What is HIV testing?
HIV testing is a simple blood test that helps to find out whether a person is infected by the human immunodeficiency virus. In some cases a saliva test may also be carried out. This virus can severely compromise the immune system of the infected person making him susceptible to deadly infections and cancer. This test assumes importance in the fight against spread of HIV as an infected person takes a lot of time to exhibit symptoms.
Why is it conducted?
- HIV testing is conducted for the timely detection and treatment of the affected person himself. This helps to prevent damage to the immune system or at least slow down the process considerably.
- As this infection eventually leads to AIDS, detection can help to reduce or delay full-blown development of this deadly disease.
- Besides this, people may often be infected without symptoms and may unknowingly spread the infection to others.
Who should go for it?
HIV is transmitted only through blood, semen as well as vaginal fluids and therefore can not be transmitted through casual contact.
People who are particularly at risk for infection are:
- People who have shared needles for injecting drugs are at an increased risk and should be tested once a year.
- People who have had sex without protection with more than one partner or an unknown partner.
- A man who has had sex with a man.
- Persons who suffer from any sexually transmitted disease (STD), tuberculosis, hepatitis, etc.
- Pregnant women are advised to have an HIV test as this infection can be transferred from mother to child. However, the risk of transfer can be remarkably reduced through treatment of the mother.
- Babies born to mothers with HIV infection.
The test that is conducted most commonly to check for HIV infection is the ELISA test. It is done after one month of infection and checks for antibodies. It is usual practice to carry out a second confirmatory test, if this test has a positive result.
The second confirmatory test is the Western blot test. This is normally advised when the first test comes positive.
The PCR test looks for genetic material of the virus and can even detect its presence when antibodies are not yet formed. However, this test tends to be expensive and will not be available at all HIV testing centers. This test is more accurate for newborn babies than the ELISA test.
Interpretation of results
It is important to note that there is a window period when a person may be infected with HIV and transmit infection to others. However, there may not be sufficient number of antibodies developed in his bloodstream to be detected by the HIV test. For this reason the test is carried out at a minimum of 30 days after there has been any chance of infection. Generally, an antibody test will give a clear indication at about 2-3 months after infection, though the newer tests may be conducted within one month with reasonable accuracy. It is advisable to go for HIV testing again after 3- 6 months of exposure to infection even if the test gave a negative result. This helps to rule out a late development of antibodies, which can occur in some cases.
Written by: Nandita tripati
Date last updated: January 07, 2015