A standard antibody test does not look directly for HIV. Rather, it checks for antibodies -- proteins your body makes in response to having HIV. If you have these antibodies, you are considered to be HIV-positive. That means you have HIV, the virus that causes AIDS.
If your result comes back positive, some people take a second test to confirm the result. For some, taking another test eases their doubts about the result. However, labs normally test your blood two different ways to confirm a positive result. So, when you get a positive test result, your blood or saliva has already been tested twice.
If you do not have these antibodies, you are considered HIV-negative. However, it can take up to six months after you've been exposed to HIV for you to develop antibodies. If you test negative, then you should screen again three months and again at six months after the exposure to confirm that you're HIV-negative. You won't know for certain if you are negative until you confirm it with another test after 6 months from the original exposure.
In some cases, the test result may come back indeterminate. Usually this occurs when the test is taken too early after the exposure. When this happens, you should repeat the test awhile later. Rarely, it can take several months before the test gives a definitive answer.
The standard antibody test, however, is not used for newborn babies. It is not reliable in detecting if a baby -- born to an HIV-positive woman -- is infected with HIV. In this case, babies are born with their mother's antibodies, so special tests must be used to tell if a baby is infected.
Depending on where you live, you may have several screening options available to you. It's important that you think about and choose the one that's right for you. HIV screening will be part of your first nPEP visit. You doctor may have rapid testing available, and thus be able to get immediate results. These results can only tell you if you have HIV from a previous exposure. They cannot tell you if you've recently been exposed to HIV and if that has lead to an established HIV infection. The basic HIV screening options are explained below. Other options may be available to you through your doctor or site where you are getting nPEP services.
The benefit of going to your doctor is that you may already have a good relationship and feel at ease talking to her or him about HIV. The drawback is that he or she may not be well trained in providing counseling before and after testing. A well-trained counselor can help answer questions you might have about HIV and can often provide you with referrals to local resources.
These sites usually provide counseling free of charge along with the screening. You could then talk one-on-one with the counselor who can answer the questions you might have. They usually can refer you to HIV prevention resources in your area and provide you with emotional support. And, if you do test positive, they can help you cope with the news and direct you to local resources for more support. Some sites use standard blood draws or saliva swabs, where results are often available in a week or two after being sent to a lab and processed. Some sites have saliva-based rapid tests available (called OraQuick). These test results may be read in about 20 minutes.
www.homeaccess.com) and at many drug stores, but it's not available in every state.
The kit includes a booklet that discusses and answers some questions about HIV screening. It also contains a needle, a small blotter pad and a postage-paid envelope. You will also find a unique ID code that you must keep in order to get your results.
To use the kit, prick your finger with the needle and put a few drops of blood on the blotter pad, as directed. Mail the blotter pad in the postage-paid envelope. The booklet gives you a toll-free phone number to call for your results.
When you call, an automated machine will ask you to enter your ID code. After you do, you will be passed to a counselor who will explain your test results and answer your questions. Over the phone, the counselor can give you a list of referrals for HIV prevention or other services in your area. If you want, they often can link you directly by phone to them.
The kit costs in the $45-60 range (depending on how quickly you request your results). But before you choose to test this way, consider how you feel about being counseled over the phone, how you feel about getting information about your HIV status over the phone, and whether you may benefit more from face-to-face counseling.
Several in-home HIV test kits are advertised on the internet. Only one is approved by the FDA. That is the Home Access Express HIV-1 Test System, made by Home Access Health Corporation. Other tests are not proven reliable and should be avoided. The FDA offers the warning below to consumers about other HIV testing options.
The advertisers of the unapproved HIV home test kits claim that the presence of a visual indicator, such as a red dot, within 5-15 minutes of taking the test shows a positive result for HIV infection. These unapproved test kits use a simple finger prick process for home blood collection or a special sponge device for saliva collection. The blood or saliva sample is then added to a plastic testing device containing a special type of paper. A developing solution is added to determine if the sample is positive for HIV. The samples are not sent to a laboratory for professional analysis. Although this approach may seem faster and simpler, it may provide a less accurate result than can be achieved using an approved test, which is analyzed under more controlled conditions than is possible in the home.
These tests are not routinely used to check for HIV infection. First, they cost a lot more than antibody tests. Second, a number of problems occur when using them to screen for the presence of HIV. The major problem is that they have a significant false positive rate. That means the test sometimes suggests that someone is infected when in fact they are not. Using these tests to screen for HIV has caused people emotional unrest. As well, antibody tests are more than 99.9% accurate.