How Is HIV Spread And How Is Its Detection Test Done?

Posted on Tue, 21 Jan 2014

Question: Dear Sir, I'd be really thankful if you could clear up my Confusion about 14 days, 28 days, 6 weeks and even 3 months waiting time after possible exposure to HIV AIDS-infection and before testing. Do we or don't we have to come back for another test after the 28 days DUO test?... Is the result of the 28 days DUO test conclusive and fully reliable? If payment for your response is required please do let me know how much and if possible via Pay Pal? Thanks a lot, Respectfully, XXXX

Answered by Dr. Roopa Hiremath (43 minutes later)

Brief Answer: HIV testing Detailed Answer: Hi Mr. Ton, Thanks for choosing health care magic for your query. I have gone through your query and I want to elaborate on HIV infection and HIV testing to help you understand better and also clear your confusion. HIV is spread most commonly by the sexual route (oral, vaginal, anal) The semen and vaginal fluid is very rich in HIV particles and these gain entry into the body through the mucosa covering the genitals during sexual intercourse. After entry, HIV reaches the local lymph nodes and multiplies there. After 4-11 days of exposure, the HIV gets spilled into the blood. So there is no test that can detect HIV within 4 days of exposure. After 4 days, HIV can be detected in blood. Antibodies against HIV take about 3 weeks to 12 weeks (21 days to 3 months) to develop. Coming to HIV testing, the most appropriate tests would be as follows: Early exposure: Within 2 weeks - PCR for HIV DNA/RNA and p24 antigen testing. 28 days after exposure: 28days duo test, ELISA for antibodies against HIV 1 and 2 are most reliable 90 days after exposure- Western blot test is confirmatory. Coming to the reliability of 28 day duo test - it is reliable as it is a combination test which tests for both antigen and antibodies of HIV. The strategy followed for HIV testing is that at least two tests using two different principles should show negative results consecutively to announce that person as HIV negative. So if you have undergone 28 day duo test and it is negative, I would suggest you undergo a confirmatory test like western blot to confirm the HIV negative status. I hope I have cleared your doubts. Please get back if any more clarifications. Thanks.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Roopa Hiremath (2 days later)

Dear Doctor XXXXXXX thanks a lot for your answers. 3 More questions if you will: You write : "Coming to the reliability of 28 day duo test - it is reliable as it is a combination test which tests for both antigen and antibodies of HIV." 1) If the 28 days DUO test is reliable how is it that in countries like Germany for example the official recommendation is still 3 MONTHS waiting time after exposure? 2) What is the official and scientific/medical PERCENTAGE of the 28 days DUO test reliability. Would you consider the 28 days DUO test conclusive? 3) Is the 28 days DUO test an OFFICIALLY recommended Standard by the WHO or other official health authorities worldwide? Thanks a lot for your reply. Respectfully, XXXX Dear Doctor XXXXXXX thanks a lot for your answers. 3 More questions if you will: You write : "Coming to the reliability of 28 day duo test - it is reliable as it is a combination test which tests for both antigen and antibodies of HIV." 1) If the 28 days DUO test is reliable how is it that in countries like Germany for example the official recommendation is still 3 MONTHS waiting time after exposure? 2) What is the official and scientific/medical PERCENTAGE of the 28 days DUO test reliability. Would you consider the 28 days DUO test conclusive? 3) Is the 28 days DUO test an OFFICIALLY recommended Standard by the WHO or other official health authorities worldwide? Thanks a lot for your reply. Respectfully, XXXX Dear Doctor XXXXXXX thanks a lot for your answers. 3 More questions if you will: You write : "Coming to the reliability of 28 day duo test - it is reliable as it is a combination test which tests for both antigen and antibodies of HIV." 1) If the 28 days DUO test is reliable how is it that in countries like Germany for example the official recommendation is still 3 MONTHS waiting time after exposure? 2) What is the official and scientific/medical PERCENTAGE of the 28 days DUO test reliability. Would you consider the 28 days DUO test conclusive? 3) Is the 28 days DUO test an OFFICIALLY recommended Standard by the WHO or other official health authorities worldwide? Thanks a lot for your reply. Respectfully, XXXX

Answered by Dr. Roopa Hiremath (3 hours later)

Brief Answer: HIV tests Detailed Answer: Hi Mr.Ton, Welcome back. I understand the concern regarding reliability of HIV tests, but the tests have to undergo vigorous rounds of quality control before getting released into the market as there are many social, moral and psychological issues involved with HIV testing. The answers to your queries are as follows: 1. 28 day duo test is a 4th generation test which detects antigens and antibodies against HIV and if a person is HIV positive he should test positive with this test. Some countries have 3 months waiting period for antibody testing because of window period in HIV. This period is the time required for antibodies to develop against HIV and varies from 3 weeks to 12 weeks. This is the period when a person can test negative for antibodies but still be HIV positive. Hence 100th day testing is recommended. 28 day duo test tests for p24 antigen and HIV antibodies. If the person is HIV positive and still in window period (meaning no antibodies) still he will show positive for p24 antigen by 28 day duo test. 2. The sensitivity of these two 4th generation test kits is proven to be 100%. Abbott Architect HIV Ag/Ab Combo Assay Bio-Rad GS HIV Combo Ag/Ab EIA 3. FDA(U.S Food and Drug Administration) has approved 4th generation kits as reliable in 2010. I hope I have cleared your doubts. Please get back if I can assist you further. Thanks.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Roopa Hiremath (5 days later)

