HomeAnswersHIV/AIDS specialisthivMy HIV 4th generation duo antigen/antibody test came negative after 31 days. Can I still be infected?

How accurate is HIV 4th generation duo antigen/antibody test?


The following is an actual conversation between an iCliniq user and a doctor that has been reviewed and published as a Premium Q&A.

Medically reviewed by

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Published At February 22, 2022
Reviewed AtDecember 1, 2023

Patient's Query

Hello doctor,

I had unprotected sex with a CSW(Community Sex Worker) last month. Two days later, I got her tested at a reputed pathology laboratory for HIV(Human Immunodeficiency Virus) 4th generation duo antigen/antibody test, HBsAg, and HCV(Hepatitis C virus). All tests were negative. I never had any of the HIV symptoms. As it could have been a high-risk exposure, I got tested on the below dates, and all came back negative: HIV 4th generation duo antigen/antibody Test - non-reactive (0.172) at 20th day after exposure. HIV 4th generation duo antigen/antibody Test - non-reactive (0.172) at 31st day after exposure. I have shared my reports as an attachment. How accurate are these results? Do I need any further testing? Please guide.



Welcome to icliniq.com.

I have checked your reports (attachment removed to protect the patient's identity). It is good that HIV 4th generation duo antigen/antibody test is negative after 31 days of exposure. The chances of HIV (human immunodeficiency viruses) tests coming positive later are almost nil. However, it would be better to go for an HIV antibodies test after three months of exposure to get relieved of anxiety.

Patient's Query

Hello doctor,

Thank you for your suggestion.

I would like to know about the window period of the HIV 4th generation duo antigen/antibody test. Will a negative result at 45 days be considered conclusive?


Welcome back to icliniq.com.

HIV 4th generation duo antigen/antibody test is considered almost conclusive after one month of exposure. But it is better to go for an HIV antibodies test after three months of exposure to be relieved of anxiety and definitive results.

Same symptoms don't mean you have the same problem. Consult a doctor now!

Dr. Basti Bharatesh Devendra
Dr. Basti Bharatesh Devendra


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