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Dr. Anil
Dr. Anil, Doctor (MD)
Category: Health
Satisfied Customers: 8007
Experience:  M.B.B.S.M.D with over 30 years of experience in this medical field.
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False Negative HIV test after 18 months?

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Hello. I was wondering if it's possible to have a false-negative HIV test a year and a half after exposure. About a year and a half ago I had unprotected sex with a girl I didn't know and two weeks later I was covered in hives and had the worst sore throat and headache of my life.  This lasted for about three days then went away completely. I told my doctor this and took about every STI test available and they all came back negative. I didn't actually get the results from my doctor so I didn't have a chance to ask him if the single HIV test is 100% accurate, or if I should have another one done. Do you think that is necessary? Thank You.


After six months of the exposure the HIV antibody test can detect the infection in 99.8% of the cases.
Only people who are severly immunocompromised can have a false negative result.(0.2%).

So in a normal healthy male of your age chances of false negative are negligible after 6 months of exposure.

I hope this helps.
Dr. Anil and 4 other Health Specialists are ready to help you
Customer: replied 3 years ago.

Thanks for the quick reply! So is there something else I could have contracted from the exposure that causes the symptoms above? Or do you think it's safe to say it was just a coincidence that I had those symptoms at that time?

Probably the symptoms you describe may be due to allergic manifestation and not due to any STD.
Probably a blood work called AEC levels and IgE may be done to rule out allergy.