by Jay Vithalani
Getting tested for HIV is never easy. Some people hate needles. Some people are so terrified at the prospect of a “positive” result that they refuse to get tested. Others justify their “test abstinence” by adopting a fatalistic attitude: what good will it do to know my HIV status given that I can do nothing about it? There are also some misconceptions about HIV testing, for instance that the tests are expensive and unreliable.
I want to respond to some of these fears and clear some misconceptions in this brief article. Outlined here are some fundamentals of HIV testing, along with some reasons for getting tested if you are sexually active. Some of the material may seem painfully elementary to the initiated, while a small portion may be a little technical. The aim has been to be comprehensive and as jargon-free as possible. There is also a paragraph about PEP, or post-exposure prophylaxis. Finally, there is a list of testing centres in Mumbai, with basic contact information.
~~~~~~~~~~~~~~ I. Facts and Vocabulary
(1) HIV: The acronym stands for Human Immunodefiency Virus, the virus which causes AIDS (Acquired ImmunoDefiency Syndrome). HIV is a relatively difficult virus to contract (Hepatitis B, for instance, is ten times more infectious). HIV works by destroying the body’s natural immune system, thus leaving the body vulnerable to a host of infections. Not everyone who is HIV-positive has AIDS. A person has AIDS only when the body’s immunity falls below a certain level. There are many millions of people who are HIV-positive who don’t have AIDS, thanks largely to drugs developed over the last 20 years. While there have been great advances in the treatment of HIV and AIDS in the last decade, no current treatment eliminates the virus from the body or cures AIDS.
(2) Antibodies: These are cells produced by the body in response to a particular infection. The human body can deal with many mild infections. Thanks to our antibodies, we have either a resistance to or the capacity to deal with infections like the common cold.
(3) Antigens: These are the little things which cause infection, usually a virus or a bacterium.
(4) ELISA: This stands for Enzyme Linked ImmunoAssay, which is quite a mouthful and not in a good way. It’s a very common test procedure in labs. The ELISA test for HIV/AIDS is the standard screening test used to determine whether or not a person is HIV-positive. The ELISA doesn’t detect the virus itself but rather the antibodies the body produces in response to HIV. It is cheap, easy for labs to perform, and extremely accurate (greater than 99%).
(5) Western Blot: This is a much more complicated test than ELISA, used only to confirm a positive ELISA result. It, too, tests for antibodies and not the antigen itself. The Western Blot is not a screening test but a confirmatory test. It is many times more expensive than the ELISA. A person getting routinely tested should almost never get a Western Blot; ELISA is generally accepted as the best first-line test.
(6) Seroconversion: If HIV enters the body, the immune system produces antibodies in response. Seroconversion is the process by which a previously negative person becomes HIV-positive (serum being a big component of blood). Even if HIV has entered the body, a person isn’t technically HIV-positive until antibodies in response to the virus have been produced. The time it takes people to seroconvert varies greatly between individuals. Some people seroconvert (produce antibodies) in a few days, some people take much longer. About 50% seroconvert within 25 days of exposure to HIV. Over 99% seroconvert within 90 days. There have been very rare and isolated cases of seroconversion taking longer than three months.
(7) Window period: Since the ELISA test looks for antibodies rather than the virus itself, you can’t get tested just one hour after a potential exposure. Antibodies can take up to 90 days to appear. After a potential exposure, you should wait for three months before getting tested. A test prior to that wouldn’t be considered accurate, since the virus may be in your body but your body may not have produced antibodies to it. This 90-day period is known as the window period.
(8) Test accuracy (sensitivity and specificity): Both the ELISA and the Western Blot are highly accurate tests. That is to say, in testing jargon, they are both sensitive and specific. For complex reasons, though, high specificity in a test usually comes at the expense of some sensitivity and vice versa. It’s possible to illustrate these two concepts with a simple example. Imagine a bag filled with 1,000 marbles. Most of the marbles are white, let’s say 990 of them. Three marbles are red and seven are yellow. Now, I want to design a test which will detect the presence of the red marbles in the bag. If we say that the red marbles are antibodies to HIV produced by the body and the yellow marbles are antibodies (or other agents) unrelated to HIV, then both the ELISA and Western Blot are extremely good at detecting the red marbles in a crowded bag. Yet, there is a difference between them. ELISA is a highly sensitive test – it is possible, in a very small minority of cases, that it will detect a yellow marble and mistake it for a red one. This is why a positive ELISA has to be confirmed with the Western Blot. The WB is an extremely specific test. It can detect only red marbles. It is theoretically possible, in a vanishing small percentage, that it might “miss” the red marbles, but it will never mistake a yellow (non-HIV) marble for a red (HIV) one. That’s why, for a positive test result, the two tests are used in conjunction.
(9) False positive, false negative: After having said that the tests are extremely accurate (sensitive and specific), every test designed has a certain (very small) degree of fallibility inherent in it. A false positive result is one in which the person tests positive but is in fact negative. This happens in a very small proportion of ELISA tests; in our example above, in the case of a false positive result, the test has mistaken a yellow marble for a red one. So the Western Blot is carried out, which would reveal that the person was in fact negative. A false negative result, on the other hand, is one in which a person is actually positive but the test result comes back as negative. This is most often due to testing having taken place during the window period, before antibodies to HIV have developed.
(10) Rapid testing: The time it takes for ELISA results to come back from the lab varies from same-day results (at some labs, if you go bright and early) to a week or more. Of course, this waiting period can be a time of anxiety and stress. (Some people don’t even go to pick up their results.) Recently, tests have been developed which return a result in 15 to 30 minutes and which perform at ELISA-like accuracy. These rapid tests are now available in large Indian cities like Delhi and Mumbai. Newer versions of the rapid test, available abroad, can even be performed using saliva rather than blood. (In a positive person, saliva has a very low concentration of HIV, enough for detection but not transmission.) It should be added that rapid tests are also antibody tests, like the conventional ELISA and Western Blot, and so the 90-day window period applies to them as well. And if a result comes back positive, it should be confirmed, as always, with the Western Blot.
(11) Other tests: There are tests available which detect the presence of the antigen (virus) rather than the antibodies. The best-known of these is a family of tests using a technique called PCR. They are pretty expensive and technically very complex. But they seem to offer one clear advantage over the antibody tests: since they are looking for the virus itself, with PCR tests you don’t have to bother with the wait and anxiety of the window period. However, the disadvantages of using PCR testing as a first or diagnostic tool are many. First, even with PCR, it is recommended that you wait 28 days after a potential exposure to get the test, since it can take that long for the virus to reach detectable levels in blood. Second, given the complexity of the testing method, PCR tests are more prone to lab error. Third, PCR tests are so sensitive (see above) that they have a much higher rate of false positives than antibody tests. Fourth, they are not considered as definitive diagnostic tools (in other words, a negative or a positive result would have to confirmed at a later date by the conventional antibody tests). Fifth, the expense.
(12) Anonymous vs confidential testing: A confidential test is one in which a lab performs the test for an individual (under his or her name) but doesn’t disclose the test results to anyone other than the person tested or without his/her consent. In an anonymous test, no names are used. The person tested is assigned a number at the time the test is performed. To pick up the results, you present the slip with that number. Obviously, anonymous tests offer a greater measure of privacy than confidential tests. If you’re worried about using your name for a test, you should opt for anonymous testing. Many private labs, however, will perform HIV testing only with a doctor’s prescription.
(13) Counselling: In an ideal testing situation, you would be counselled by a trained person both before the test is performed and after you receive the result (whether the result is positive or negative). Why is counselling important? Well, for one, HIV testing can be a stressful event and a trained counsellor can help you understand and relieve the stress. Second, pre- and post-test counselling is a good time for you to review your safer sex practices with someone who can answer questions and allay doubts. Third, if the test result is positive, a counsellor can speak to you specifically about living with HIV, and if the result is negative, he or she can can help you go over your commitment to remaining so.
II. Why Get Tested?
So you’re thinking of getting an HIV test but still have some doubts. Should you go to that dreaded lab or not? Here are some thoughts on why getting tested is probably a good idea.
(1) If you’re one of the “Worried Well” – the many, many people who are anxious about their HIV status, regardless of their sexual history or risk – then getting a test is a good idea. Your negative status will be confirmed and you can carry on with your life, or obsess about something else.
(2) Knowledge is power. Knowing your status can help you make informed decisions. If you are in fact positive, knowing your status early can be vital in making treatment decisions; this is borne out by both common sense and studies which show that the later that HIV infection is diagnosed, the worse the prognosis. If you have a sexual partner or partners, knowing your status can also help you make decisions about safer sex.
(3) “Why should I get tested when there’s nothing I can do?” The answer to that is: HIV and AIDS are serious conditions, there is of course no doubt of that. But there are two common misconceptions: First, that HIV=AIDS, which is not the case, and second, that being infected with HIV is an automatic death sentence, which it is not. Drug therapy is becoming increasingly available and affordable, and has helped literally millions of people around the world live more or less normal lives with their HIV infection. And many people don’t need antiretroviral therapy for many years after being diagnosed with HIV. Also, new drugs therapies are being developed every year. It is hoped that, within the next decade or two, HIV will become a chronic but manageable condition, like heart disease or diabetes. Giving up hope is not the answer.
