive Disorder – MND”), which do not necessarily affect daily functioning, such as a failure to recall certain words, or mild memory loss, but these should be discussed with your doctor if they become problematic to you. Depression is also linked to cognitive impairment. There may be other reasons for cognitive impairment, like normal ageing, so it is important to work out the causes and risk factors with your doctor. Functional cognitive capacity is NOT related to a person’s intelligence (IQ).

  • Combination Therapy

    The use of two of more HIV antiretroviral drugs, rather than a single drug (monotherapy) to treat HIV. Commonly three (3) drug combinations are used in HIV ARV therapy. Combination therapy is more effective in decreasing HIV viral load and reduces the development of drug resistance.

  • Communicable Disease

    An infectious disease, such as HIV and other STIs, that can be passed on to others. The route (method) of transmission varies among different types of communicable diseases – not all communicable diseases are passed on through unsafe sex. For example, HPV can be acquired by skin contact alone, and tuberculosis (TB) can be acquired from respirable air (i.e. breathing in the breath of someone with active TB). Some communicable diseases may be acquired by more than one route – for example HCV is commonly acquired by sharing drug injecting equipment and needles, but it can also be acquired (more rarely) by unsafe sex – particularly where there is blood-to-blood exposure between individuals.

  • Complementary therapies Also known as Natural Therapies or Alternative therapies

    Any treatment or therapy that does not fall within the realm of conventional medicine. Often it is based on historical or cultural traditions, and may not have scientific evidence, nor have been researched in a HIV context. There is no alternative therapy which directly or primarily treats HIV like conventional medicine HIV ARV treatments do. ‘Alternative’ therapy should not be considered as an ‘alternative’ or replacement for HIV ARV treatments. However, where good scientific evidence exists, some alternative therapies may be considered ‘complementary’ to HIV medicine, so long as the complementary therapy does not interact with HIV ARV treatment and is without added side effects. This may include dietary and micronutrient supplements. There is some HIV specific research which has demonstrated added health benefits for HIV using certain micronutrients (such as B group vitamins) which are considered health supportive generally. Other alternative or complementary therapies include acupuncture, herbal medicine and practices like yoga or meditation. The benefits or risks of each field of alternative therapy need to be closely examined for such. Be sure to discuss any alternative or complementary therapies you take with your doctor or primary health care provider.

  • Compliance

    See Adherence

  • Concordant

    See Sero-concordant

  • Condom

    A contraceptive and safe sex device used during sexual intercourse (anal and vaginal) to reduce the likelihood of pregnancy and to prevent the transmission of sexually transmitted infections (STIs), including HIV. The male condom is a thin rubber cover that fits over a man’s erect penis. The internal condom is a polyurethane pouch that fits inside the vagina. Water-based lubricant is recommended to be used with condoms, to prevent the condom from breaking.

  • Contact Tracing

    Contact tracing (or partner notification) is where any sexual partners you have had since you may have become infected with an STI should also go for sexual health test check, as they may also need to be treated.

    Not all STIs need contact tracing (such as herpes or genital warts), but the more serious and health impacting conditions do (such as chlamydia, gonorrhoea, syphilis, hepatitis, etc.).

    Your diagnosing doctor can discuss partner notification needs with you.

    If contact tracing is recommended, there are ways to let your partners know they may have been exposed to an STIs without disclosing your identity (i.e. anonymously).

    Click here to notify your partners now:

    www.letthemknow.org.au/ or

    http://bettertoknow.org.au/notify or


  • Criminalisation Also Referred to as The Criminalisation of HIV

    Term used to describe the use of criminal law to regulate HIV transmission and disclosure. Criminal offences in Queensland are governed by the Queensland Criminal Code Act 1899. In Queensland, it is an offence to transmit HIV with intent (Section 317[b]) or to do unlawful grievous bodily harm to another (s 320).

  • Cross Resistance

    Cross resistance develops when a virus mutates (changes) so that is it is resistant to more than one drug. This can occur when two drugs of the same class (type) have very similar chemical compositions, whereby resistance to one of those drugs may also mean resistance to the other drug, due to their similarity. Your doctor will advise if drug resistance is present, by conducting a resistance test, but good adherence (taking your HIV ARV treatments daily as prescribed) prevents drug resistance occurring mostly. If resistance is high (and your treatments stop working effectively), your doctor will advise about other treatment options – sometimes a different drug class (type) may need to be used if there is cross resistance present.

  • Cytokines

    A group of proteins produced by the cells of the immune system that act as chemical messengers between these cells. Cytokines include interleukin-2 (IL-2) which stimulates the growth and activation of T (lymphocytes) cells, and interleukin-4 (IL-4) which promotes antibody production. The production of certain cytokines declines as HIV infection progresses (if not taking HIV ARV treatment), inhibiting immune system function

  • Dams (Dental Dam)

    A thin, rectangular sheet of latex that is used as a barrier to prevent the transmission of sexually transmitted infections (STIs), including HIV. The dam is placed over the anus or vagina prior to oral sex or rimming to prevent body fluids being shared. Water-based lubricant is recommended to be used with dams, to prevent breakage. Dams should not be shared between sex partners – a new dam should be used for each sex partner.

  • Deoxyribonucleic Acid (DNA)

    DNA is the genetic code (chromosome molecule) of all living organisms that allow it to replicate and grow. DNA is composed of genetic and heredity codes. Under the microscope it looks like a double-strand helix pattern – where two (2) RNA (single strand) molecules wrap around each other. HIV is a single strand RNA virus that ‘steals’ another single strand from the human host cell DNA, to form its own DNA so it can produce more virus particles which continue to infect other cells in the body. HIV antiretroviral treatment blocks this process of HIV assembly against invading the body’s human host cell DNA.

  • Diagnosis

    The process of determining the cause and type of disease or infection. A diagnosis is made based on signs and symptoms, physical examinations and medical test results conducted by your doctor.

  • Discordant

    -see sero-discordant.

  • Discrimination

    Discrimination is where a person with a certain characteristic is treated or proposed to be treated less favourably than a person without that characteristic in similar circumstances. Discriminating against someone because of their HIV status can be unlawful in Australia. The Commonwealth and State Government have enacted anti-discrimination laws to help regulate unlawful discrimination.

  • Dissemination

    The spread of a condition, from its point of origin, through the body tissues or organs.

  • Drug Interaction

    A change in a drug’s effect on the body when taken together with other drugs, supplements or certain foods/herbs. A drug interaction may cause the drug to become less effective, cause adverse (side) effects or increase the action of the drug more than is needed. Potential drug interactions are considered by your doctor when selecting your HIV antiretroviral (ARV) treatment regimen, as well as with other medications you may be taking or needing to take. Illicit drugs can also interact with prescribed drugs.

  • Drug resistance

    A decrease in the body’s sensitivity to (and effectiveness of) a drug. Resistance is the result of mutation (change in the genetic code of the virus). Resistance to HIV antiretroviral drugs usually arises due to lack of proper adherence (i.e. skipping and missing doses). If resistance emerges the drug cannot as effectively target HIV enzymes (proteins that regulate the replication of HIV) that they are designed to. A mutation that alters the structure of a viral enzyme will decrease the virus’s sensitivity to the drug. When this occurs the drug will be less able to continue to supress the replication of the mutated virus, and the virus will still be able to replicate, leading to treatment failure and increased HIV viral load. Drug resistance can also develop in other viruses, bacteria, fungi and protozoa.

  • Efficacy

    A measure of the ability of a drug to achieve the desired effect at a specific dose level. Efficacy is usually measured in percent (%). Phase II trials gauge efficacy (and safety) of a new treatment, and Phase III trials confirm it.

  • Elite Controllers

    A very small percentage (1%) of people living with HIV (PLHIV) who are able to maintain a very low or undetectable viral load for many years (sometimes decades) without taking HIV antiretroviral (ARV) treatment. Antiretroviral therapy (ART) may be theoretically beneficial for elite controllers (to prevent long term inflammation of HIV at low levels of viral replication). It is thought that elite controllers may lack a surface receptor on T cells that highly, but not completely, prevents HIV from entering and infecting these cells. The other 99% (majority) of PLHIV need to take HIV ARV treatment to control HIV.

  • Encephalitis

    An inflammation of the brain caused by viral, bacterial or protozoal infections. The inflammation is the body’s reaction to infection. Swelling occurs that may lead to destruction of tissue. Toxoplasmosis is the most common cause of encephalitis in HIV infection. Conditions like toxoplasmosis rarely occur now, due to effective HIV antiretroviral treatments.

  • Endoscopy

    An examination using a small medical instrument called an endoscope (tube and camera) that permits direct visualisation to see inside internal organs, to check their condition and look for any signs of disease. Endoscopes are inserted either directly into the digestive tract (gastroscopy); throat (oesophagoscopy); respiratory tract wind pipe and lungs (bronchoscopy); urinary tract/bladder (cystoscopy); colon/bowel/anus (colonoscopy, anoscopy); or through very small incisions in the skin to look at other body parts. Endoscopes are also used to help perform surgery and to remove tiny amounts of tissue (biopsies) from internal organs for further medical examination.

  • Enzyme

    A substance that induces chemical reactions in the body. Enzymes work by either binding small molecules together to create a larger molecule, or dividing a large molecule into small molecules.

  • Enzyme-Linked Immunosorbent Assay (ELISA Test)

    A laboratory technique for detecting antigens or antibodies. ELISA is commonly used to screen for HIV antibodies. Since false positives can occur; positive results are confirmed with a western blot test.

  • Erythrocytes

    The term for red blood cells. The major function of erythrocytes is to transport oxygen to the tissues and remove carbon dioxide.

  • False Negative

    A test result that incorrectly indicates that the condition being tested for is not present when, in fact, the condition is actually present. For example, a false negative HIV test indicates a person does not have HIV when, in fact, the person is infected with HIV. False negative non-reactive tests are not common in standard HIV clinical testing. In some rapid tests if you have taken the test too close to when the infection has occurred that test result might not show up HIV-antibodies as your body hasn’t had time to develop them. It can take up to 30 days before your immune system has reacted to the presence of HIV and therefore developed antibodies. This is called ‘the window period’. Other tests can be run if a test is suspected to be false-negative (for example the p24 antigen test).

