INFORMATION  ON HIV

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Stages:

HIV Overview   Natural History

HIV infection results in a chronic,  progressive illness. Its course is marked by increasing levels of viral replication  and the emergence of more virulent viral strains. This process causes the  destruction of the immune system. HIV infection is "staged" by CD4 cell counts  and clinical symptoms. Not all people progress through all "stages" and the  time frames may also vary greatly from person to person.

 

Seroconversion

After infection with HIV, there  is usually a seroconversion illness followed by an asymptomatic stage which  lasts months to years (up to 18, but 10 years is the average). This is followed  by symptomatic phases which correlate with progressive immunodeficiency.

 

Progression of HIV

The progression of HIV disease  varies from person to person and depends on a number of factors including  genetics and mode of transmission. Viral load is an important surrogate  marker which measures the quantity of virus in plasma and predicts the rate  of progression. It is a measured in RNA copies/ml. It is also used to assess  response to drug therapy and may predict the development of drug resistance.  After seroconversion, each person develops a viral load set point. The lower  the viral load the slower the progression of HIV disease (i.e. immune system  destruction) and eventually clinical symptoms and opportunistic conditions.

Transmission Routes of HIV

 

Acute Primary HIV Infection

Acute Seroconversion Illness

Between 50-90% of people  infected with HIV have an acute clinical illness which typically occurs 2-4  weeks after the infecting exposure to HIV. Very often these seroconversion  illnesses are recognized in retrospect since the symptoms may be non specific  (viral or flu-like). Many develop a mononucleosis-like illness which begins  acutely and lasts up to two weeks. Symptoms may include: fever, headache,  lymphadenopathy, myalgia, rash, and mucocutaneous ulceration.

 When a seroconversion illness  is detected, most clinicians would begin antiretroviral therapy.

 Laboratory tests may indicate  a viral infection. HIV p24 antigen may be detected at this stage even if  antibodies to the HIV have not yet formed. Viral load is very high at this  stage and CD4 counts drop transiently during seroconversion.

 

Natural History of HIV-1 Infection

 The progression of HIV  disease can be divided up into the following stages: 

The conditions seen in HIV disease have been dramatically altered by the highly active antiretroviral therapies. Many opportunistic conditions are now seen much less frequently.