(4) Making an annual HIV test part of your routine medical check-up – like an annual mammogram for women over 40 or a periodic blood-pressure check for all businessmen – may be less stressful than going for a test every time you’re irrationally anxious or think you’ve had potentially unsafe sex. While it becomes part of your annual routine, it can also serve as a kind of “reality check”: a reminder that you’re relieved that you’re (probably) negative, that you will remain so, while continuing to enjoy (safer) sex.
III. PEP – post-exposure prophylaxis
This stands for post-exposure prophylaxis (which is a fancy word for prevention). If someone has potentially been exposed to HIV, either in a healthcare setting (a doctor getting an accidental prick from a needle which has been used on a positive patient) or sexually (receptive anal sex, for example, with a person of unknown status) – in both of these situations, PEP can drastically reduce the chances of being infected with HIV. The exposed person takes a course of antiretroviral drugs for 28 days (usually a combination of AZT and 3TC), with the preventive therapy beginning within 72 hours of the exposure. The sooner the therapy is started after the exposure event the more effective it is thought to be. Basically, PEP works by eliminating HIV before it can establish itself in the body. It is sometimes called the “morning after” pill for HIV. Except that the PEP course is 28 days and needs to be followed by the usual tests 90 days or more after exposure. The cost and possible side-effects of the drugs (and probably the psychological trauma as well) mean that PEP is not a blank cheque given to irresponsible barebackers. Used wisely, PEP can be can effective tool in reducing the incidence of HIV.
IV. Testing CentresThere are a number of centres where the test can be done, at costs ranging from nothing to around Rs750/-. This is one case where more money does not necessarily imply better service. Many of the best services, with excellent technical facilities and proper pre-test counselling, and post-test counselling (if the person tests positive) are in the free or low-cost testing centres operated by the government and NGOs.
But these may not be convenient for everyone to access, in which case one can go to the more reputed private centres – but with a cost and no counselling.
(1) Humsafar Center – If you’re looking for a gay-sensitive place for testing, the obvious place is the Humsafar centre in Vile Parle (East), which now does testing six days a week. Earlier the reports had to be collected from Sion Hospital, but now everything is done at the centre. Humsafar now also has counsellors working in five large public hospitals across the city, so one can go to these places for testing and specifically contact these counsellors (on specific days of the week):Humsafar Centre, Vile Parle (East) – 26673800/26650547, ask for Mr.Murgesh, 6 days a week, 4.00 p.m. to 8 p.m.
Other centres with Humsafar counsellors: Borivili: Bhagwati Hospital – contact Mr.Ashok, 9833239249Ghatkopar: Rajawadi Hospital – contact Mr.Shashi, 9892838163, Mon/Tues/WedJuhu: Cooper Hospital – contact Mr.Shyam, 9892822150, Tues/Thurs/Sat
Parel: KEM Hospital – contact Mr.Sandeep, 9819386511, Mon/Wed/FriSion: Sion Hospital – contact Mr.Harish, 9870457574, all days
(2) Saadhan Centres – these are run by Population Services International, a NGO which also ensures that its staff is fully gay-sensitised and gives excellent all round counselling. It uses the rapid test which means you will get the results in one hour. Saadhan has a single helpline which can be called for all details – 2389-2222.
Clinic locations are: Saadhan Clinic-Vashi (Mobile Van), Vashi Truck Terminus, Sector 19, Opp Jhunkha Bhakar kendra, Vashi. M-F 10 am – 6 pm.Saadhan Clinic-Kamathipura, Mumbai- A/50, 7th Lane, Close to jayshree masala centre, Kamathipura, Mumbai 400008. M-F 10 am – 6 pm.Saadhan Clinic-Cotton Green, Mumbai-1st Floor, Opp Ram Mandir, Air Force Station, Cotton Green, Mumbai 400 033. M-F 10 am – 6 pm.
(3) Dr.Amin’s Pathology Laboratory, Tulsiani Chambers, Nariman Point – no counselling, it costs Rs450/- and you have to go by 2.00 p.m. to get the report by 5.30 p.m. the same day. The advantage is that it’s easily accessible for many people in Nariman Point and they will not require a referral from a doctor – you can just walk in. Tel: 22825230 / 22822471 / 22822472 / 22884262