  • False Positive

    A positive test result that incorrectly indicates that the condition being tested for is present when, in fact, the condition is actually not present. For example, a false positive HIV test indicates a person has HIV when, in fact, the person is not infected with HIV. False positive reactive tests are not common in standard HIV clinical testing. False positives can sometimes occur due to other infections that might be present at the time of being tested. Other tests can be run if a test is suspected to be false-positive, and all HIV-positive results are sent for confirmatory testing using other methods regardless.

  • Free Radicals

    A by-product of the body’s cells natural respiration – i.e. chemical reactions within body cells which exchange oxygen for energy. Highly reactive free radical substances are then formed which circulate around the body, and there is a theory that these build up as we age and that they are involved in the ageing process. Anti-oxidant free radical scavengers are sometimes useful to ‘mop up’ (eliminate) free radial accumulation in the body. Some specific vitamins can assist to slow down or mop up free radicals in the body, but they will not stop the ageing process. Avoiding cigarettes, pollution, limiting alcohol consumption and fresh food diets are important lifestyle factors which help to limit free radical accumulation and damage.

  • Full Blood Count (FBC)

    A simple blood test that looks at parts of your blood including your red blood cells (RBC), white blood cells (WBC), platelets, haemoglobin and haematocrit. Red blood cells carry oxygen and nutrients through your body; white blood cells are immune cells (B cells and T cells); haemoglobin and haematocrit are part of red blood cells, that, respectively, exchange iron for energy to cells and the amount (number) of RBC’s. Your doctor will tell you when these measurements are good or need further checking or medical treatment and management.

  • Gastroenteritis

    An inflammation of the lining of the stomach and intestines. It is frequently due to infectious agents (e.g. campylobacter and salmonella), but stress and food allergies can be responsible. In some cases CMV or HIV itself may be responsible. Symptoms include diarrhoea, vomiting, headache, nausea and stomach cramps. Treatment depends on the cause but generally includes anti-diarrhoea medication and measures to prevent dehydration and malnutrition.

  • Gene Therapy

    Treatment based on the alteration of human genes. The aim of gene therapy is to either render cells resistant to infection or renew immune system function. Studies conducted on gene therapies for the treatment of HIV are currently experimental but are showing some promising results.

  • Generic

    A term related to medications. The term is used in two non-identical/different contexts:

    1. To identify the active ingredient in any trade-name/branded drug. For example raltegravir is the generic name for Isentress (brand name). Usually your doctor and health-care provider will use the generic name when referring to an HIV ARV drug, unless it is a combination single tablet drug, for example “Atripla” (which contains 3 drugs with the generic names: tenofovir, emtricitabine, and efavirenz).
    2.  The generic name is different from a generic version of a medicine. In order for there to be a generic version of a medicine, the original medicine must have gone off-patent (licence), and another company (besides the original manufacturer) then can make the product. Patients then have the right to select a generic version of drug (which is often much cheaper) or the trade-name/branded version (from the original manufacturer). The two different versions are said to be ‘bioequivalent’, meaning they work as well as each other (efficacy) and have the same or similar safe profile (side effects). Generic versions of some (but not all) HIV drugs are available.
  • Genital Warts

    Also known as: Condyloma Acuminatum, Venereal Warts

    A sexually transmitted infection caused by the human papillomavirus (HPV). Genital warts appear as raised pink or flesh-coloured bumps on the surface of the vagina, cervix, tip of the penis or anus.

  • Gonorrhoea

    Gonorrhoea is caused by a bacterium – Neisseria gonorrhoeae – that can develop in the urethra (urinary tract), anus, throat, cervix or uterus. It can cause painful urination (stinging or burning sensation) and white-or-yellowish discharge from the genitals or anus. Sometimes infection can occur in the eye causing conjunctivitis.

    If gonorrhoea is left untreated it can cause infertility in men and women. It can also increase the risk of HIV transmission.

    Up to 80% of women and 10-15% men may not develop symptoms, so regular testing is important (if sexually active) as gonorrhoea is highly contagious even without symptoms. Symptoms of gonorrhoea can be similar to chlamydia.

    Gonorrhoea is spread by contact with semen and vaginal fluids during anal and vaginal sex without a condom. Therefore, condoms offer the greatest protection against gonorrhoea. Oral sex can be a risk, where infection can occur in the throat. Other risks include sharing sex toys (that have not been thoroughly washed in warm soapy water), sexual foreplay where the infection can be transferred from the fingers (from touching the genitals) to other parts of the body (e.g. eyes). You cannot catch gonorrhoea from simple kissing, shaking hands, hugging, sharing towels, cups or utensils, or from a toilet seat.

    Testing for gonorrhoea involves a urine test or a swab sample (taken from the penis, anus, vagina/cervix, or throat). Regular testing is recommended, every 3 months if you are sexually active and at risk.

    Treatment for gonorrhoea involves a single antibiotic injection, and either a single or multiple doses of antibiotic tablets, depending on symptoms. Antibiotic resistance to treatment can occur, so dual antibiotic treatment is recommended.

    It is important to avoid sex until the infection clears up (through treatment) and inform sexual partners (see STI Prevention – Contact Tracing) to prevent transmission and reinfection. You can get gonorrhoea again even if you had it before.

    Note: clear or white discharge in the urinary tract (from the penis or vagina) can also be caused by other non-specific organisms (not gonorrhoea or chlamydia).  This is called Non-Specific Urethritis (NSU) which can also have serious health impacts if not treated, and is sexually contagious in the same way as gonorrhoea or chlamydia is.  Your doctor will work out the cause of any discharge and provide the correct course of antibiotic treatment.

    About gonorrhoea:




    About NSU:




  • Haemophilia

    A hereditary disorder of the blood in which there is a deficiency of clotting factors. People with haemophilia have a tendency to bleed excessively and may need blood transfusions. Prior to 1990, before HIV was screened from the Australian Blood Bank supply, some people with haemophilia requiring blood transfusion acquired HIV this way.

  • Half-Life

    The time it takes a drug to lose half its original concentration or activity after being introduced into the body. Drug half-life is considered when determining drug dosing periods/frequencies.

  • Hepatitis

    An inflammation of the liver commonly caused by viral infections (such as Hepatitis A, B or C), but may also be due to substances which are toxic to the liver or a side-effect of drug therapy. Vaccines are available to prevent Hepatitis A and Hepatitis B, but there is no vaccine for Hepatitis C.

  • Hepatitis A Virus (HAV)

    Hepatitis A can be passed on through oral-faecal (poo) pathway such as through anal rimming during sex, or from hand to mouth such as through contaminated food or water. Hand washing with warm water and soap after going to the toilet and during food handling and preparation will prevent non-sexual pathways of transmission.  Dental dams or other barrier protection methods will prevent oral-anal transmission.

    Hepatitis A is an acute infection, which will clear from the body (after a few weeks) and not lead to chronic infection or liver disease. It does, however, cause liver inflammation, and the most common symptoms are jaundice (yellowing of the skin and/or eyes), liver pain (under your right side ribs), nausea, fever, fatigue and loss of appetite.  Symptoms are more common in older people than younger people. Sexual contact should be avoided during acute illness.  There is no special treatment for hepatitis A – just plenty of rest, good diet, and fluids.  Most people get well on their own, within a few months.

    If you have previously had hepatitis A you cannot get it again (your body will have formed antibodies against it). To avoid hepatitis A altogether (as it can have very unpleasant symptoms lasting weeks, and in severe cases hospitalisation) a vaccine is available and is recommended especially for HIV-positive people. Ask your doctor if the hepatitis A vaccine may be suitable for you.

    About Hepatitis A (HAV):




    Hepatitis Queensland:  07 3846 0020 or 1800 437 222 or www.hepqld.asn.au

  • Hepatitis B Virus (HBV)

    Hepatitis B virus (HBV) is transmitted by contact with blood, semen or vaginal fluids. It is many times more infectious than HIV, so it is easily passed on during sex without a condom or other barrier protection.  Oral sex is a risk if there are cuts, wounds or abrasions in the mouth.  It can also be passed on from a mother to her baby during birth, although treatment for the baby at birth can prevent this.  Like hepatitis C, hepatitis B is also a risk if injecting drugs and sharing needles and equipment.

    Hepatitis B can lead to cirrhosis (scarring of the liver), liver cancer or liver failure if it is not diagnosed and managed. These serious liver-related complications from hepatitis B are a leading cause of death among HIV-positive people.  Early diagnosis and treatment (along with 6 monthly check-ups) is imperative to prevent these outcomes.

    Worldwide 240 million people have been infected with hepatitis B, and about 600 000 people die every year due to the consequences of hepatitis B. In Australia, there are an estimated 213,000 people living with chronic hepatitis B infection1nearly half of those are undiagnosed (untested).  Chronic hepatitis B occurs in about 3% of gay men, and about 6% of HIV-positive men. Men who have sex with men (MSM)are about 10 times more likely to get hepatitis B than the general population.

    Most adults (about 95%) who have been exposed to hepatitis B may naturally clear the virus during the acute (short-term) stage of the infection – because their immune system is able to mount an attack on the virus. Although some people with chronic (long-term) hepatitis B may experience an inactive (latent) state of the condition, with minimal liver health impacts, the condition can persist a lifetime as there is no cure.  It may also ‘flare up’ at any time without you noticing symptoms or feeling unwell.  With appropriate monitoring (every 6 months) hepatitis B can be treated when needed to help prevent serious liver damage.  If you have hepatitis B, regular (6 monthly) liver function monitoring with your doctor or specialist is recommended.

    Symptoms in the acute stage of hepatitis B infection might not occur, but if they do you may notice jaundice (yellowish eyes and skin, pale stools or dark urine), tiredness, nausea, vomiting, and abdominal, muscle and joint pain. Symptoms are uncommon in chronic infection – but they are similar to above, but may also include liver pain (in the upper right side of your abdomen, just under the rib cage).