Dear Dr. XXXXXXX happy and healthy 2014 for you! * To put it simple : would you recommend the 28 days DUO test to your best friends / family or not ? * The 28 day DUO test will ALWAYS show positive in the timespan of 28 days when a person is positive? * You write: "The sensitivity of these two 4th generation test kits is proven to be 100%. Abbott Architect HIV Ag/Ab Combo Assay Bio-Rad GS HIV Combo Ag/Ab EIA". ............are these tests IDENTICAL with 28 days, ONE MONTH DUO tests IN EUROPE? * A British homeopath by the name of XXXXXXX Chappell invented a homeopathic cure for Aids in Africa and India called PC1, claiming very encouraging healing-results. What is your opinion (perhaps aided by Vedic astrology) on the timeframe for a possible CURE for Aids? XXXX

Answered by Dr. Roopa Hiremath (4 hours later)

Brief Answer: 28 days duo tests used in Europe Detailed Answer: Hi Mr. Ton, Welcome back. Happy new year to you too. The answers to your queries are below: 1. I would definitely recommend the 28 day duo test to my friends and family as it cuts down the window period by 2 months and early detection helps in the initiation of treatment, counseling, and prevention interventions to reduce the risk of transmission of HIV. 2. This test if done correctly in a reliable lab should detect a person who is positive in 28 days after exposure. 3. Abbott Architect HIV Ag/Ab Combo Assay and Bio-Rad GS HIV Combo Ag/Ab EIA are available in Europe. 4. Possible cure for AIDS - I would not like to comment on homeopathic research and cure for AIDS as I am an allopathic doctor. Unfortunately, till now there is no cure for AIDS. However, there is vigorous research and various studies going on to develop an effective vaccine against HIV and this could be a major milestone in medical history. More than 30 candidate vaccines for HIV are under trial and hopefully an effective vaccine would come into existence soon. I hope I have answered all your queries satisfactorily. Thanks.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Roopa Hiremath (1 hour later)

Dear Dr. XXXXXXX thanks again. To sum it up: a student comes to me ( I am a teacher) saying they have had an exposure to HIV infection and I say "don't worry you just have to wait 28 days, after these 28 days have an HIV DUO test done and trust the result"... Would you agree? Thanks, these were my questions. XXXX

Answered by Dr. Roopa Hiremath (20 hours later)

Brief Answer: HIV diagnosis and counselling Detailed Answer: Hi Mr. Ton, Welcome back. I understand your concern regarding your students. Diagnosis of HIV/AIDS is not like other infectious diseases. A number of moral, ethical, legal and psychosocial issues are related with HIV positive status. So anyone who is assessing HIV status of an individual must be aware of these issues, strategies of HIV testing, protocol of testing, rationale of using test kits, counseling and informing the clients, importance of confidentiality and technical quality assurance. So I would suggest you guide them to a HIV testing and counseling center nearby and the doctor there will guide the individual accordingly based on his history of exposure. These centers also employ well trained counselors who will help relieve their anxiety and suggest appropriate HIV tests. Counseling plays a very important role in HIV diagnosis and it is recommended for the following individuals: 1. Persons already identified as having AIDS 2. Those being tested for HIV 3. Those seeking help because of past or current risk behavior 4. Those not seeking help but still practicing high risk behavior I hope I have cleared your doubts. Thanks.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Roopa Hiremath (19 minutes later)

Thanks again Doctor XXXXXXX but my practical question is this : is the 28 days or 1 Month DUO test conclusive in such a manner that I could recommend it to anyone? I mean, in the past we had to wait for 3 long months !! But now... can I safely recommend them to wait only 28 days = only 1 single Month...before having the DUO test done? I know it sounds silly but as the waiting period of 3 months is still in use in Germany for example ...... 28 days or 1 Month waiting time seems to be rather short. Thank you very much indeed for answering this very last question of mine in simple wordings. Respectfully, Ton.

Answered by Dr. Roopa Hiremath (14 minutes later)

Brief Answer: 28 day duo test is reliable Detailed Answer: Hi Mr. Ton, Welcome back. You can recommend 28 days duo test safely for HIV screening. As I have explained earlier, this test detects both p24 antigen and antibodies against HIV and is best done at 28 days after exposure. Thanks.

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Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar