Western Blot Test Accuracy:

Hello, I have a question about the Western Blot test and it's accuracy.  I've read that the Western Blot Test is 98-99% accurate, with possible "negative" results occuring when someone has been exposed to HSV within the last 14-16 weeks or the levels of antibodies are too low to be detected.

I'm in the unfortunate situation of having been infected with HSVII, due to my partner's negative Western Blot test result.  When tested, he had been in a monogamous relationship for over 6 months.  He originally went to his general practice doctor for STD testing, and received a postive HSVI and HSVII result.    His girlfriend at the time, had all negative results. Based on his positive result, he was tested again at an STD clinic, and had a positive result again (For both HSVI and HSVII.) He decided to go to a specialist that performs the Western Blot Test.  He explained the two past prior positive results, and when the results came back - was told that he had HSVI antibodies, but NO HSVII antibodies. I've also seen the letter this lab sent, corroborating this.
  To make a long story short, after their relationship had ended (6 months later), a few months after that - he and I began an exclusive relationship, we did not use protection -since both of us had been tested in the past, both with negative HSVII results (In my last test, I was negative for both HSVI and HSVII).)  Within 3 weeks, I had symptoms, and was diagnosed both visually as well as by a culture test.  Devastated, we both returned to the specialist where my partner had originally gone for testing.  They compared his old blood work with his new blood work - found that he was positive now - and that yes, in fact, the blood drawn over a year ago - did show early stages of the infection - so he fell into that 1% error category.  My test came back as showing early signs/inconclusive, which obviously meant that I had contracted this from my current partner.  

My question here really is - if the less effective tests were picking up antibodies in his blood over a year ago - but the Western Blot came back as negative - was this truly the test error or USER error in making a diagnosis of the results? In addition, since he had been in this monogamous relationship for 6 months, he would have contracted the virus prior to that, and should have had enough antibodies in his system for detection (as was obviously concluded by the first 2 tests he'd taken).

Any clarification on this would be much appreciated! Thanks!

[H. Hunter Handsfield, M.D.]

No HSV antibody test is perfect.  (Indeed no diagnostic test is perfect, although modern HIV antibody tests come close, happily.)  The Western blot is not 100% sensitive, meaning it misses a few infected people; that is, the non-WB diagnostic tests (e.g., HerpeSelect) actually is a little more sensitive.  The main purpose of a WB is to confirm another test that is positive--NOT to diagnose absence of HIV in someone with a positive standard test.  Also, WB tends to become positve more slowly than the type-specific ELISA tests.

Given the positive results of 2 type-specific serological tests, the WB really was not indicated and probably should not have been done.  I would not have ordered the WB; and if I had, when the results returned, I would have informed the patient that s/he probably had herpes, or was in the process of seroconverting--which, in retrospect, probably was exactly what was happening.

As to who was infected when, I can't answer that an won't try.  But at this point, perhaps it doesn't matter.  You and your partner both have HSV-2.  As long as you are together, and there are no other partners, it should be no big deal.  You cannot reinfect each other, and if you have bothersome symptoms, you can be treated. Your infection might be a concern if your current relationship ends and you're out there dating again sometime in the future; but I suggest worrying about that possibility then, not now.

Good luck--  HHH, MD

[emt]

Unfortunately, the tests were done at different labs - so no one doctor was looking at all of the results.  My concern here is that the lab that performed the WB gave the impression that since his tests results were negative he therefore did NOT have HSVII, and they were informed prior to the test being done, that he had 2 positive results in the past.  I was not present for the conversation, so I can't tell you what the person who told him the results over the phone did say.

Based on the test coming back as "in the beginning stages" - would you say that the results did actually come back positive initially, yet were diagnosed as negative?

[H. Hunter Handsfield, M.D.]

I have no way of knowing exactly what the original test results were or what any particular lab or provider advised you or your partner about the results.  And absolutely I will not get dragged in to helping you decide whether your providers were practicing proper and prudent medicine (which I have a sense you might be seeking).

HHH, MD

[emt]

I can see how you might think that, however, I do realize that this lab does FAR more good than "bad".  I guess my main concern really is that there seems to be some overconfidence in the test's accuracy and that currently there is not the best process in place for making sure that people don't hear just want they hear - that they may be negative showing negative results today but maybe not a month from now...

Thanks for your information and guidance.  Much appreciated.

[monkeyflower]

"currently there is not the best process in place for making sure that people don't hear just want they hear"

I can't imagine any process that could even begin to prevent people from only hearing what they want to hear, and I can't imagine what could have been done differently. Rather than wasting your energy arguing or worrying about the testing accuracy, I'd suggest you work toward acceptance.