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.