Symptoms/Course of Disease
HIV progression comprises the acute, latent, and late/advanced stages. The acute stage comprises the first few weeks after infection, during which time the patient may experience "flu-like" symptoms including headache, nausea, sore throat, or fever45; other possible symptoms include swollen lymph nodes, muscle pain, and oral and esophageal sores. As HIV enters and replicates within CD4+ cells in the immune system, the viral load increases sharply, and there is a corresponding dip in the number of CD4+ cells, and an increase in CD8+ cells in the blood. During this stage, the patient is extremely infectious.
This phase usually ends a few weeks later, when the immune system is able to mount an effective response: The viral load decreases, and the number of CD4+ rises again, marking the beginning of the latent stage. At this point, the disease enters a period of clinical dormancy that could last for many years, although it can be much shorter in some patients. During this time, there may be no symptoms, and the carrier may be entirely unaware that he or she is carrying HIV. The virus, however, still continues to progress.
As CD4+ cell count decreases below 350 cells/µL, patients often develop constitutional symptoms, such as fatigue and night sweats, and become more prone to various infections. When the immune system is no longer able to fight off the infection, the advanced stage begins and is characterized by CD4+ cell counts below 200 cells/µL, the development of opportunistic infections, and a severely impaired immune system, all of which culminate into AIDS.45