Seroconversion

Primary HIV infection occurs when HIV first enters the body, it encounters the immune system and begins to produce new virus (viral replication). The virus grows rapidly and reaches peak levels that are generally associated with seroconversion and the development of flu like symptoms called the acute retroviral seroconversion syndrome.

Seroconversion is the development of detectable antibodies in the blood as a result of infection, or in other terms going from negative HIV status to positive HIV status. The body's immune system will attempt to fight off the infection by producing antibodies. Antibodies are proteins produced in the body in response to a foreigner, like HIV. They contribute to the destruction of the virus at first, but the virus eventually takes over leaving the host extremely susceptible to other infections and diseases. It has been estimated that 95 - 99% of individuals infected with HIV will seroconvert within 6-12 weeks of exposure although in some it may take longer. Two important factors in determining survival and progression to AIDS are age at seroconversion and time elapsed since seroconversion. The vast majority of people will develop AIDS within 20 years after seroconversion.

Acute retroviral seroconversion syndrome is seen in 50 - 90 % of adults recently infected with HIV. This acute phase is a non-specific, self-limiting illness similar to the flu. Symptoms like sore throat, muscle aches and pains, fever, rash on the trunk and face, headache, diarrhea and swollen glands usually develop within 2 to 6 weeks after exposure and resolve spontaneously 2 to 3 weeks later. Longer duration of symptoms has been associated with a more rapid progression to AIDS. During this phase there is usually high levels of HIV viral replication where large numbers of viral particles spread throughout the body, seeding in various organs particularly lymphoid tissue like the lymph nodes, spleen and tonsils. The HIV RNA (genetic material) is extremely high during this acute phase and is ultimately the single strongest predictor for the rate of disease progression. HIV can be transmitted during this phase and there is evidence that the risk of transmission is higher during this time because the number of viral particles in blood and body fluids is so high.

This acute syndrome is so nonspecific and temporary, only 20 - 30 % of individuals with symptoms actually seek medical attention. As soon as a diagnosis of HIV is confirmed, it is highly recommended that a medication regimen begin. Dramatic effects have been seen when acutely infected patients were given HAART, highly active anti retroviral therapy. HAART typically consists of a protease inhibitor (Crixivan, Invirase, Norvir) and two reverse transcriptase inhibitors (Combivir, Epivir, Retrovir). Preliminary studies show that intervening as early as possible, while the immune system is still intact may have advantages. Patients may be able to control viral infection and minimize immune destruction.

If a person is at high risk or is exposed to HIV they should be tested. This will allow for early treatment and perhaps control of the infection.