Interpreting culture/blood test results

[kelly2456]

About a year ago, I developed symptoms of genital herpes about 4 days after a sexual encounter. I went to my doctor, who suspected it was in fact herpes, and she did a culture. The herpes culture came back positive for HSV-2. I was devastated! My first and only outbreak was the initial one, in December 2008/January 2009. My doctor prescribed Valtrex at that time, which I took, and the symptoms went away after about a week. The only issue I have now is a rather constant pain in both of my upper thighs-- it's not excrutiating, but it is a shooting pain that is uncomfortable at times. It started about a year ago, so I figured it was herpes related, but I've been told by two doctors that it is not a symptom of herpes. Anyway, a year after my positive culture, in December 2009, I had an IgG blood test for both HSV-1 and HSV-2. Here are my results:

HSV-2: .13
HSV-1: .80

My doctor told me these are negative results. I was completely confused and thought the results must be wrong, so my doctor recommended I wait a month, then repeat the blood test. I did. My results of the second test were:

HSV-2: .14
HSV-1: .72

My doctor told me again these are negative results. For the past year, I have done a lot of research on this subject, but I can't find anywhere a case in which a culture comes back positive, someone has no further outbreaks, then two negative blood tests more than a year later. I don't know whether to be happy or just utterly confused-- I'm a little of both right now!

Thank you so much. I really appreciate any help or advice you can offer!

[H. Hunter Handsfield, M.D.]

As I said above, the HSV WB is only done at the University of Washington lab in Seattle.  Any local lab will know how to refer a specimen them.  But don't expect too much from WB; it is the easiest of the options I suggested to sort this out, but the least likely to actually resolve the uncertainties.  When the standard IgG test is negative, usually WB is as well.  If positive for HSV-2, it will help settle the uncertainties.  If negative, or if positive for HSV-1, all the unknowns will continue.

Let's put this thread on hold until you have test results to report.  Good luck.  

[kelly2456]

I forgot to mention that the person I believe I got this from was not regularly taking the acyclovir--he was taking it only when he had an outbreak on his mouth, he said. I asked him if he was taking it when we had sex, and he said he no; the last time he took it was a few months prior. The reason that I was suspicous is because my initial outbreak was in a strange location, but it was also in a location where I am certain I had unprotected sexual contact with this person prior to having sex with a condom. I suppose I could inquire about his test results-- but I do not believe I would get an honest answer. (Jerk potential following our HSV conversation turned out to be quite high, in terms of saying one thing and doing another. I would bet he either never got tested for HSV-2, or that it came back positive. Although, I would be shocked if he did give me that information, whether it was positive or negative-- at the time, I think he was very much in denial about the possibility of having HSV-2).

I think I am going to do the Western Blot test-- but I did not see it as on option on the form for the lab I had been going to (Quest Diagnostics). Are there specialized labs that do this test? And, can I just go to those labs and request the test myself, or do you think I'd need a request from my doctor?

Thanks again very much for all of your help. This site was a great find!

[H. Hunter Handsfield, M.D.]

Thanks for the additional information. It increases my suspicion you might not have HSV-2. Cultures are rarely false positive, but testing for virus type is not as simple, especially for non-expert labs. Also, some labs don't actually determine virus type, and at the same time some health care providers assume that any genital HSV isolate is HSV-2 -- so perhaps HSV-2 wasn't actually confirmed. It could explain a lot if you really had HSV-1 rather than HSV-2. Genital HSV-1 often doesn't recur, and the HSV-1 blood tests are more often false negative than HSV-2. Definitely discuss these possibilities with your doctor.

Your symptoms were consistent with herpes, but transmission during condom-protected sex, by a person taking acyclovir, is a stretch. And don't you think your partner would have told you if his HSV-2 test had been positive? Maybe he didn't get tested. or was positive but didn't call; you're a better judge of his jerk potential than I can be. In any case, it would be good to find out if you care to contact him. If he definitely doesn't have HSV-2, it would support the notion you have HSV-1 instead; or that you don't have herpes at all.

Lots of testing "for all STDs" doesn't include HSV. Unless you know for sure your previous partner was really, this also might be explored further.

Keep me posted as you get more information.

[kelly2456]

Thank you again for the advice. I will look into those other options, although it is sounding like it's probably the result I was afraid of.

