The three stages of HIV infection are

Explanation

HIV infection progresses through three main stages. The first stage is acute HIV infection, which usually occurs 2-4 weeks after exposure. During this period, the virus replicates rapidly, causing a very high viral load, and many people develop flu-like symptoms such as fever, rash, sore throat, fatigue, and swollen lymph nodes, although some may not notice any symptoms. Because of the high viral load, individuals are highly infectious at this stage. The second stage is chronic HIV infection, also called the clinical latency or asymptomatic stage. This stage can last for 10 years or longer without treatment, though it may progress more quickly in some people. During this time, the virus continues to replicate at lower levels while the immune system works to control it. Many people do not have symptoms or only experience mild ones, such as fatigue or recurrent minor infections. With effective antiretroviral therapy (ART), individuals can stay in this stage indefinitely and live a near-normal lifespan. The final stage is AIDS (Acquired Immunodeficiency Syndrome), which occurs when the immune system is severely damaged. This is diagnosed when the CD4 T-cell count falls below 200 cells/mm³ or when certain opportunistic infections or cancers develop. Symptoms in this stage may include chronic fever, weight loss, night sweats, persistent diarrhea, and frequent or severe infections. Without treatment, survival after reaching AIDS is typically around three years, but with ART, progression to this stage can often be prevented.