t is not known, however, why only some HIV-infected people

t is not known, however, why only some HIV-infected people develop these symptoms. It also is unknown whether or not having the symptoms is related in any way to the future course of HIV disease. Regardless, infected people will become symptom-free (asymptomatic) after this phase of primary infection. During the first weeks of infection when a patient may have symptoms of primary HIV infection, antibody testing, if performed, may still be negative. If there is suspicion of early infection based upon the types of symptoms present and a potential recent exposure, consideration should be given to having a test performed that specifically looks for the virus circulating in the blood, such as a viral load test. Once the patient enters the asymptomatic phase, infected individuals will know whether or not they are infected if a test for HIV antibodies is done. Therefore, anyone who might possibly have been exposed to HIV should seek testing even if they are not experiencing symptoms.

During all stages of infection, literally billions of HIV particles (copies) are produced every day and circulate in the blood. This production of virus is associated with a decline (at an inconsistent rate) in the number of CD4 cells in the blood over the ensuing years. Although the precise mechanism by which HIV infection results in CD4 cell decline is not known; it probably results from a direct effect of the virus on the cell as well as the body's attempt to clear these infected cells from the system. In addition to virus in the blood, there is also virus throughout the body, especially in the lymph nodes, brain, and genital secretions. The time from HIV infection to the development of AIDS varies. Rarely, some individuals develop complications of HIV that define AIDS within one year, while others remain completely asymptomatic after as many as 20 years from the time of infection. However, the time for progression from initial infection to AIDS is usually approximately eight to10 years. The reason why people experience clinical progression of HIV at different rates remains an area of active research.