HIV Seroconversion - Definition

What Does It Mean to be HIV-Positive or HIV-Negative?

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Definition:  Seroconversion is a term used to describe the development of antibodies to a particular antigen (infectious organism). When a person develop antibodies to a virus like HIV, they are said to "seroconvert" from antibody-negative to antibody-positive state.

Seroconversion takes place when an antibody test can confirm that an infection has occurred. This requires that enough antibodies be produced, the process of which can take from as little as a week to several months after an exposure.

Prior to this, a test may return either a false negative or inconclusive result. This period of uncertainty is called the window period. Testing within this time frame may lead a person to think that he or she is sero-negative when, in fact, an infection has taken place.

Once a person is sero-positive (meaning that there is confirmation of HIV antibodies) then that person will be sero-positive for life. Even if a person is placed on antiretroviral therapy and achieves a so-called undetectable viral load, the virus is not eradicated from that person's system. "Undetectable" simply implies that there is no evidence of viral RNA in the person's blood.

Symptoms of HIV Seroconversion

A person who is seroconverting can sometimes exhibit symptoms of illness. This can be referred to as seroconversion illness, acute seroconversion, acute HIV syndrome, or acute retroviral syndrome (ARS).

ARS can occur in anywhere from 30% to 50% of newly infected persons and present with flu- or mononucleosis-like symptoms.

During the initial (acute) period of infection, HIV replication is very rapid. As the level of circulating HIV increase, it begins to attack the immune system by infecting the very cells associated with the immune response.

Because of its similarity to the flu or mononucleosis, ARS is often missed during diagnosis.

The most common symptoms include:

  • Fever
  • Fatigue
  • Headache
  • Sore throat
  • Muscular aches and pain
  • Joint pain
  • Swollen lymph glands

While testing too early can return an inaccurate, false result, some newer combination HIV tests are able to detect up to 75% of acute infections, allowing for early treatment, better viral control, and earlier resolution of symptoms.

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Cohen, M.; Gay, C.; Busch, P.; and Hecht, F. "The Detection of Acute HIV Infection." The Journal of Infectious Diseases.2010; 202(Supplement 2):S270-S277.

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