    Some of the antiviral treatments used for HIV also have activity against HBV, so both conditions can be treated at once with HIV antiviral treatments alone. Your HIV specialist can advise you about those treatments.  For people who only have hepatitis B (but not HIV) other antiviral treatments may be used.  Treatment may not be appropriate for everyone – depending on your liver health, stage of the condition and other health issues.  Your doctor or specialist will advise when treatment is recommended.

    A vaccine is available to prevent hepatitis B, and is highly recommended for HIV-positive and HIV-negative gay men. For the vaccine to be effective, you must have all three doses (injections) over 6 months.  Once you are immune you cannot get hepatitis B, and you do not require a vaccine booster shot later.

    Using condoms and dams (barrier protection) and not sharing sex toys (unless thoroughly washed in warm soapy water) will prevent exposure to hepatitis B. However, your best form of prevention is to be vaccinated for hepatitis B (and hepatitis A at the same time).

    People who inject drugs should use new sterile fits (needles and syringes) and use their own equipment (spoons, tourniquets, filters, swabs), and dispose of injecting equipment in an approved sharps container. Avoid sharing personal grooming items (toothbrushes, razors, tweezers).

    1. Kirby Institute, Annual Surveillance Report, 2015-p12.

    About Hepatitis B (HBV):




    Video (Liver Health Checks): www.hepatitisaustralia.com/videos/

    Hep B Support Group: http://hblist.net/

    Hepatitis Queensland:  07 3846 0020 or 1800 437 222 or www.hepqld.asn.au

  • hepatitis C Virus (HCV)

    Hepatitis C is a blood-borne virus (BBV) which is commonly passed on through unsafe injecting drug use (sharing of needles and injecting equipment), or in some cases the sharing of unsterilized equipment such as clippers, razors, toothbrushes and tweezers where there may be small amounts of blood. People in Australia who received blood or blood products prior to 1990 may have been exposed to HCV.  A small number of needle-stick (sharps) injuries have transmitted HCV (in occupational settings), and similarly some people have been infected through unsterile tattooing or body piercing.

    In the past, sexual activity was thought to be a low risk for hepatitis C transmission. Although still uncommon, sexual transmission of hepatitis C is increasing among gay men and men who have sex with men (MSM).

    Sexual risk factors occur in the absence of condoms where there may be cuts, wounds, sores, abrasions or tears that may not be easily seen (with tiny amounts of blood present). Other blood exposure risks include fisting, rough sex, prolonged sex, group sex, and sharing unwashed sex toys, snorting straws and barrels for ‘booty bumping’ (anal drug administration). Using condoms and gloves with water-based lube, and thoroughly washing sex toys in warm soapy water, will prevent sexual transmission of hepatitis C (as well as protecting against other STIs). Vaccinate against Hepatitis A and B to avoid their concurrent sexual risks in these situations.

    In non-sexual settings, people who inject drugs should use new sterile fits (needles and syringes) and your own equipment (spoons, tourniquets, filters, swabs). Injecting equipment should be safely disposed in a sharps container, to reduce the risks of HCV transmission (such as accidental needle-stick injury).  Avoid sharing personal grooming items (toothbrushes, razors, tweezers).

    There is no vaccine available to prevent HCV, but it can be cured.  Highly effective oral pill-based treatments are now available which offer up to 95% cure rates of HCV within 8 to 12 weeks of treatment (in most cases).  Over time, it is expected that exposure to HCV will diminish due to the effectiveness of these new curative treatments – simply put, less people will have HCV in the long run, as we move towards virtual elimination of HCV.  However, you can be reinfected with HCV, as is the case with all curable STIs (except hepatitis A – which you can only get once).

    Approximately 10% to 13% of PLHIV also have HCV coinfection. The prevalence of HCV among gay men without HIV is estimated at about 8%. In the total population HCV prevalence is much higher compared to HIV prevalence, so exposure risks to HCV can be fairly common.  In 2014, over 230,000 people were estimated to be living with chronic HCV.  As above, this will diminish over time as more and more people are cured of HCV through the new effective treatments for it.

    25% of people clear the hepatitis C virus naturally without treatment, but the remainder go on to chronic infection (with 1% progressing to liver cancer) and will require treatment. People with HIV/HCV are less likely to clear the hepatitis C virus naturally, but are equally as likely as others to clear the virus with the new hepatitis C treatments (and achieve HCV cure).

    Regular testing for HCV is recommended, as it is estimated that 15% with chronic HCV do not know they have HCV. Ask for a HCV test when you have your regular STIs screening tests.  Like HIV, it can take up to 3months (but most often within 6 weeks) for antibodies to form after exposure to HCV – this is called the window period.  People who have had a previous HCV infection may have antibodies for life, so a PCR (viral load) test may be used to confirm a current HCV infection.

    Hepatitis C is best treated early before it causes permanent damage to the liver. Aside from seriously affecting your liver health, symptoms of HCV infection may include liver pain, excessive fatigue/tiredness.  Some people don’t get any symptoms, so testing can be the only way to tell if you have HCV.

    About Hepatitis C (HCV):




    About HIV/HCV coinfection:



    About HCV Sexual Transmission (for gay men):



    Hepatitis Queensland:  07 3846 0020 or 1800 437 222 or www.hepqld.asn.au

  • Herpes Simplex Virus (HSV)

    Herpes is caused by the Herpes Simplex Virus (HSV). There are 2 types of HSV:

    Type 1, commonly called cold sores, occurs around the mouth, lips and nose; and

    Type 2, or genital herpes, appears on the genitals or around the anus.

    Both types cause irritating blisters that develop into painful ulcers. Stress is a major factor in an outbreak of herpes blisters. Sunburn can also trigger this.

    After initial infection, the virus may remain latent within the tissue and reactivate in times of stress or immune deficiency. HSV is highly infectious and is transmitted sexually and by close person-to-person contact and sexual intimacy – such as kissing, and oral, anal and vaginal sex – or from mother to baby during childbirth.

    Condoms help prevent transmission of herpes during anal or vaginal sex, although they will not prevent other transmission risks such as kissing, oral sex and skin-to-skin contact.

    Herpes Type 1 is extremely common in Australia, and 10% of adults have Type 2.

    There is no cure for HSV but symptoms can be controlled with herpes antiviral medications.

    While herpes is not life-threatening, and not all people who have it suffer from blister outbreaks, those who do experience outbreaks find that topical medication ointment eases the pain and can help speed recovery when blisters appear.

    There is a high risk of herpes spreading between sexual partners before, during, and for the week following a blister episode. Even when a person has no symptoms, herpes can be directly spread to their partner, if the infected person is currently “shedding” the virus (replicating) at the time of sexual intercourse or oral sex.

    Genital herpes is a risk factor for getting or passing on HIV, due to blistering sores and ulcers where there may be blood-to-blood contact.

    About Herpes:




  • Herpes Zoster Virus (HZV) – also known as Shingles

    Inflammation of the peripheral nerves, due to infection with the herpes virus known as varicella-zoster or HZV. Initial infection with this virus causes chicken pox (varicella). After initial infection the virus may remain latent within the tissues and can reactivate as shingles in the presence of HIV if the CD4 cell count falls below 500. Shingles appear as painful, itchy blisters on the skin that form hard scabs as they heal. Blisters most commonly occur on the chest, back and stomach but other areas of skin can be affected. There is no cure for shingles but symptoms can be controlled with antiviral therapy and pain management.

  • High Density Lipoprotein (HDL)

    A type of cholesterol (blood fat) transporter that is protective against inflammatory diseases (such as heart disease). HDL is called ‘good cholesterol’ since it can be eliminated from the body carrying away ‘bad (LDL) cholesterol’ with it thus preventing it from building up in arteries (major blood vessels). The ratio of total cholesterol to HDL cholesterol (obtained by dividing the number of each by each other) is an important measurement for predicting artery diseases (such as atherosclerosis) which your doctor can run blood tests for. The goal is to keep the ratio below 5.0, but it’s best below 3.5. HDL measurement on its own should generally be 1.0, but above >1.0 is better if your risk of heart disease is already high (e.g. a previous heart attack or stroke).

    See Low Density Lipoprotein (LDL) and Triglycerides.

  • HIV Wasting

    Also known as Cachexia

    Physical loss of body weight and muscle mass frequently associated with chronic disease, such as cancer or AIDS. HIV antiretroviral treatment prevents the development of AIDS, and therefore also prevents HIV wasting.

  • Human Immunodeficiency Virus (HIV)

    HIV is a retrovirus that is not able to replicate on its own without entering and destroying the human host CD4 T cells, and other cells of the immune system. If left untreated, HIV attacks and eventually depletes the immune system (the body’s protection against disease) whereby the number of functional (uninfected) CD4 T cells (immune cells) decreases to very low levels. At that point, this can lead to AIDS (Acquired Immune Deficiency Syndrome) whereby a person becomes highly susceptible to many common communicable diseases (called Opportunistic Infections) – some of which are life-threatening conditions, that the body can no longer fight off on its own without HIV ARV treatment and other drugs. There is currently no cure for HIV. However, HIV antiretroviral treatment stops the progression to AIDS by keeping the virus supressed and the immune system working well.

    There are two types of HIV:  HIV-1 and HIV-2. HIV-1 is the most prominent in Australia. HIV-2 is more common in Africa and other nations. Both types have the same effect where almost all aspects of the immune response are altered. Both types of HIV are amenable to effective HIV antiretroviral treatment, which suppresses the HIV virus and restores a healthy immune system.

    HIV is spread through bodily fluids and can be transmitted through non-condom sex, by sharing needles/syringes, or from mother-to-child during pregnancy or through breastfeeding. HIV is treated using a combination of anti-HIV medication (combination therapy- cART) which stops the virus spreading through the body.

  • Human Papilloma Virus (HPV) – Anal and Genital Warts & Cancer

    The Human Papilloma virus has over 100 strains (subtypes). Types 6 and 11 are the main cause of genital and anal warts (venereal warts). Types 16 and 18 are the main cause of anal and cervical cancer (in women), and in rarer cases may also cause cancer of the penis, vagina, vulva, head and neck. Common warts on the hands and feet are NOT from the same HPV subtypes, and these do not affect sexual health.

