[Question #3846] Does Hiv and Hcv co-infection effect the window period of the 4th gen hiv test

32 months ago
Good evening Dr.'s 

I have a follow up question.  While doing my research on the cdc website I ran into the following informaiton;  

"Strong preference should be given to an Ag/Ab combination test over antibody-only options, and oral fluid should not be used. Follow-up testing should occur 4 to 6 weeks and 3 months after baseline, with additional testing at 6 months if the exposure event resulted in hepatitis C virus infection.27 These recommended time points reflect expert opinion rather than a strict adherence to window period durations. If the patient tests negative at the end of the window period (Table 1), one can be very confident that he or she did not acquire HIV from the exposure."

Is it possible for the testing window to be longer with the 4th generation hiv test if there is a  possibility of either having hep c, or contracting it during the same exposure?

The paragraph says that "these time points reflect expert opinion rather than a strict adherence to the window period durations"  Can you clarify what the cdc means by this?

Thank you.




H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
32 months ago
Welcome back, but I'm sorry you found it necessary.

First, hepatitis C is not a risk or concern for the exposure described in your previous thread. Hep C has been oversold as an STD; it really shouldn't be considered an STD at all. The only proved or common sexual transmission scenario is between men having potentially traumatic (bloody) rectal sexual practices, e.g. fisting. Analingus is not a risk at all.

As for window periods, the CDC statement makes it clear that it's being extra cautious based on a few physicians' individual experiences ("These recommended time points reflect expert opinion"). There are no actual studies that document a delayed HIV window period in people who have (or simultaneously acquire) hepatitis C virus. They're just saying, indirectly, what I just did:  there are no solid data in favor of such testing practices. I can also tell you that busy STD/HIV clinics pay no attention to HCV in advising patients about testing intervals for HIV.

So nothing at all to worry about. This doesn't change my advice in your previous thread.

May I suggest you stop searching the internet about all this? Like many anxious persons, it seems you're being drawn to information that reinforces your anxieties and missing the reassuring information that also is there.

Best wishes--  HHH, MD
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32 months ago
Dr. Handsfield,

I agree, I am sorry I found it necessary as well.  Thanks for your reply,  your information is comforting.   Unfortunately I have gotten into the habit of exploring the internet, only to find conflicting information, or taking information out of context and thinking the worst.

Would you mind please answering and reinforcing the following questions?

1. After my 46 day post exposure negative 4th generation ag/ab hiv 01/02  test do you feel confident that I officially hiv negative?

2. If for psychological reassurance purposes only i decided to get one more test at 12 weeks for this single exposure would you feel confident that the test result would be negative?

3. Are you confident that there is no reason for concern that HCV  exposure or possible HCV contraction would in any way alter my negative HIV test at 46 days post exposure?

These will be my final questions.  If i continue to struggle with anxiousness I will absolutely seek counseling to get past my fears.

Thanks once again for your service and help.
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
32 months ago
1) Yes, 100% confident.

2) Yes. If positive, you would have to look for other possible exposures besides the one you described in your other thread.

3) Yes I'm also confident about this.

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32 months ago
Dr. Handsfield,

Your responses and explanations have been a big help to me.  

Once again, since I have one question left, I would like your opinion on one more thing.  

 The information on the cdc website regarding 6 month testing for people who have contracted hiv and hcv in the same exposure had a citation that i missed.  After reading the citation it indicated that the 6 month testing is indeed recommended.  However it does say specifically that this hiv test recommended be an antibody test, which to me may make sense because at this point it is possible that p24 antigen may not even be detectable at the 6 month period since antibodies have taken over. 

Is it reasonable to think that this is the reason for testing out as far as 6 months with an antibody test only if a co-infection could exist?  

I guess my main question is, regardless of possible hiv delayed seroconversion due to a possible hiv and hcv co-infection, a 4th generation test should be able to still detect p 24 antigen in the early stages of infection regardless of the hcv infection, is this correct?

Thanks again, and take care.


H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
32 months ago
I'm not familiar with this publication or the details of the CDC statements. But it sounds to me like this originated before p24 antigen testing, or the Ag/AB test, were generally available. I very much doubt testing is required beyond 6 months even in the presence of HCV infection. In any case, I certainly see no need for such delayed HIV testing in the absence of HCV infection.

I hope the discussion has been helpful. Best wishes and stay safe.
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