The initial test was a culture, not a PCR, according to the results form I have. My initial symptoms began about 4 days after my contact with the person I believe I got it from. I had extremely painful urination and what looked like a cut in my genital area. I am aware that I had unprotected contact with this person in the very same area where the "cut" appeared, before we had protected sex. When it first appeared, I assumed I just injured myself there somehow, or that it was from my underwear or something. It did not look like a blister to me but was so painful all the time, that it would keep me up at night. In a different location in my genital area, I had what looked a little like rug burn, which started at the same time. The doctor looked at that but did not know what it was.

I had a discussion with the person I believe to have gotten this from, and he said he has been positive for HSV-1 for many years and takes medication for cold sores on his mouth, but that he had no knowledge of an HSV-2 infection. I thought maybe it was possible that the acyclovir he takes for HSV-1 could suppress the HSV-2, if he were infected?  He agreed to get tested for HSV-2 and to let me know. (This was a year ago-- he never got back to me and I didn't ask-- I wanted to put it behind me, and we have minimal social contact now). Another reason why I believe to have been infected from this person is because my last partner was two years prior to this encounter and was a boyfriend who regularly got tested for all STDs, and all of his tests came back negative.

[H. Hunter Handsfield, M.D.]

Forgot to say above that you also should have another blood test by HSV Western blot, the ultimate gold standard for HSV antibody testing.  The lab will forward your specimen to the University of Washington lab in Seattle, where the test was developed.

[H. Hunter Handsfield, M.D.]

False positive cultures are uncommon, but I cannot say it never occurs.  The most likely scenario might be if your specimen and another patient's specimen were mixed up, but most labs take great pains to assure that never happens.  Alternatively, if the test was not really a culture but a PCR (polymerase chain reaction) test, there might be slightly higher possibilty of being falsely positive.  It is true that most people with new, symptomatic genital HSV-2 would have at least a couple of recurrent outbreaks in the next year.

Given the overall situation, I have to wonder whether the lab report was correct.  Here are some things you can do to help sort it out.  1) You might speak directly with the lab, or ask your doctor to do so.  Explain the situation and see if they have a potential explanation.  2) Can you describe the initial outbreak in more detail?  Whether it was typical or not might be a clue.  3) What do you know about the partner from whom you apparently were infected?  Was that person tested or otherwise known for sure to have HSV-2?  If not, that test might be done now to help sort this out.

4) Finally, you could self-collect several swabs from the labia and vagina, to be tested for HSV by PCR.  (Some labs offer HSV PCR; others do not.)  Several swabs can be tested together in a single pooled specimen.  If negative, it would argue against herpes (but would not disprove it with 100% certainty).  If positive, it would confirm you have HSV-2 and would also answer your closing question, i.e. whether or not you are shedding the virus without symptoms.

Don't misunderstand:  most likely the ititial test was accurate and you do have genital herpes, even if it currently is asymptomatic.  If so, it is likely you have asymptomatic shedding and can transmit the infection to future parnters.  But perhaps these leads will help you and your doctor work this out with greater certainty.  Consider printing out this thread and discussing it with your doctor or clinic.

[kelly2456]

Thank you for this information--- it is very helpful. I have not been on any anti-herpes medication at all, with the exception of after my initial outbreak. I was prescribed Valtrex in December 2008, and I took it for a little over a week, and it helped. From everything I have heard and read, I expected to have many outbreaks over the last year, but I have had none. I understand what you said about the blood test, but is it possible that the culture could have been a false positive? Also, do the lack of antibodies and outbreaks make me any less of a risk of passing this on? Thank you.

[H. Hunter Handsfield, M.D.]

Welcome to the STD forum.  I'll try to help.

The blood tests for HSV are inherently less reliable than tests to identify the virus in genital lesions.  With a positive culture for HSV-2, you can be sure you have it.  About 10% of people do not develop measurable antibodies by blood test -- so although your blood test results are atypical, they are not all that unusual.

You don't say whether you have continued to take valacyclovir (Valtrex).  If so, it might have interefered with developing a positive blood test.  That's not supposed to happen, but sometimes it may occur.  Of course taking the drug could also have prevented any further outbreaks that otherwise might have happened.  If you have in fact been taking anti-herpes therapy all this time, it probably would be best for you to stop it and see what happens.

As for your leg pains, herpes probably is not responsible.  Herpes can cause nerve-related pain (neuralgia), but typically only briefly in the days before a recurrent outbreak of genital lesions.  Conceivably chronic pain can be caused by HSV-2, but not likely.  Here is another thread that discusses this:  http://www.medhelp.org/posts/show/491205

Please let me know whether you have been taking anti HSV therapy all this time and we'll take it from there.

Regards--   HHH, MD