[Question #1275] HIV 2 Test Window and Combined Test Accuracy

83 months ago
Good afternoon. I'm curious to know more about HIV 2 test windows. As background, I had intercourse with a friend of African origin about six months ago. I don't know his HIV status and don't feel comfortable asking unless necessary. A month after this I had a weeklong episode of high fever, body chills, night sweats, leg cramps and fatigue. I was so tired I could barely walk to the clinic. I also had 2 days of severe diarrhea and nausea - I was in the bathroom every few minutes. I didn't think much of it at the time, but when I started developing a rash all over my upper back and arms after the fever subsided I thought it would be better to get tested. I got tested twice - once at 6 weeks and another at 12 weeks. The first was the 4th generation combo, I'm not sure what the second one was as my doctor didn't specify but I think it was a combined test. I didn't mention anything about my partner's origin as I didn't think it would be relevant. Both came back negative and I had put it behind me. 

I recently read about a man with HIV 2 who went undiagnosed in the USA despite repeated testing and didn't test positive till a year after, although he had experienced seroconversion symptoms a few weeks after intercourse. Given my partner's foreign background, I am worried that this might also be happening to me. How conclusive are the combined tests at 12 weeks? Are tests built to be more sensitive to HIV 1, given it's greater prevalence in the USA? My main concern is the weeklong medical episode I had, at approximately 4 weeks after intercourse, which I cannot dismiss as just anxiety. Can I take my 12 week combined test results as conclusive?  Should I take another test now? (6 months post-encounter.) Any other information on HIV 2 testing would be welcomed, as I can't find much on the internet. 

83 months ago
As an update - there was a mistake with my tests, my annual comprehensive std package testing did not include an HIV test as I thought, which is surprising, I only just found out when I called to ask what type of HIV test it was. This ups the anxiety stakes for me. How conclusive is an Alere 4th Generation for HIV 2 at 6 weeks?
H. Hunter Handsfield, MD
83 months ago
Welcome back yet again. But based on all these questions, I think you are far more concerned about STDs in general than is necessary or warranted by their frequency or your risks.

HIV2 is virtually absent in the US and Western Europe. Almost all of the rare cases reported are in people who were born and infected where HIV2 evolved and remains endemic, a small are a of West Africa (Cameroon and nearby). There have been very rare cases in those persons' sex partners, but not in anyone else. That's why you can't find much information on the internet -- it's too rare to warrant attention. The important "take home" message of only a single report of a man who had undiagnosed HIV2 is NOT that HIV2 is a risk for others, but that it is so rare that even a single case gets media and/or online attention. Any time there is only one report of someone with a particular medical problem, it's a good bet that nobody else needs to worry about it. In any case, his delayed diagnosis must have occurred a few years ago. The standard HIV tests now in routine use world wide detect HIV2 as well as HIV1. Your 4th gen test at 6 weeks is 100% conclusive for both HIV1 and 2.

Regards--  HHH, MD