Kindly advise whether HIV rapid tests cover O type antigen or not.

Hello,

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I have reviewed your query and here is my advise. As far as HIV (human immunodeficiency virus) infection is concerned, M strain variant of HIV1 is a common type. O subtype is very rare. However, let us move onto your question. Rapid diagnostic test and CMIA (Chemiluminescence Microparticle Immunoassay) usually detect M strain of HIV effectively. However, depending on manufacture, a final comment can be given. But RT PCR (real-time reverse transcription polymerase chain reaction) usually detects all strain for HIV. Kindly mention after how much time of exposure you have investigated with RT PCR? I am asking this question to rule out window period for HIV.

Hello,

Welcome back to icliniq.com.

I have reviewed your query and here is my advice for your case. RT PCR usually gives effective result after two to four weeks. So you had tested for it earlier. Moreover, CMIA and fourth generation ELISA also rule out HIV effectively after six weeks. But anyways, after three months of infection usually antibodies are developed in enough concentration and so rapid card test can effectively rule out HIV after three months. Now no need for doing PCR testing. It is used if you want to rule out HIV before six weeks. Now no need for PCR testing. The different kits use antigens that are prevalent in your area, and no need to focus only on O strain. However, advanced HIV CMIA test claims to detect O strain as well. You can investigate with CMIA test just now (after three months of exposure, repeat testing recommended). If it comes negative, then no need to worry and forget about incidence. Gp41 is present over HIV1 type virus and so can be present over subtype O strain as well. You can revert back with CMIA report once done to guide you further.