D R . E L R O I


Friday, May 30, 2008

HIV Progression and Testing Part 4 - Tests

Testing for HIV Viral Load, Antibody Tests and CD4 Count Test

We can perform tests to test for the HI virus. There are three tests that can be used to determine how many viruses are present in blood and it is called the viral load. These are the PCR or Polymerase Chain Reaction, NASBA and Branched Chain tests. The tests are very expensive approximately per test. However, the tests for HIV antibodies are much cheaper and easier to perform.

There are three types of tests for HIV antibodies. They are the ELISA and Western Blot tests. Recently the newly developed Rapid test replaced the first two tests as a screening test for HIV. With a Rapid test, it is not necessary to draw blood which then needs to be sent to a pathology laboratory. A smear is taken from the inside of the mouth or a small sample of blood is taken after a finger prick. Using these samples, the test provides a positive or negative result within 20 minutes. Recent developments made these tests accurate and trustworthy.

It is very important to note that the tests used to determine if someone is infected with HIV are not testing for the HIV virus but for the antibodies that are formed as soon as the body detects the presence of the virus. If we therefore say someone is "HIV positive," it only means he tested positive for the presence of HIV specific antibodies. The limitations to this test are; it does not tell you when you were infected, how you were infected, what the viral load in your blood is and what your CD4 count is.

The period from the time a person is infected until the antibodies have been manufactured, is called the window period. During the window period there will be no antibodies present in the blood, and a person therefore tests negative even though the virus is already in the blood. Usually these antibodies form within 2-6 weeks, but sometimes it can take as long as 3 months.

Another test would be the CD4 count. This test does not test for HIV or HIV antibodies. It counts the number of CD4 cells in your blood and gives a good indication of how strong the immune system of a person is. This test is normally used to determine if a person is eligible to start with antiretroviral therapy or ARV. In most countries the protocol is to only put HIV positive people on ARV once their CD4 count is below 200.

According to my doctor, the protocol now including the Philippines is below 350 coz the side effects of the drug is much lesser. I have started my ARV last June 2007 because my CD4 count was 331.

If you want to get tested for HIV antibodies or HIV itself, you can visit San Lazaro Hospital in Manila. The HIV antibodies test costs around 400-450 pesos while the viral load test is around 6000 pesos. I would suggest the HIV antibodies test for it is much cheaper.

Note: Information was excerpt from the "Channels of Hope" facilitator's manual.

No comments: