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How Soon Is PCR Test Advisable After Intercourse?

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Posted on Tue, 16 Aug 2016
Question: Hello Doctor..... Can you mention to me the best time to apply PCR test after sexual intercourse? I know that the virus can be detected after 11 days of exposure. giving more days would be better to get 100% result without mistakes? for example 30 days and above.The same story to Hepatitis, i heard i need to be wait for 21 days before applying PCR test .... hope you give me the best time to apply PCR test for STDs . The more i wait the more accurate results i get in case of PCR test? thanks
doctor
Answered by Dr. Bharatesh Devendra Basti (1 hour later)
Brief Answer:
HIV RNA PCR sensitive after 10-14 days exposure

Detailed Answer:
Hi
Thank you for query. I am Dr Bharatesh D Basti answering your query.
Welcome back to health care magic.

HIV 1&2 RNA PCR test is very sensitive (99%) after 10-14 days after exposure. It remains positive for life unless treated by anti-HIV drugs or immunosuppressive drugs or affected by immunosuppressive disease. The test is good after 10 - 14 days exposure.
HIV 1&2 antibodies can appear 2-6 weeks after exposure latest by 3 months. They are considered conclusive after 3 months.They remain positive forever too.

Hepatitis B PCR can be positive after 21-30 days exposure. But it's levels come down later as the bodies immune system takes over and antibodies appear. It is difficult to have conclusive results with this test if negative results.
Later only the HbSAg(antigen) or the antibodies can be detectable.So HBSAg or antibodies to hepatitis B tests are also done to have conclusive results.

You can get back for any clarification.
Thank you
Dr Bharatesh D Basti
Dermatologist and venereolgist
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
doctor
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Follow up: Dr. Bharatesh Devendra Basti (16 minutes later)
Thanks doctor. I am planning to do PCR test for HIV , Hepatitis , HPV 18,16,12 ( after 32 days exactly of the sexual intercourse, is that good? If the outcome result was negative for all of the above diseases that means the result will not change after 3 months and 6 months? Thanks .
doctor
Answered by Dr. Bharatesh Devendra Basti (39 minutes later)
Brief Answer:
HIV/hepatitis B it is helpful

Detailed Answer:
Hi
Thank you for follow up query.

It will be very helpful for HIV and Hepatitis B after 30 days. These tests are unlikely to come positive later after 3 or 6 months.
HPV in males is not really done and required. You can get it done as a baseline. These also does not vary after 3/6 months.

You can get back for any clarification.
Thank you
Dr Bharatesh D Basti
Above answer was peer-reviewed by : Dr. Prasad
doctor
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Follow up: Dr. Bharatesh Devendra Basti (33 minutes later)
Thanks again doctor.... I read on CDC website that the window period of HIV is between 10 to 28 days if u want to make a test via PCR , so if did a test after day 40th the result will not be accurate? The test is only reliable when we check between 10 to 28 days only? After that i should not do PCR?
doctor
Answered by Dr. Bharatesh Devendra Basti (27 minutes later)
Brief Answer:
HIV PCR will be positive later too.

Detailed Answer:
Hi
Thank you for follow up query.

HIV RNA PCR can detect as early as 10-28 days post exposure. This is the best test during this period.
This detects HIV RNA material. This remains positive later .These counts reduces if treated with antiretroviral drugs or immunosuppressive drugs. They are usually not used as diagnostic tests though it is helpful. It is used to monitor treatment to see whether there is decrease in viral counts.
So will be positive later too.
Antibodies can be formed by 2-6 weeks. So these are not reliable in early phase. Once formed Antibodies too remain positive . They are considered conclusive tests after 3 months.
You can get back for any clarification.
Thank you
Dr Bharatesh D Basti
Above answer was peer-reviewed by : Dr. Prasad
doctor
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Follow up: Dr. Bharatesh Devendra Basti (46 minutes later)
Many thanks for u.. Appreciate ur patience.
doctor
Answered by Dr. Bharatesh Devendra Basti (19 minutes later)
Brief Answer:
Wish you safe and good health

Detailed Answer:
Hi
Thank you for wishes.

Wish you safe and good health.
You can get back for any clarification.
Thank you
Dr Bharatesh D Basti
Note: Consult a Sexual Diseases Specialist online for further follow up- Click here.

Above answer was peer-reviewed by : Dr. Prasad
doctor
Answered by
Dr.
Dr. Bharatesh Devendra Basti

Dermatologist

Practicing since :1998

Answered : 1764 Questions

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How Soon Is PCR Test Advisable After Intercourse?

Brief Answer: HIV RNA PCR sensitive after 10-14 days exposure Detailed Answer: Hi Thank you for query. I am Dr Bharatesh D Basti answering your query. Welcome back to health care magic. HIV 1&2 RNA PCR test is very sensitive (99%) after 10-14 days after exposure. It remains positive for life unless treated by anti-HIV drugs or immunosuppressive drugs or affected by immunosuppressive disease. The test is good after 10 - 14 days exposure. HIV 1&2 antibodies can appear 2-6 weeks after exposure latest by 3 months. They are considered conclusive after 3 months.They remain positive forever too. Hepatitis B PCR can be positive after 21-30 days exposure. But it's levels come down later as the bodies immune system takes over and antibodies appear. It is difficult to have conclusive results with this test if negative results. Later only the HbSAg(antigen) or the antibodies can be detectable.So HBSAg or antibodies to hepatitis B tests are also done to have conclusive results. You can get back for any clarification. Thank you Dr Bharatesh D Basti Dermatologist and venereolgist