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HIV Testing

May 11, 2007

In some parts of the world where HIV infection rates are the highest, the one factor that seems to keep the HIV epidemic going strong is that many people don’t realize they are HIV infected. They in turn unknowingly infect others through unprotected sex. It’s obvious that one of the best ways to slow the HIV infection rate is to make sure people are aware of their HIV status by getting HIV tested. Let’s take a closer look at HIV testing.

There are three types of HIV testing in use today, each identifying a different substance present in the blood of those people infected with HIV.

The Antibody Test
The first type of HIV testing is an antibody test. Antibodies are proteins that are produced and released into the blood when a foreign invader such as a virus enters the body. These antibodies recognize and help the body’s immune system destroy the foreign entity. The HIV antibody test looks for the antibodies that are produced when HIV enters the blood stream. The presence of these HIV antibodies confirms that HIV infection has occurred. Another name for the HIV antibody test is an ELISA (Enzyme-Linked Immunosorbent Assay) test. Despite being a very effective test, the ELISA test can produce false positive results from time to time. Therefore if the ELISA test is positive the same sample is tested again using a second antibody test known as a Western Blot. The Western Blot is a more accurate test that produces far fewer false positive results. A positive Western Blot confirms an HIV infection.

The Antigen Test
The second type of HIV test is the antigen test. Antigens are foreign proteins, bacteria, or viruses that stimulates the body’s immune system to start producing antibodies. The antibodies in turn, will help destroy the antigen. The protein in HIV that causes the production of HIV antibodies is called the P24 protein. The HIV antigen test looks for the P24 protein in blood of people being tested for HIV. Its presence in the blood confirms that the person has been infected with HIV. The antigen test can identify an HIV infection sooner after HIV exposure than can the HIV antibody test.

The DNA Test
The third type of HIV test is the DNA test. DNA is the complex combination of proteins that contains all the genetic information for a living thing. The DNA is specific for each type of living thing. For instance, the DNA of a human is different than that of a rabbitt. The DNA is what makes a person a person and a rabbitt a rabbitt. The DNA test detects any genetic material that may be present in the blood. Finding HIV DNA in the blood confirms that HIV infection has occurred. Compared to the antibody and antigen tests, the DNA test can identify an HIV infection much sooner after exposure. In some cases, infection can be detected as soon as one week after exposure to the virus.

HIV Tests…Free vs. Anonymous
In most communities there are many places you can get an HIV test. Hospitals, HIV testing sites or local health departments usually offer HIV testing. There are two ways to have your test done.

Confidential Testing
Medical information, testing, and diagnostics are protected by confidentiality laws meaning the results can’t be shared with anyone without your permission. HIV confidential testing is no different. While the result of the test can’t be shared with anyone without your permission there are personal identifiers such as name, birth date, and social security number attached to the test. Rest assured that testing sites and medical facilities are bound by confidentiality rules meaning they would not hand out your test results to just anyone. Confidential tests are usually offered at medical facilities such as hospitals and have a fee attached that may or may not be covered by insurance.

Anonymous Testing
Because there is so much stigma and prejudices attached to HIV, testing sites offer anonymous testing. There is no name or other identifying information attached to the test or linking a test result to a specific person. Instead, the testing site assigns a unique identifier such as a number or combination of numbers and letters. There is no name or other personal identifiers attached to the test meaning there is no way anyone can link a positive test to a specific person. Anonymous tests are usually offered at HIV testing sites or local health departments and are most often free of charge.

How is the HIV Test Done?
Getting an HIV test is a very simple procedure. Normally, a small sample of blood is taken from the arm and sent to the lab. Once in the lab, the blood is tested using one of the three types of testing we talked about earlier. Depending on the lab and the type of test being done, the results can take anywhere from three days to a couple weeks. An alternative means of acquiring a sample for testing is by way of an oral swab. The inside of the mouth is swabbed with a cotton applicator. Cells from the inside of the mouth accumulate on the swab. These cells are sent to the lab for antibody testing similar to the testing done on a blood sample. A third means of testing is not commonly used but is available to those reluctant to getting a blood sample drawn. Urine samples can also be tested using the ELISA and Western Blot antibody tests however it is not nearly as accurate as testing a blood sample.

Waiting for an HIV test result can be brutal. However, in some circumstances, getting an HIV test result can’t wait. There is a rapid HIV test that can produce results in a matter of minutes instead of days. Rapid HIV tests are antibody tests using ELISA and the confirmatory Western Blot. They are considered to be just as accurate as blood tests.

Home Test Kits
There is some debate about the accuracy and benefit of home testing. Actually it is more of a home collection kit. A small drop of blood is placed on a card and then sent to a licensed lab for testing. A unique number identifier is assigned that allows for the user to get results over the telephone. There are benefits and risks with home tests. They include:

Benefits
• The very private nature of home testing could encourage more people to get tested.
• Home testing empowers users with regard to their healthcare decisions.
• Home testing can increase early diagnosis of HIV which leads to earlier access to HIV care.

Potential Risks
• Incorrect or inappropriate use of the test can lead to inaccurate results.
• Using the home test too soon after exposure can cause a false negative result and a false sense of
security. This, in turn, could result in continued high risk sexual behavior.
• Home testing does not provide pre and post test counseling. Without the counseling that normally
accompanies an HIV test, there is a potential for very adverse emotional issues if the test happens to
be positive. In addition, counseling helps change at risk behavior decreasing the probability of Hiv
infection.
• In the event of a positive test, follow-up and partner notification could be delayed.
• The cost of the home test kit may be prohibitive for those populations that need the test most.
• Home testing could interfere with state and federal HIV reporting requirements.

When Should You Be Tested?
The Centers for Disease Control (CDC) is now recommending that HIV testing be part of routine health screenings and health maintenance. But in the event of a potential exposure to HIV, a series of HIV tests should be done to confirm that HIV infection has not occurred. But why a series of tests? Isn’t one test good enough?
When HIV infection occurs, the body immediately begins producing HIV antibodies. However, the body takes anywhere from 20 days to 6 months after exposure to HIV to produce enough antibodies to be detected by the HIV test. Which means if you are HIV tested before there are enough detectable antibodies, your test will have a negative result even though you have been infected. For this reason after a potential HIV exposure, a series of tests should be done to confirm there has been no infection.
The series of tests include:
• The first test should be done soon after the suspected exposure has occurred.
• A second test 6 weeks after the exposure.
• A third test 3 months after exposure.
• And finally, a fourth test 6 months after exposure.
If all those tests are negative, then there has been no HIV infection. Keep in mind that if another potential HIV exposure occurs anytime during the testing series, the series must be started over.

What Happens if I My Test is Negative?
A negative HIV test is very good news. A negative test is your opportunity to examine what led to your exposure and ways to avoid exposure in the future. That may mean that safer sex methods such as condoms becomes a part of your sexual choices. It may mean that you no longer share needles while injecting drugs or better yet you get help for a drug problem. And if there was no exposure and you were just getting tested to learn your status, now you know.

What Happens if My Test is Positive?
If your HIV test is positive, the first thing to do is take a deep breath and try not to panic. To stay healthy you need to take the next step. That step is getting into HIV care with a qualified HIV specialist. An HIV positive diagnosis will change your life but unlike 25 years ago, you can live a long healthy life with an HIV diagnosis.
Don’t let the possibility of a positive diagnosis prevent you from getting HIV tested. Get the test. If it is positive, get into care as soon as possible and you will live a long healthy life. If it’s negative, you know your status and can take the proper precautions to stay that way.

Posted at 03:27 PM by Mark Cichocki in the HIV & AIDS category/ies.