    Not everyone with HPV gets warts, and they can take a long while to develop after infection (up to a year), but the virus can still be transmitted even if warts are not present.

    HPV is a very common virus (in about 30% of the population) and most sexually active adults have likely been exposed to HPV. Although HPV can last in the body for years or decades without any symptoms (in a latent state), many people will naturally clear the virus over time (within a year or so, although this is less likely for the HPV cancer risk types). Its only when the immune system can’t fight off the infection that some strains can lead to cancer, but very few high risk HPV cancer types do lead to cancer (although it’s hard to predict, and that is why check-ups/screening are so important).

    In most people who have been exposed to HPV infection it does not cause morbidity (health concerns), but it can be a concern where there is immune compromise and inflammation (such as from HIV) when HPV can reactivate. HIV-positive people co-infected with HPV have much higher incidence rates of anal and cervical cancers (and pre-cancerous lesions) than those without HIV; although the prevalence (number of HIV-positive people) this affects remains low, but is increasing. That said, in most cases pre-cancerous lesions (low grade lesions) disappear on their own (without treatment) and do not lead to cancer (high grade lesions).

    Transmission: HPV can be contracted during non-condom anal, vaginal or oral sex, and by close physical contact with the genital area or by sharing sex toys, even if the infected partner has no obvious signs or symptoms of HPV. Contact with warts (if they are present) is a risk as well. Using condoms, and effectively washing sex toys between partners, will decrease the chances of getting HPV.

    Prevention of HPV-associated cancers is achieved through early detection (screening) and medical management, to prevent progression to invasive cancer. For anal cancer, an annual Digital Anal-Rectal Examination (DARE) and examination by a sexual health physician is recommended for HIV-positive men, to check for the presence of anal lesions. A yearly PAP smear (Papanicolaou test) is also recommended for HIV-positive women to detect cervical lesions. Individual needs vary, so speak to your doctor about recommended screening frequency and screening procedures.

    Like all cancers, it is important to avoid or quit smoking, as smoking highly elevates cancer risk, and also reduces the likelihood of clearing the HPV infection. For women, some oral contraceptives and IUDs have been shown to increase the risk of HPV-associated cancers. Speak to your doctor about cancer risk prevention.

    Prevention of HPV-associated warts includes avoiding touching them because they can be contagious. Warts are best removed by your doctor (often freeze removed or by minor surgery) or they can be treated with topical creams (e.g. Aldara [imiquimod]), but they may re-emerge. Removing the warts does not remove the infection.

    Two vaccines are available and funded (Cevarix & Gardasil) for girls and boys (to age 13) which protects from acquiring strains of HPV that cause cervical and anal cancer and warts (Gardasil only). In practice, some sexual health doctors may offer the vaccine to women and men to the age of 26 (depending whether you have been exposed to HPV already). If you already have HPV then the vaccine is of no value, as it will not alter or treat any pre-existing HPV infection or the development of any consequences of the infection. However, some research has shown that even if you have had prior HPV exposure you may still benefit from the HPV vaccination, although the therapeutic effect is uncertain. Further study is needed in this area.

    About HPV:




    About Anal Cancer (for Gay Men):


    About HPV (for women):


    About HPV Vaccination: http://www.immunise.health.gov.au/internet/immunise/publishing.nsf/Content/immunise-hpv


    About HPV vaccination in HIV-positive and HIV-negative gay men:


  • Immune Deficiency

    A disorder of the immune system characterised by a decrease in the number of lymphocytes (either B-cells or T-cells), which results in a decreased ability to fight infections. Lymphocyte deficiency can lead to the development of certain cancers, recurring infections and opportunistic infections.

  • Immune Response

    The immune response functions to protect the body from disease. It is a highly interactive process between the cells of the immune system. The immune response involves the production of antibodies by B-cells, the activation and growth of CD4 cells and CD8 cells and the release of cytokines. Memory T cells are formed as part of the immune response. These cells remain in the blood long after infection has resolved and mount a very rapid response to any subsequent re-infections of the same ‘invading’ disease. This process is called immunity.

  • Immune System

    A collection of body organs, cells and responses within them that operate together to protect the body from infections and diseases. The immune system is composed of the spleen, thymus gland, lymph nodes, lymphocytes, macrophages and protein. It has two functions:

    1. It recognises substances that are foreign to the body that may cause disease, and then
    2. It works to dispose of these foreign substances and expel them from the body.

    If this system is impaired (weakened) severe infections and other conditions may develop. HIV hides within the immune system (and weakens it) impairing the second response above, so HIV cannot be expelled from the body and so persists in the body. A cure for HIV is the goal of HIV research.  Meantime, HIV antiretroviral treatment slows down the HIV virus so it can’t do as much damage to the immune system, by keeping the viral load supressed to low undetectable levels.

  • Immunocompromised

    A state in which the immune system is impaired due to the administration of immunosuppressive drugs, malnutrition or the invasion of viruses like HIV. Untreated HIV causes immune compromise.  Treated HIV brings about immune reconstitution (restoration of the immune system). The only effective treatment for this to occur is HIV antiretroviral (ARV) therapy.

  • Inflammation

    The body’s response to tissue damage or infection. The function of inflammation is to promote tissue repair and prevent the spread of infection though the body. Signs of inflammation include swelling, redness, pain and sometimes loss of function of the tissue involved. The degree of inflammation depends on the amount of tissue damaged or the type of infection. In certain infections the inflammatory response may be excessive, causing destruction of tissue.

  • Integrase Inhibitors

    Also known as Integrase Strand Transfer Inhibitors (INSTIs)

    Integrase Inhibitors prevent HIV from inserting (integrating) its genetic material into host cell chromosomes (DNA). This is only one step in the process of HIV invasion and replication in the host human immune cells, so integrase inhibitors are used in combination with other HIV antiretroviral treatments (and their function is to block other steps in case HIV is able to get around this step). Integrase inhibitors do not interfere with known human cellular processes (they interrupt the HIV virus process) and so this class of drugs has few toxicities or side effects. INSTs are the fifth (5th) class of HIV drugs to emerge since the advent of HAART combination treatment in 1996, which initially comprised nukes, non-nukes, and protease inhibitors, then entry/attachment inhibitors…Then came Integrase Inhibitors, to block the integration step of the HIV virus replication lifecycle.

  • Kaposi’s Sarcoma (KS)

    Is a cancer tumour caused by human herpes virus 8 (HHV8), also known as Kaposi’s sarcoma-associated herpes virus (KSHV). It became widely known in the 1980’s as an AIDS defining illness. The cause for this cancer –HHV8 – was discovered in 1994. KS appears as lesions on the skin and internal organs. Lesions may be red, purple or black and are initially flat and usually painless. KS is more likely to develop if the CD4 cell count is below 250 and the lesions may become more destructive as HIV infection progresses. HIV ARV treatment usually resolves KS, however lesions can persist and treatment may include surgical removal, cryotherapy, radiation therapy and chemotherapy.

  • Latency

    A stage during an infection that is asymptomatic (i.e. has no obvious symptoms or signs). The infective agent (e.g. virus, bacteria) exists in an inactive state, concealed within the tissues. Latent infections have the potential to reactivate (e.g. Herpes Zoster Virus).

  • Lesion

    A distinct area of abnormality of tissue (e.g. tumour).

  • Leucocytes (white blood cells)

    Most leucocytes are mobile white blood cells that move through the blood searching and destroying foreign substances. They are immune system cells that function to protect the body from disease. Leucocytes include macrophages, lymphocytes, neutrophils and basophils.

  • Lipodystrophy

    A condition caused by the defective metabolism of fat, causing a syndrome of insulin resistance, fat distribution (lipoatrophy) and blood fat abnormalities. Lipodystrophy is associated with the use of some older HIV ARV treatments, which are less used now for that reason. Lipodystrophy results in abnormal deposition of fat usually an accumulation around the stomach and sometime the upper back along with wasting of the face, limbs, and buttocks. This condition is now uncommon with newer HIV ARV treatments. There is a cosmetic dermal (under the skin) injectable facial treatment available for people living with HIV (PLHIV) to correct facial lipoatrophy, called Sculptra (poly lactic acid – PLA).

  • Liver Function Tests (LFTs)

    A simple blood test that shows how well your liver is functioning, and whether you have any active liver damage. There are a number of different liver enzymes that can be tested for. The main two (2) that look for whether the liver is inflamed are Alanine Aminotransferase (ALT) and Aspartate Transaminase (AST). When these are high they indicate damaged caused by alcohol, drugs, chemicals or hepatitis.

  • Localised

    A condition that is confined or isolated to one place in the body.

  • Long-term Non-Progressor (LTNP)

    People living with HIV (PLHIV) who have had no symptoms for more than 10 years and a normal CD4 cell count without ever taking HIV antiretroviral treatment. LTNPs eventually need HIV ARV treatment. However, “Elite {HIV] Controllers” may never need HIV ARV treatment, but this is extremely rare, as the majority of PLHIV will need HIV antiretroviral treatment, and this treatment is best considered early, close to HIV diagnosis.

  • Low Density Lipoprotein (LDL)

    A type of cholesterol (blood fat) that causes inflammatory diseases (such as heart disease). LDL is called ‘bad cholesterol’ since it can build up in arteries (major blood vessels). Whilst LDL is not assessed alone to predict heart disease risk, it is an important part of assessing the overall absolute risk. The goal is to keep LDL-Cholesterol to below <2.5, or <2.0 is better if your risk of heart disease is already high (e.g. a previous heart attack or stroke).

    See High Density Lipoprotein (LDL) and Triglycerides.

  • Lumbar Puncture (Spinal Tap)

    A diagnostic or treatment medical tool that involves the insertion of a needle into the lower spine. A lumbar puncture is performed to draw fluid from the spine to test for infections or cancers of the central nervous system, or to administer anaesthetic or some other specific treatments.

