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Got an ache or pain? Have a question about a prescription or over-the-counter drug? Looking for some FREE medical advice?
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Question:
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| Dear Doctor, This is regarding your reply to my previous question. You were stating that window period of minimum 3 months has to be waited before taking a HIV ELISA. In the literature there is strong consensus that a DNA PCR should turn positive within 1 month of infecton. Is there any place in Moscow where I can take reliable(Abott etc..) DNA or RNA PCR or a fourth generation ELISA(screening for antibodies plus P24 antigen)please? Also is it possible get confidential testing or some home kits etc...? Thank you in advance.
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Answer:
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| Thank you for your inquiry. Given the e-mail and phone-in interest that the original question led to, perhaps it's worth going over the issues in detail. Caution: if anyone reading this thinks they are or could be at risk of HIV infection, PLEASE discuss the risk assessment and testing issues face to face with your doctor soonest. You are quite right that DNA PCR "should" turn positive within 1 month. However there are (as frequently in medicine) some caveats; some significant, others less so. 1) the DNA PCR negative period is IMO not the same as the recommended period of waiting to be very sure that one will not develop antibodies, so as to enable one to feel fully justified in re-commencing unprotected sex in a relationship or indeed episodically. (BTW this is a public health comment not a moral comment). 2) Elisa is the test still most often used for screening (expect this to change over time). FYI DNA PCR test is not FDA approved for diagnosis (if this matters to the readership: we mention it as it is a question often asked). If the Elisa is positive, Western blot is next done for confirmation. (If the WB does not confirm, the Elisa result was 'false positive'). Even if aysmptomatic but worried, an initial Elisa test can of course be done earlier than 3 months but the result thereof may not be able to be used for self and other's close-to-100%-reassurance. If symptomatic and / or at high risk one should not wait 3 months, sorry I should have put more emphasis on this in previous replies. 3) A negative Elisa test at 3 months is usually stated as being close to 100% 'reliable' as a screen (no immunological test ever devised can be 100% reliable in every case in my opinion). This is the basis on which a 3 month window period is advised - because if the first Elisa screen is negative one does not usually go on to a Western blot or DNA PCR... but if the risk assessment was persuasive, many would recommend the 3 month re-test for a) peace of mind and b) see answer 1) above. 4) However, if one does want to use / rely on a DNA PCR for the initial screen, at 1 month after exposure DNA PCR is definitely more sensitive (in that the chance that a DNA PCR would be falsely negative is both very small - opinions differ, but probably less than 1%, and less than the chance that an Elisa would be falsely negative). And many believe that PCR at 4 weeks is as diagnostic as Elisa at 3 months... Warning: Marketing Comment Ahead: DNA PCR can be organized through a consultation at the SOS clinic. There are no home HIV kits available in Moscow that we know of, but if anyone has any knowledge to the contrary please post. Confidentiality everywhere in the world is relative in that local health laws and regulations can override the confidentiality of the doctor-patient relationship. So, for example, the health authorities in Moscow and the CIS require that all positive HIV tests be reported to the Central Epidemiological Institute. HIV testing is a difficult area to discuss, so comments are welcome. Hope this helps.
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