Testing: The basics
Many places provide private and confidential testing for HIV – both within the public and the private sector, for example:
- Doctor’s rooms.
- Community health centres.
- Family planning clinics.
- Sexually transmitted disease clinics.
Most of these places provide free or inexpensive HIV testing. It is important to get tested at a place that also has HIV and AIDS counselling. Counsellors are often able to answer questions and assist the individual in understanding what the test results mean, and what action can be taken going forward.
How HIV tests work
The HIV test detects the body’s response to HIV infection, by reacting with any antibodies that may have been produced in response to HIV infection. That means that the test does not detect the virus itself. Antibodies are special cells your body creates to fight infection. After acquiring HIV, most people develop antibodies that can be seen within 3 months (the average time is 25 days after exposure to HIV). In rare cases, it can take up to 6 months to be able to see HIV antibodies. As a result of this delay, an individual should get tested 6 months after their most recent possible exposure to HIV. If an individual has a test that is negative, then it should be repeated 3 months later in case the person was in the ‘window period’ (the period during which the body may be producing antibodies to HIV).
Types of HIV tests
Rapid tests are becoming increasingly popular in Africa. They are highly reliable (over 99% accuracy), cost-effective, and give the result within a short period of time (normally within half an hour). The patient may also be able to see the kit and the result. Either a small sample of blood (from a prick on the finger) or sample of mucus from the inside of the cheek or gums is taken, depending on the test. Should the test be positive, a confirmatory test would usually be carried out. The confirmation is done using either a different rapid test or via a blood sample taken to carry out an ELISA (enzyme-linked immunoassay) test.
The ELISA test was the standard used by many clinics before the advent of the rapid test. The patient’s blood is sent to a laboratory in a plain tube. Two separate specimens are tested using two different kits to confirm patient identity. The test result is not immediate and results may take several days before the patient is given the results. This often places stress on the patient. In the event of a positive result, a confirmatory test is also done as with the rapid test above.