  • Lymph Nodes (Lymph Glands)

    Numerous small organs distributed along the length of the lymph vessels. Lymph nodes play a major role in protecting the body from disease. Foreign substances (antigens) are removed from the body within the lymph nodes by way of the immune response. Lymphocytes and macrophages are located in the lymph nodes where they are in prime position to encounter and destroy antigens. Lymph nodes are a major site of HIV infection.

  • Lymphatic System

    The lymphatic system consists of the thymus gland, spleen, tonsils, lymph fluid and lymph nodes that are all connected by lymph vessels. It functions to drain fluids of foreign substances before it enters the blood. Macrophages and lymphocytes are located within the lymph nodes and can migrate anywhere within the body, via lymph vessels, to sites of infection.

  • Lymphocytes

    Cells of the immune system that function to protect the body from disease. They are divided into two main classes: T-lymphocytes (T-cells) and B-Lymphocytes (B-cells). T-cells are divided into two subclasses:  CD4 cells and CD8 cells. B-cells and T-cells are responsible for mounting the immune response.

  • Lymphogranuloma Venereum (LGV)

    LGV is caused by the same type of bacteria that causes Chlamydia – – Chlamydia trachomatis – but it is a different type (or strain) of that bacteria which causes very different (and potentially more severe) symptoms than that of chlamydia.

    The LGV strain causes painless genital and rectal ulcers (a small sore that might not be easily seen) that heals and disappears quickly without treatment; but the infection remains and invades the body’s lymph glands in the pelvis and groin – 2-6 weeks later these then become swollen and painful. Additional symptoms that may occur such as pain in the lower abdomen and back (due to lymph blockages in the pelvis/groin region), as well as malaise (fatigue), fever, chills, and joint and muscle pain. Rectal sores, bleeding and discharge are more common among people who engage in receptive anal sex (men and women). If the infection is not treated, serious abscesses (pus filled sores), fistulas (tears in the anal lining), and permanent scarring or extreme swelling/inflammation of the genitals and anal opening can occur (a condition called rectal proctitis). Constipation and cramping may also occur.

    LGV is uncommon in Australia, but following outbreaks of infection amongst men who have sex with men overseas, there has been a recent small increase in local Australian cases.

    Exposure to LGV occurs through anal or vaginal sex without a condom, or through oral sex.

    Condoms and dams are the best form of prevention, although they may not prevent all infection risks.

    Diagnosis of LGV is primarily based on symptoms, as well as a chlamydia swab test. Regular testing is recommended, every 3 months if you are sexually active and at risk.

    Treatment for LGV is with a course of antibiotic tablets, that need to taken for at least 3 weeks.

    It is important to avoid sex until the infection clears up (through treatment) and inform sexual partners (see STI Prevention – Contact Tracing) to prevent transmission and reinfection. You can get LGV again even if you had it before.

    About LGV:




  • Macrophages

    A type of leukocyte that has many functions in protecting the body from disease. Macrophages primarily target antigens that are circulating freely in the blood but also attack cells infected by virus or bacteria and cancer cells. They kill by literally engulfing their targets and digesting them. Macrophages also have an important role in the immune response. Once a macrophage has digested an antigen it stimulates the immune response by presenting part of the antigen to lymphocytes. They also release cytokines that enhance CD8 cell function. HIV can infect macrophages inhibiting these important functions.

  • Monotherapy

    The use of a single drug for treatment of a medical condition. This is not considered optimum or effective therapy for the treatment of HIV. HIV treatment requires combination (antiretroviral) therapy to work effectively against HIV, and to stop the development of drug resistance.

  • Mutation

    An alteration (change) in the genetic material (DNA or RNA). Most mutations are natural processes that occur during cell replication. The alteration in the genetic material is permanent and is carried during replication to new generations. Mutations also arise in viruses, bacteria, fungi, protozoa as well as human cells. HIV is highly susceptible to mutation, and mutations are a major cause of the development of HIV drug resistance. HIV is less able to mutate when combination HIV antiretroviral treatments are used, and adherence is high (taking the medications daily as prescribed, without missing doses).

  • Myalgia

    A tenderness or pain in a muscle or muscles.

  • Myopathy

    An abnormal condition of a muscle or muscles characterised by weakness which may be progressive. Myopathy may be a reaction to HIV antiretroviral treatments or HIV itself may be responsible.

  • Nadir

    Most often refers to the lowest ever CD4 count recorded on your medical records. The CD4 nadir, depending whether it is low or high, is predictive of future illnesses (or wellbeing) and response to HIV therapy (complete or diminished). Current treatment guidelines recommend stating HIV antiretroviral (ARV) treatment before the CD4 count decline, to keep the nadir high.

  • Naïve cells

    Immature B or T (lymphocyte) cells. They are inactive cells that have not been exposed to foreign antigens. Once exposed to antigen, a naïve cell matures, then multiples rapidly and begins to perform its function. These cells are referred to as activated lymphocytes.

  • Neutropenia

    A decreased number of neutrophils circulating in the blood. Neutrophils are a type of leukocyte that target and destroy bacteria. Neutropenia may lead to an increased susceptibility to bacterial infections. There are many causes of neutropenia, but it may be a symptom of HIV related conditions (e.g. Mycobacterium Avium – MAC) or a reaction to HIV antiretroviral treatments or other drugs.

  • Non-nucleoside Reverse Transcriptase Inhibitors (NNRTIs) Also known colloquially as “Non-Nukes”

    A class of antiretroviral drugs. NNRTIs act by binding to the HIV enzyme, reverse transcriptase, and blocking its function. This inhibits the translation (change) of viral RNA to DNA and halts the replication process of HIV virus.

  • Non-Specific Urethritis (NSU)

    Please see Gonorrhoea

  • Nucleoside Reverse Transcriptase Inhibitors (NRTIs) Also known colloquially as “Nukes”

    A class of antiretroviral drugs, also known as nucleoside analogues. NRTIs act by inhibiting the function of HIV enzyme, reverse transcriptase, prematurely terminating the construction of HIV DNA. This halts the HIV virus replication process.

  • Opportunistic Infections (OIs)

    Infections that develop if the immune system is severely damaged. OIs can occur in people without HIV, but can be more serious and severe for people with HIV if there is advanced immune deficiency, in the absence of effective HIV antiretroviral treatment. OIs are due to viruses, bacteria, protozoa and fungi that exist either normally within the body or commonly in the environment. They may be new infections that do not cause serious disease if the immune system is intact, or previously acquired infections that enter a latent period and are reactivated if the immune system is damaged. The risk of developing an OI is greater is the CD4 cell count is below 200, at which point other drug treatments are often used to prevent and treat these infections. However, taking HIV antiretroviral (ARV) treatment – which supresses the viral load to low levels, which in turn gives rise to gradual increases in the CD4 cell count restoring the immune system – is the best way to prevent OIs from occurring. OIs are rare if HIV ARV treatment is taken daily. Thus, for people taking effective HIV ARV treatment (with improved CD4 immune T cell counts), these OI conditions are highly unlikely to happen due to the immune reconstitution benefits of HIV ARV treatment. Without HIV antiretroviral treatment, OIs can occur and the CD4 count drops to very low levels, this is then called ‘AIDS (Acquired Immune Deficiency Syndrome)’ and the risk of death is also increased. Examples of AIDS Opportunistic Infections (OIs) are:  Cryptococcosis;, Cryptosporidiosis; Cytomegalovirus (CMV); Progressive Multifocal Leukoencepalopathy (PML); Non-Hodgkin’s Lymphoma(NHL); Karposi’s Sacoma (KS); Pneumocystis Jiroveci pneumonia (PJP); Mycobacterium Avium Complex (MAC); Toxoplasmosis; Microsporidiosis; Molluscum contagiosum. OIs can affect every body part, and can also affect the brain and lead to a condition called AIDS Dementia Complex (ADC). Treatment with HIV ARV therapy halts and reverses many OIs, including ADC.

    Note: We have not defined many of these OIs in this guide because they are rare when effective HIV ARV treatment is taken daily.

  • Oral Hairy Leukoplakia (OHL)

    A condition that appears as thick white growths, typically located on the sides of the tongue or the inner cheeks. OHL is caused by the Epstein-Barr virus. OHL does not cause serious illness nor is it transmitted from one person to another. It is seen frequently in HIV infection when the CD4 count is below 500. Usually the growths clear without treatment within a month. Antiviral drugs are an effective treatment if the condition persists.

  • P24 Antigen Test

    A test that measures the amount of P24 antigen (a protein in the core of HIV) in the blood. The P24 antigen test can be used to help diagnose early HIV infection before antibody production begins. It was once used to estimate the rate of viral replication; however it was unreliable for this purpose. HIV viral load (HIV RNA) tests now measure this.

  • Partner Notification

    Partner Notification (or contact tracing) is where any sexual partners you have had since you may have become infected with an STI should also go for sexual health test check, as they may also need to be treated.

    Not all STIs need contact tracing (such as herpes or genital warts), but the more serious and health impacting conditions do (such as chlamydia, gonorrhoea, syphilis, hepatitis, etc.).

    Your diagnosing doctor can discuss partner notification needs with you.

    If contact tracing is recommended, there are ways to let your partners know they may have been exposed to an STIs without disclosing your identity (i.e. anonymously).

    Click here to notify your partners now:

    www.letthemknow.org.au/ or

    http://bettertoknow.org.au/notify or


  • Pathogen

    Any disease producing agent. Pathogens include viruses, bacteria, protozoa, fungi, parasites and toxins.

  • Peripheral nervous system

    The part of the nervous system consisting of the nerves that lie beyond the brain and spinal cord (central nervous system).

  • Peripheral Neuropathy

    A degeneration or damage of the peripheral nerves. The most common type seen in HIV infection occurs at the end of the nerve, affecting the soles of the feet, tips of the toes or tips of the fingers. Symptoms include numbness, tingling, a burning sensation, sensitivity and sometimes pain. In advanced cases these may be accompanied by leg and arm weakness. Peripheral neuropathy may be a reaction to HIV antiretroviral treatment or HIV itself may be responsible.

