HepC (and B) Test Window

[PBotha]

Hi doctors.

I know HepC isn't 'normally' considered an STD, but opinion seems divided. Plus I'm going out of my mind from worry after a sexual encounter.

I was wondering if anyone out there could give me some advice about the testing window period for HepC.

Here's my situation. I had a potential exposure to HepC 18 weeks ago. I tested negative for HCV antibodies this week. I've looked elsewhere online, and some people say that the window period for testing is 3 months (12 weeks), while some say that it is 6 months (24 weeks). I'm from the UK, and the NHS guidelines here state 12 weeks.

I was wondering how reliable you would consider the antibody test at 18 weeks? I've read that there's also a PCR test that can tell you if you have a current infection, but some doctors say that this shouldn't be used for diagnosis, but just for confirming a positive antibody test or monitoring viral load. Do you know why this is? I've heard that there's a greater chance of a false positive with PCR. Is this true?

It's now 18 weeks since my exposure, and I'm thinking about cutting to the chase and taking a PCR test, but I'm scared about getting a false positive from the PCR test, and what it would do to my mental-state if that happened. Would the antibody test be a strong enough indicator of infection at this stage?

I was worried about HepB, but have also tested negative for HBsAG this week as well. Am I right in thinking that the test for this is conclusive?

Thanks in advance. This is a great forum, so keep up the good work!

Pete.

[H. Hunter Handsfield, M.D.]

Thanks for the thanks about the forum.  But if you  "know" HCV isn't "normally" sexually transmitted (or abnormally sexually transmitted, for that matter), why are you asking the question?

If your exposure 18 weeks ago was to someone's blood, e.g. sharing injection equipment, you might be at risk. If it was sexual, even with a partner known to have HCV, there was no risk worth worrying about.  HBV is often sexually acquired, but the risk is very low for any single encounter.  (Most STD/GUM clinics generally don't even offer routine HBV testing.)

To my knowledge, HCV tests always become postive well before 18 weeks.  So you're home free.  But because it's not an STD, I don't keep up on the details of testing techology.  False positive PCR results undoubtedly are uncommon, but I do not know the actual frequency. The negative HbsAg test shows either that you weren't infected or, if you were, that you have not become a carrier, i.e. you are not now infected with HBV.  For further information on all this, you need to ask the provider to did your testing.  (If you just tested yourself, e.g. through an online testing service, go see a health care provider and follow his or her advice about testing, interpreting your results, etc).

HHH, MD

[PBotha]

Hi Doctor,

thanks for your reply. I'm in the UK, and the advice we get here is that HVC is transmittable through sex, but not very often. As I said opinion seems divided.

A quick question - has anyone using the forum ever caught HepC from sex? My exposure (which I know is very low risk, but it's amazing the difference it can make when it's your own health and the impact on your family) was protected vaginal and unprotected oral. Has anyone heard of someone catching HepC that way?

Cheers,

Pete.

[H. Hunter Handsfield, M.D.]

The truth about hepatitis C and sexual transmission is that the spouses of infected persons have a somewhat higher rate of infection than the general population.  But even that applies only in people married several years.  Also, the rate is somewhat higher in gay men who are partners of HCV infected men, but again only modestly.  Among heterosexuals who are only occasional partners of HCV infected people, study after study finds no increased risk of infection.  Even among spouses, there are no data whatsoever that sex per se is the mechanism of transmission.  Among men who have sex with men, the likely route has to do with the inherently traumatic nature of anal sex, i.e. blood exposure.

To my knowledge, there has never been a documented case of someone having a single episode of sex with an HCV infected person and then being shown to have acquired HCV during that event.  Of course it probably happens, perhaps especially if the sex is somewhat traumatic and there is overt bleeding, but too rarely to measure.  For these reasons, no STD expert recommends HCV testing as a routine STD screening strategy.  That internet testing outfits include it results from hype, promoting the fear factor, and because it makes them a lot of money.

And no, nobody on this forum has ever reported that they tested positive for HCV after a sexual exposure.

[PBotha]

Hi Doctor,

thanks again for your reply. I apologise about my lack of knowledge about HepC. It seems that most questions on the forum, and on the Internet in general, are about HIV, so HepC information isn't as easily available.

As I said, my exposure was protected vaginal sex and unprotected oral, which I understand equates to a very low, or even zero risk for HepC. I was especially concerned because there was quite a lot of fingering involved (me to her), and I read that menstrual blood can carry HepC. I know that this isn't a realistic risk for HIV, but is it the same for HepC? And if it's isn't a risk, how come?

Cheers,

Pete.

[H. Hunter Handsfield, M.D.]

You're basically asking why HCV isn't transmitted sexually.  Most likely because HCV isn't present in genital secretions.  I don't know for sure - but this doesn't matter anyway.  Since you're not at risk, the reasons aren't important.

This thread is over.