What is the HIV Antibody Test?

There are several types of HIV antibody tests used today. All are highly accurate at detecting HIV antibodies (HIV antibodies are specific proteins made in response to an HIV infection). After infection with HIV, however, it can take up to 3 months for enough HIV antibodies to develop to be detected by the test.

A negative HIV antibody test result means that a person does not have detectable HIV antibodies at the time of the test. Since it can take up to 3 months after HIV infection for enough antibodies to develop, a negative test result is reliable only if the person has not had any sexual or needle-sharing risk behavior (or other exposure to infectious body fluids) during the 3 months prior to testing. Some people with recent risk behavior will test HIV antibody negative, yet may have actually been infected during the previous 3 months. These people will be highly contagious and may easily transmit HIV to their sex and needle-sharing partners. A high proportion of HIV transmission may occur when people are unaware of their infection. Finally, a negative test result does not mean that a person is safe from future HIV infection. People who test HIV antibody negative are urged to continue to follow HIV prevention guidelines to avoid becoming infected. People who continue risk behaviors are advised to re-test at least every 6 months.

A positive HIV antibody test result means that HIV antibodies are present because the virus is present - the person is infected with HIV (with the exception of newborn babies who are born with their mothers` antibodies). A positive test does not mean the person has AIDS, although many HIV-positive people may develop AIDS in the future. Anyone who tests HIV-positive can transmit the virus to others, regardless of how long they have been infected, whether they have AIDS or other symptoms, or whether their HIV infection is being treated with antiretroviral drugs. It is extremely important that HIV-positive people follow HIV prevention guidelines, not only to protect their partners from getting HIV infection, but also to protect themselves from other germs that could cause HIV/AIDS-related disease. People at increased risk of HIV infection should NEVER donate blood, plasma, or other organs, or go to such facilities to be tested.