  • Persistent Generalised Lymphadenopathy (PGL) Also known as Lymph Gland Swelling

    A condition commonly seen in early HIV infection characterised by swelling of the lymph nodes that persists for at least one month. PGL is a result of intense stimulation of lymphocytes within the lymph nodes in response to the presence of HIV.

  • Placebo

    A placebo is usually an inactive substance (fake medication) made to resemble a real (active) medication, which is used in clinical trials to help compare results against the effectiveness of the active drug (real medication) under trial. A placebo drug eliminates psychological response effects because participants in clinical trials do not know whether they are taking the real drug (under trial) or a placebo.

  • Platelets

    Particles in blood that help stop bleeding if you cut or injury yourself. A low platelet count (called thrombocytopenia) can cause spontaneous bleeding (haemorrhage) and bruising. A high platelet count (called thrombocytosis) can cause thrombosis (excessive clotting of blood restricting blood flow). Extremely elevated platelets can cause haemorrhage. Your doctor usually measures your platelet count on routine blood tests.

  • Pneumonia

    Inflammation of the lungs. There are many causes of pneumonia including viral, bacterial, protozoal and fungal infections. Pneumonia may involve one or both lungs. Symptoms vary depending on the cause but cough, chest pain, fever and shortness of breath are common. Pneumonia is a serious lung condition which requires medical treatment.

  • Post-exposure Prophylaxis (PEP)

    HIV drugs given to prevent HIV taking hold after exposure risk to an infection. PEP must be taken within 72 hours (preferably within 24 hours) of a risk exposure to HIV. PEP must be taken daily for one (1) month to ensure the greatest chance against HIV infection taking hold. In Queensland, PEP starter packs are available from all major hospital Accident and Emergency (A&E) departments, or any Sexual Health Clinic. For information about where to access PEP call 13-HEALTH or visit: www.health.qld.gov.au/publications/clinical-practice/guidelines-procedures/pep-brochure.pdf  or http://www.endhiv.org.au/clinic-search/ (an interactive search engine for locating your closest PEP access point in Queensland).

  • Pre-exposure Prophylaxis (PrEP)

    Use of certain HIV antiretroviral drugs that may lower the overall risk of acquiring HIV, if condoms are not used. PrEP is taken by the HIV-negative sex-partner before and after non-condom sex, and may provide increased protection against getting HIV. PrEP is currently unapproved in Australia, although it is currently available in Australian clinical trials. If you are interested in PrEP you are best advised to speak to a sexual health or HIV doctor whether PrEP is right for you and whether you can obtain it by entering a trial or other means (such as ordering it online as cheaper generic medicine with a prescription). Overseas research and experiences, where PrEP is approved and available, suggest it may offer a significant level of increased protection against acquiring HIV. However, condoms offer the greatest protection against HIV. More information about PrEP is available here:


  • Primary HIV Infection

    – see Acute & Primary HIV Infection

  • Prognosis

    The probable future course of a disease or condition. What can be expected health-wise from having a particular disease or condition, based upon what is known about disease or condition. Being given a prognosis from your doctor or clinical health-care provider is one of the most important things a patient should be told about any disease or condition/illness they may have, including advice about treatment and overcoming the disease or condition.

  • Prophylactic therapy

    A drug therapy used to prevent the development of certain infections. There are two types. Primary prophylaxis is taken to prevent the onset of infections that have not developed. Secondary prophylaxis is taken after the successful treatment of an infection to prevent its recurrence. Prophylactic therapy is important in HIV as it helps prevent many opportunistic infections, but the best primary prophylactic therapy for HIV is to take daily HIV antiretroviral treatment (which prevents opportunistic infections from arising).

  • Protease Inhibitors (PIs)

    A class of antiretroviral drugs. PIs act by binding to the HIV enzyme, protease, blocking its function. Imperfect viral proteins are created and as a result immature copies of HIV are produced. These copies are unable to infect and destroy new cells.

  • Provirus

    The genetic material (DNA or RNA) of a virus that has been integrated with the DNA of a living cell.

  • Rapid HIV Testing

    Rapid HIV testing has been available in Queensland since 2013. It is a test that allows someone to undertake an HIV test and receive their results in the same appointment. Queensland currently uses the Alere Determine test, which provides results in only 20 minutes. All that is required to complete this test is a small drop of blood that is taken from the fingertip, no needles are required. Rapid HIV testing is a great benefit to the community as it removes many barriers that previously stopped people from wanting to have an HIV test. Rapid HIV testing is more convenient for people as they will no longer have to return for a follow up appointment to receive a result, the tests are provided free of charge from all sexual health clinics, and there are a growing list of community testing sites – so you may not even need a doctor’s appointment, please see www.qpp.org.au/testing  for an updated list on where to get a rapid HIV test.  Also visit www.rapid.org.au

  • Replication Also known as Viral Replication (Lifecycle)

    The process by which copies of a virus are made. Replication of HIV is regulated by three enzymes. The enzyme reverse transcriptase converts viral RNA into a DNA copy of the virus. The viral DNA is integrated into the cell’s DNA by a second enzyme, integrase. The cell is now coded to make copies of viral RNA and long chains of viral proteins. A third enzyme, protease, cuts the protein chains into smaller, usable portions necessary for production of fully formed, infections virus. The proteins and RNA are assembled into new copies of the virus, which then exit the human host cell.

  • Resistance Test Also known as Genotypic Resistance Assay (GRA)

    A laboratory test to identify which, if any, antiretroviral (ARV) drugs will not be effective against a person’s specific strain of HIV. Resistance testing is done using a sample of blood. There are two types of resistance testing: genotypic and phenotypic. The Genotypic Resistance test (GRA) is the most common test for guiding the selection of an HIV antiretroviral treatment regimen when initiating or changing antiretroviral therapy (ART).

  • Retrovirus

    A group of viruses including HIV virus, that carry their genetic material as RNA rather than DNA. Classic RNA viruses use RNA to make proteins. Unlike classic viruses, retroviruses contain an enzyme, called reverse transcriptase, that convert viral RNA into DNA before proteins are made.

  • Ribonucleic Acid (RNA)

    A complex molecule, similar in composition to DNA that controls the construction of proteins. In a cell, RNA is a single-stranded molecule that is a copy of a single gene. In some viruses, it replaces DNA as the carrier code of genes and may be single or double stranded.

  • Risk Factors

    Substances, elements or conditions of the environment or lifestyle that are thought to contribute to the progression of HIV infection, or the development of a health condition or a decline in general health and wellbeing; for example, infections caused by fungi, protozoa, bacteria, other viruses, or conditions affected by recreational drugs, excessive alcohol, smoking, unhealthy diet, high stress levels and lack of exercise. Risk factors are unique to particular health conditions or diseases, such that the risk factors of one condition may not necessarily be risk factors for another.

  • Risk Reduction Strategies (RRS) Also known as Combination Prevention

    The use of two of more prevention techniques to reduce the overall chances of transmitting (passing on) or acquiring (getting) HIV, during anal sex. These techniques and methods can include:

    1. condom use;
    2. undetectable viral load – obtained by taking effective HIV antiretroviral treatment which is known to significantly decrease the risk of transmission;
    3. PrEP – HIV-negative person taking HIV ARV treatment to prevent getting HIV;
    4. strategic positioning – being the ‘top’ [insertive partner] is less risky for getting HIV, and being the ‘bottom’ [receptive partner] is less risky for passing on HIV, during anal sex;
    5. negotiated safety – testing regularly and trusting sexual partners test serostatus results and making a range of agreements within the relationship about sexual risk taking outside of the relationship;
    6. serosorting – sex between confirmed same HIV-serostatus people; and
    7. withdrawal – before ejaculation. This is a weak risk reduction strategy since pre-ejaculate (pre-cum) can contain HIV virus. Having an undetectable blood viral load does not always mean seminal (semen) body fluid viral load will also be low, although some HIV ARV treatments (HIV drugs) penetrate the seminal tract more than some other HIV drugs.

    The best prevention method against HIV transmission is condoms. Condoms are 100% effective for prevention if used properly (and with adequate water-based lubricant and without breakage). Other methods are often combined with condoms to enhance their protection benefits. When condoms are not used, other risk reduction strategies may be less effective in prevention against HIV infection. RRS reduce risk, not eliminate risk. Condoms PLUS risk reduction strategies may provide greater risk reduction against HIV infection. Condoms are also the best way to avoid passing on or getting other sexually transmitted infections (STIs).

    If risk reduction strategies are not utilised this creates higher risk exposure to HIV. If a risk exposure occurs Post-Exposure Prophylaxis (PEP) treatment is available and should be taken within 72 hours of the risk exposure, preferably within 24 hours (see PEP for more information).

  • Sculptra® (Poly-L-lactic acid)

    An approved injectable facial dermal (under skin) filler for the treatment of HIV-associated facial lipoatrophy (fat loss in the face). Access to Sculptra is funded under the Pharmaceutical Benefit Scheme (PBS – patient medicines cost subsidy scheme) for people with HIV with moderate to severe facial lipoatrophy. Your HIV doctor can authorise and provide you the PBS script for the subsidised cost of the product. A registered HIV-trained cosmetic physician will administer the Sculptra according to that physician’s practice fee schedule. These practitioners can set their own fee levels for administering the facial injections, by charging above the listed Medical Benefits Schedule (MBS) fee, which may increase your out of pocket expenses. However, some cosmetic practitioners may reduce their fees for PLHIV, or change the Medicare schedule fee only, lowering or removing your out-of pocket practitioner fees. Contact your state PLHIV community-based organisation for more details and how to access this treatment and/or to ascertain whether there is registered cosmetic practitioner in your location or area.

  • Sero-concordant

    A sexual partnership in which both members are either HIV-positive, or both are HIV-negative.

  • Sero-discordant

    A sexual partnership in which one member of the relationship is HIV-positive, and the other HIV-negative.

  • Sero-non-concordant

    Is a sexual partnership in which one member or both members of the relationship are unsure about their HIV status.

