[Question #303] high risk HIV

106 months ago

Dear Doctors,

I used this service earlier and it was really helpful.

This time is not about me. A very dear friend (lady) is going through a very difficult time: while having protected vaginal intercourse with a partner met recently the condom broke; she is not sure how long it took to discover the condom failure. He confessed afterwards that he is HIV+ since about 2 years. He was genuinely concerned but this does not help the situation. My friend was in absolute shock and interrupted the contacts with him. She does not know the viral load nor if he is undertaking treatment. She took a 4th generation test at an STI clinic part of a large public hospital. The test was exactly at the 28th day with negative result. The clinic recommended another test at 3 months and she tested negative (Combo again) at exactly 84 days (or just 12 hours short of it as she says).

Here are the main questions:

1) I mentioned that many experts (including yourself) consider Combo tests conclusive already at 4 weeks; reading this straight from you might help understanding that she is over it. Can you please comment?

2) She is confused about "the 3 months definition": somewhere (WHO webpage and UK National Healthcare) it says 12 weeks. Somewhere else it says 90 days. She is very distressed and hopefully the last days at 83,5 days is final. Is there any meaningful difference between 84 days and 90 days? Need another test?

I will print the answer and show it to her hoping that it will help (in my case it relaxed the anxiety although it was a much lower risk case).

Thanks,

Edward W. Hook M.D.

106 months ago

Welcome to the Forum. From what you report, your friend did not get HIV from her exposure. To provide you with some context for this, your friend needs to remember that her risk of infection, if her partner was not on therapy for his HIV is, on average, one infection in 1000 exposures. Thus her risk for infection was 1/10th of 1%.

In answer to the specific questions you asked:

This statement is correct, Unless she was taking post exposure prophylaxis 4th generation HIV tests detect nearly all (over 99%) of recent infections within 4 weeks/28 days following exposure. This has been shown in numerous carefully conducted scientific studies.

The "3 months" period is defined differently in different studies and situations. In some studies this is 12 week (84 days) and in others "three months is defined as 90 days. In either instance, the studies have shown that all tests taken at this time provide definitive results.

The bottom line here is that your friends tests, both the ones at 28 and 84 days prove that she was not infected with HIV by her exposure. There is no need for further testing. Your friend was not infected. EWH

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106 months ago

Thank you very much for the prompt and clear reply! I believe she will be relieved once I will share it; she received same info from the nurse at the hospital but after such stress she needed further reassurance.

Couple of follow up for further reassurance.

1) the 12 hours short of 84 days is it a concern? just to explain: the exposure happened on a Wednesday night while the test was taken 12 weeks afterwards during Wednesday morning, so roughly 12 hours short of the "official 84 days".

2) Is a combo test at 4 and 12 weeks able to detect both HIV1 and HIV2 and all subtypes?

Thanks again

Edward W. Hook M.D.

106 months ago

this will be my final response. If your friend has questions, she should ask them herself (or not pretend to be asking for someone else)

Repeating the question does not change the answer. the test result at 83 days and 123 hours is reliable. Combo tests are reliable after 4 weeks.

2) Is a combo test at 4 and 12 weeks able to detect both HIV1 and HIV2 and all subtypes?

Yes

EWH

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