Final answer:
Symptoms of HIV typically begin during the acute stage, which occurs 2-4 weeks after infection. The chronic stage follows, lasting from 3 to 20 years. During the clinical latency stage, patients may not experience symptoms.
Step-by-step explanation:
After infection with HIV, symptoms typically begin to appear during the acute stage, which occurs two to four weeks after infection. During this stage, patients may experience flu-like symptoms that can last for a few weeks. Patients with acute HIV infection have more than 500 cells/μL CD4 T cells and a large amount of virus in their blood. They are highly contagious during this stage. To confirm acute infection, a fourth-generation antibody-antigen test or a nucleic acid test (NAT) must be performed.
After the acute stage, the infected individual enters the stage of chronic HIV infection, which can last from 3 to 20 years. During this stage, there is a prolonged period without symptoms. However, the infection continues to progress, and HIV continues to infect and destroy helper T cells. Towards the end of the chronic stage, symptoms may reappear, such as fever, weight loss, and swollen lymph nodes.
During the clinical latency stage, patients have between 200 and 499 cells/μL CD4 T cells. HIV is still active but reproduces at low levels, and patients may not experience any symptoms of illness. For patients not on medication, this stage can last a decade or longer. With antiretroviral therapy, the stage may last for several decades. At the end of the latent stage, viral load increases, CD4 T-cell count decreases, and symptoms develop.