  • Sero-sorting

    This term applies to having condom-less sex with someone with the same HIV status as your own. Some HIV-positive people choose to sero-sort with other people they know are also HIV-positive as a way to alleviate the concern, and reduce the risk, of passing on HIV to HIV-negative people, or to people who do not know their HIV status. HIV-negative people (who regularly test and know their HIV-status) sometimes also serosort, but this is riskier than when HIV-positive people serosort, because some people do not know their HIV status (because they do not regularly test for HIV) and therefore assume they are HIV-negative. Either way, not using condoms increases the risk on passing on or getting other sexually transmitted infections (STIs) and sexually acquired Hepatitis C. It is also possible for HIV-positive people to pass on their strain of HIV to another HIV-positive person – called ‘Superinfection’- but this is highly controversial since it is unknown how common (likely) this might be or how greatly it may impact on HIV antiretroviral treatment outcomes (if a new resistance was acquired). Nonetheless, serosorting can be an effective Risk Reduction Strategy when the other person’s HIV-status is accurate from confirmed testing for HIV. Effective serosorting does not work if you try to guess, or assume, another person’s HIV-status.

  • Seroconversion (Illness)

    The change in the blood from HIV antibody negative to HIV antibody positive, meaning HIV has been acquired. Seroconversion causes an immune system’s response to the presence of HIV antigens in the blood and occurs shortly after HIV has transmitted. HIV seroconversion may be asymptomatic but it is often accompanied by a ‘seroconversion illness’. Typical symptoms of seroconversion include fever, myalgia, swollen lymph glands, sore throat and rash. These symptoms usually resolve within one to three weeks, when antibody production is complete in response to HIV.

  • Serostatus

    Serostatus refers to the state of the blood in relation to the presence of antibodies or antigens. Serostatus may be either positive or negative. Also called ‘HIV-status’.

  • Sexually Transmitted Infections (STIs)

    STIs are infections passed on during sexual contact. STIs are caused by microscopic organisms such as bacteria, viruses or parasites. Examples of STIs include gonorrhoea, syphilis and chlamydia. Most STIs are treatable and curable, so regular STI testing is recommend every 3 to 6 months especially if you have multiple sex partners. Regular testing for STIs is recommended because STIs do not always have symptoms. Not all STIs can be prevented by condom use, but having vaginal or anal sex without a condom can put you at higher risk of getting some STIs. Although oral sex is not considered a risk factor for HIV, some STIs can come from oral sex without a barrier protection such as a condom or dam.

  • Shigellosis (Shigella)

    Shigellosis is caused by the shigella bacteria. It is highly contagious and can be spread by casual contact due to lack of hand washing (faecal contamination via tiny amounts of poo indirectly transferred to the mouth) and by oral-anal sexual contact (e.g. rimming or anal play).  Shigella causes diarrhoea and abdominal pain (cramps), fever, vomiting.  Symptoms can be severe.  Thoroughly washing hands with warm water and soap, washing raw fruit and vegetables, and avoidance of sexual contact with the anus, will prevent Shigella transmission to the mouth.

    Although the body will naturally get rid of Shigella (within 5-7 days), it can still be contagious for a few weeks after the diarrhoea stops (until the bacteria clears up from the bowel). People with HIV may experience more severe or prolonged shigellosis symptoms, which can result in hospitalisation in severe cases.  Although treatment for Shigella is focussed upon symptoms (such as re-hydration from diarrhoea), antibiotic treatment is recommended to reduce the duration of infection and symptoms.  Oral antibiotic resistance can occur, and so sometimes stronger injectable antibiotics may be required with repeat visits to the doctor.

    About Shigella:




  • Side Effect

    Any reaction to, or unwanted consequence of, a drug or therapy. Typical drug side effects include nausea, fatigue, rash and diarrhoea. Side effects may be short-term or long-term. Often there is treatment available for side-effects, or the causative drug or therapy is changed (if side effects are intolerable and unable to be managed).

  • Single Tablet Regimens (STRs)

    Are fixed-dose combination HIV antiretroviral treatments taken in a single pill once daily for the treatment of HIV. Combining three drugs into a single, once-daily pill reduces pill burden (amount of pills) and simplifies dosing schedules and therefore has the potential to improve and assist adherence to HIV antiretroviral therapy.

  • Sperm Washing

    A laboratory procedure that involves a clinical procedure of ‘washing’ semen from a HIV-positive male to separate the sperm from the fluid part of the semen. Because the seminal fluid contains the highest concentration of HIV, the ‘washed’ sperm should not contain any HIV. Sperm washing can be considered as a reproductive option for an HIV discordant couples in which the male is the HIV-infected partner. Because sperm washing has not been proven completely effective, couples using the procedure should be counselled regarding the potential risks for transmission of HIV. It is worth noting that this is an older procedure (and is expensive through IVF fertility programs). Modern evidence suggests that it might be possible – along with appropriate medical and clinical guidance – for HIV sero-discordant heterosexual couples to conceive a child naturally in the presence of undetectable fully suppressed viral load. This option requires careful family planning consideration and medical/clinical guidance.

  • Stigma

    A mark of disgrace associated with a particular circumstance, quality or person. Stigma begins with the devaluing of a person because of a difference which is attributed with a negative connotation. Stigma and discrimination often go hand-in-hand, as discrimination often occurs as a result of stigma and stigmatising attitudes. Stigma can disempower people, but it is equally important to note that experiences with stigma have placed some individuals into situations where they have found new coping skills, and generated emotional and mental strength and resilience building skills. Despite this stigma and discrimination need to be addressed at the community education and awareness level, through such campaigns like ENUF:  www.enuf.org.au/

    Stigma can be experienced in a variety of ways. Some examples of HIV stigma include:

    • Ignorance or false information as to how HIV is transmitted.
    • False information that HIV is highly contagious or can be caught by casual contact.
    • Moral judgements about people and assumptions about sexual behaviour (including homophobia) and/or injecting drug use.
    • Fear of death and disease.
  • Strain

    A strain is a variation of the original form. A viral strain is created when the genetic material (DNA or RNA) mutates or changes. The alternation of the genetic material may cause a change in the characteristics of the virus. Because the genetic material is copied during replication, the new copies of the mutated (changed) virus will share the same changes in characteristics. These new mutation copies of the virus are called a strain. Strains also develop in bacteria, fungi and protozoa.

  • Symptomatic

    A disease or infection, or a stage of a disease or infection that shows symptoms of that particular disease or infection. For example, the symptoms of having a head cold are a runny or blocked nose.  – also see Asymptomatic.

  • Syphilis

    SYPHILIS is caused by a spiral-like bacteria called Treponema pallidum. If syphilis is left undiagnosed and untreated it can cause very serious long term health consequences, including heart conditions, nervoussystem breakdown, brain function impacts, and death.

    Syphilis can affect anyone regardless of their sexuality. Higher rates of syphilis notifications have occurred in young Indigenous people and among HIV-negative and HIV-positive gay men.


    Syphilis is easy to catch through oral sex or from skin-to-skin contact if there is a skin rash or syphilis sores (chancre) which may go unnoticed. Therefore, even if you use condoms, sexual foreplay (skin-to-skin body contact) and oral sex are still a high risk for contracting syphilis – your sexual partner may be unaware of their infection if they haven’t been tested.

    Sexual transmission usually occurs during the primary (2-3 months) and secondary stages (2-6 months). Syphilis is highly contagious during these times, but transmission may also occur within 2 years of infection (during early latency, even without any symptoms).


    Chancre sores are generally small reddish open lesions and can occur just about anywhere, inside the mouth, on the lips, or in the genital or anal areas (and in the rectum) – making them sometimes hard to see and sometimes they are painful but can also be painless. These will often heal and disappear within a few weeks, even if untreated, and a person can still pass on syphilis without these. A rash may also occur on your palms and soles of feet or other parts of your body.

    Other symptoms may also emerge such as swollen glands, fever, headaches, fatigue, muscle and joint aches and pains, weight loss and hair loss.

    In the early stages of infection symptoms may not always occur, this is why it’s important to test regularly for syphilis if you are sexually active.

    The progression of syphilis can occur more quickly if you also have HIV, which can make syphilis harder to treat. Like all STIs it is best to diagnose and treat them early, before they progress to more serious stages.


    Ask your doctor or sexual health clinic for a test if you think you’ve been exposed to syphilis.

    There is a period of 2-3 weeks before an infection can be detected on a test, though this period can be up to 3 months. Rapid syphilis tests are also available from QPP’s RAPID clinics in Brisbane and the Gold Coast – results are provided in 15 minutes and no appointment is required (www.rapid.org.au).

    Rapid syphilis tests are only reliable if you have never had a previous syphilis infection (because antibodies can persist for life), so if you have had syphilis before you are best to test for a current new infection at your medical or sexual health clinic. If you are having any sex get a yearly test, and whenever you change sex partners. If you are having any condom-less sex, or sex with multiple partners (>10 within 6 months) or group sex, or using recreational drugs during sex – get a test every 3 months (4 times a year).

    If you are HIV-positive, consider the above testing recommendations as it is best to test every 3 months due to the added impact of having HIV and syphilis.


    If you have been diagnosed with syphilis, it is safest not to have sex, even with a condom, until 1 week after the first treatment and all symptoms have gone.

    You can get syphilis again even if you had it before. If you have previously been treated for syphilis, it is still very easy to catch again. There is no vaccine against syphilis.

    Condoms provide partial protection, but may not prevent all risks of syphilis. Syphilis can occur in the mouth, so oral sex without a condom can also be a risk. A skin rash may also occur (which can be hard to see) so any skin-to-skin body contact is also a risk. However, condoms will provide genital and anal protection, so it’s still important to use condoms to assist in the prevention of syphilis.


    Your risk of getting HIV increases when you or you partner have syphilis. Having a syphilis infection may also increase your chances of passing on HIV, as it may increase HIV viral load in semen and pre-cum (even with an undetectable HIV viral load in blood).


    It is important to inform sexual partners to prevent transmission and reinfection. Contact tracing (or partner notification) is where any sexual partners you have had since you may have become infected with an STI should also go for a sexual health test check, as they may also need to be treated. Not all STIs need contact tracing (such as herpes or genital warts), but the more serious and health impacting conditions do (such as chlamydia, gonorrhoea, syphilis, hepatitis, etc.). Your diagnosing doctor can discuss partner notification needs with you. If contact tracing is recommended, there are ways to let your partners know they may have been exposed to an STIs without disclosing your identity (i.e. anonymously).

    The following websites can assist you to anonymously notify your sexual partners:





    Syphilis is easy to treat (and cure) with penicillin injections. The length of treatment depends upon the stage the infection. If left untreated the condition enters a period of latent infection, with no obvious symptoms. At this stage, even without symptoms, the infection may cause serious damage to

    internal organs such as the heart, brain, liver, nerves and eyes. This latent stage may persist for years, or decades, and it may lead to tertiary (end stage) syphilis, resulting in conditions such as blindness, difficulty walking, talking and eating. Tertiary syphilis is very difficult to treat and is life threatening.






  • Thrombocytopenia

    A decrease in the number of platelets circulating in the blood. Platelets are cells necessary for the clotting of blood. There are many causes of thrombocytopenia including certain medications, alcohol, causing less severe platelet decrease. It can also occur at any stage of HIV and sometimes occurs when HIV antiretroviral treatment induces an immune response. It can be the first and only sign of HIV infection. It can be a serious condition leading to abnormal bleeding and in advanced cases bone marrow problems. Your doctor will usually monitor you platelet count during your standard blood tests.

  • Toxin

    A substance that interferes with the normal function of cells or tissues.

  • Treatment as Prevention (TasP)

    Growing research evidence supports HIV antiretroviral treatment as a key aspect of HIV prevention. The aim of HIV antiretroviral treatment is to prevent HIV from replicating in the body, thereby lowering viral load to an undetectable level. This not only benefits the individual by improving long term health outcome for people living with HIV (as it lowers the amount of virus in the blood and subsequent damage to the immune system), but it also substantially reduces the risk of passing on HIV to a sexual partner. HIV antiretroviral treatment is therefore proving to be an additional prevention risk reduction strategy for a person living with HIV. A second aspect of treatment as prevention includes options for an HIV-negative person to take treatment in the form of PEP or PrEP to prevent the acquisition of (getting) HIV.

  • Treatment Naïve

    –  see Antiretroviral Treatment Naïve.

  • Triglycerides

    Another type of blood fat.  When the triglyceride count is added together with HDL-Cholesterol and LDL-Cholesterol, this is what amount to the ‘Total Cholesterol’ count.  Triglycerides are a more complex form of cholesterol, that also add to the risk of cardiovascular (heart and vascular) health risk if the level is too high. Triglycerides should be kept below 1.5 to reduce the absolute overall risk of cardiovascular disease. Your doctor will routinely take blood tests to measure your triglyceride levels.

    See also HDL and LDL (Cholesterol)

  • Tuberculosis (TB)

    An infection caused by the bacteria Mycobacterium tuberculosis. The bacteria are usually transmitted by inhaling or ingesting tiny air borne droplets, from coughing and sneezing or being in the breathing zone of a person with active TB. Primary (early) infection is often asymptomatic but the bacteria remain latent in the lung cells. A secondary infection can develop if the CD4 cell count falls below 500 and the bacteria is reactivated. The bacteria cause lesions, most often in the lungs, but it may spread to other organs. Early symptoms of secondary TB are cough, fever, night sweats and weight loss. If left untreated more severe symptoms, such as haemorrhage and pneumonia can develop; TB is not common in Australia but it is a risk when travelling to countries where the prevalence is high. Antibiotics are used to treat active TB and to prevent a reactivation of latent infection.

  • Undetectable Viral Load

    The term used when HIV virus is not able to be detected in the blood – below the level of quantification using the standard viral load blood test. Obtaining undetectable viral load is the goal of HIV treatment, preserving the immune system from damage by the HIV virus, to improve health and quality of life. Having an undetectable viral load also lowers the risk of transmitting HIV to others (see Risk Reduction Strategies [RRS]). Undetectable viral load does NOT mean you have been cured of HIV, it means that HIV is not replicating very much in the body, as it would be without daily HIV antiretroviral (ARV) treatment.

  • Vaccine

    A medical preparation that contains attenuated (killed/inactive) infectious agents (e.g. bacteria, virus) that are unable to replicate, but they induce a response in the body’s immune system that protects against getting that particular live virus. A vaccine is administered to either prevent infectious disease by developing protected immunity, or to treat infectious diseases by stimulating antibody production (the body’s own defence against a disease). Respectively, these are called preventive vaccines or therapeutic vaccines. Flu Vaccines are an example of the former. HIV vaccine research is intensely focussed upon 3 areas of vaccine development:

    1. preventative vaccines (to stop HIV acquisition);
    2. therapeutic vaccines (to inactivate an existing HIV infection);
    3. curative vaccines (to permanently eradicate – cure – an existing infection).
  • Vertical Transmission

    A term used to describe the transmission of HIV from an HIV-positive mother to her baby during pregnancy or at the time of birth. HIV antiretroviral treatment taken by the HIV-positive mother during pregnancy lowers to the risk of HIV transmission to her child to about 1%. Therefore HIV antiretroviral treatment is considered to be highly protective in preventing HIV transmission to the unborn child and during birth, due to the reduction in the HIV-positive mother’s viral load to undetectable levels, which substantially lowers the risk of transmission to her child.

  • Viraemia

    The presence of virus in the blood. A term applied to viral load.

  • Viral Load (Test) Also known as HIV RNA (test)

    A blood test (taken regularly by your HIV doctor) that measures the number (amount) of HIV virus particles (copies) circulating in the blood. The viral load test is also known as an HIV RNA test – which uses Polymerase Chain Reaction (PCR) laboratory test technology. Viral load tests are used to monitor the rate of HIV replication over time. This can help make decisions on when to start HIV antiretroviral therapy, or can indicate treatment failure if a sustained increase in viral load occurs (over at least 2 tests). Small rises in viral load (in the 100’s) are known as ‘blips’, and are not clinically concerning. Larger elevations in viral load (in the thousands) are more concerning, as it might indicate that your treatments aren’t working as well as they should – your doctor will assess this. Undetectable viral load is achieved when HIV antiretroviral therapy reduces the amount of HIV RNA virus copies in the blood to less than 40 copies (per ml of blood); although new ultrasensitive tests can now measure to below 20 copies (but the basic principle is the same – i.e. there is substantially less virus circulating in blood). The goal of HIV ARV treatment is to durably keep the viral load to undetectable levels (supressed to below 40 copies), to minimise damage to the body and immune system. Taking HIV ARV therapy every day commonly results in obtaining an undetectable viral load. because HIV antiretroviral treatments are highly effective in supressing the HIV virus. Having an undetectable viral load also substantially reduces the risk of transmission of (passing on) HIV.

  • Viral Reservoirs

    Areas of the body (other than blood) where HIV may establish itself such as in lymph nodes, gut-associated lymphoid tissue (in the intestines), cerebral spinal fluid (CSF) and the brain. HIV drugs cannot reach these areas well, although some penetration does occur, but it is limited compared to drug concentration in blood. HIV antiretroviral treatment is best reducing the (circulating) blood viral load where many of the HIV target immune cells also circulate. This is another reason early HIV antiretroviral treatment is recommended (especially during acute and primary infection) before HIV has much chance at entering the viral reservoirs. It is also why early diagnosis (through HIV testing) is important so that treatment can commence before HIV has progressed throughout the body’s viral reservoirs where treatment can less penetrate.

  • Virulence

    The measure of a virus’ ability to replicate and produce disease, or a measure of a pathogens ability to invade tissue.

  • Virus

    A non-cellular particle that consists of genetic material, whether DNA or RNA, enzymes and a protein coat. Unlike cells, they do not possess the necessary machinery to replicate. For a virus to replicate, it must first infect a living cell. It uses the DNA and other machinery of a cell to make viral proteins and assemble new copies of itself. Once new viral copies are produced they exit the cell into the blood, usually destroying the cell in the process.

  • Western Blot test

    A blood test that detects the presence of specific antibodies (which are produced by the body upon exposure to infections). The Western Blot test is used to diagnose HIV infection and to confirm a HIV-positive ELISA test.

  • Window Period

    The time it takes to develop HIV antibodies in your blood after a risk exposure to HIV. If an HIV infection has occurred, then HIV antibodies will usually appear within 45 days (6 weeks) after the risk event. In some cases antibody formation may take up to 3 months to develop. The window period can be different for everybody – therefore a test for HIV antibodies may not be reliable if it’s taken before your individual antibody response has occurred, so the 3 month window period is used as a ‘catch all’ standard recommendation for repeat HIV testing. However, HIV infection (if it has occurred) is immediate (i.e. there is no HIV infection window period, only an HIV antibody window period). Post Exposure Prophylaxis (PEP) can prevent an HIV infection taking hold IF HIV antiretroviral treatment is taken within 72 hours (but optimally within 24 hours) of exposure to HIV.


This guide to HIV terminology is for people living with HIV (PLHIV) and other people with an interest in HIV.

Sometimes it can be difficult to understand the medical terminology doctors and clinical staff may use, especially if you have just been diagnosed with HIV. Social and legal terminology within the HIV community may be hard to understand as well. This is why QPP undertook the production of this resource to help PLHIV, and those affected by HIV, to navigate the world of HIV terminology.

In most cases your doctor, clinic staff and community workers will explain much of what is in this guide that is relevant to your HIV medical-care, social-care and support needs. We hope that this guide will help you talk with, and understand, your doctor and other community support workers involved on your care. Of course, the best way to understand HIV is to ask questions, so we hope this guide is a starting point for discussion.


Italicised words in this guide indicate the existence of a further description of that word in its respective alphabetical place.

The information contained within this guide is not intended as medical advice or as a replacement for medical care, testing and treatment provided by your doctor or clinical-care provider. This guide is intended for fundamental HIV education and awareness purposes only.