[Question #7879] HSV Testing

51 months ago

I have a question about false negatives in relation to IgG testing. I have seen you say that the HSV-1 test misses 30% of cases and the HSV-2 test misses 8%. Are you saying that the false negative rate for these test is 30 and 8 percent respectively? In might time reading about the test it seems like they are very sensitive. I really am mainly concerned about false negatives with these tests as opposed to false positives. I am implying that these tests are being done 12 weeks after exposure. Also why do false negatives happen? And do false negatives happen in people who have “symptoms”? Especially for HSV-2. I am curious how antibodies mounted against an infection could not be detected accurately. Is it related to the individual or to the test? Like hypothetically if I had HSV-2 and I got a false negative after 12 weeks, would I always receive a false negative if I received another IgG test. I use anylabtestnow if that helps at all (but would use another lab if there is a better one).

Also is there a length of time after you recommend not getting PCR on a lesion (ex: if the lesion has been around for 20 days doing PCR would not yield an accurate result)

Also this paper you co-authored (Reactivation of Genital Herpes Simplex Virus Type 2 Infection in Asymptomatic Seropositive Persons) is incredibly insightful. During this 3 month study do you have any idea what percentage of the 38% percent of individuals who did not report herpetic lesion also had HSV-1. I found the diaries very insightful.
Thank you so much for all you do. Its incredible the amount of questions you answer.

Terri Warren, RN, Nurse Practitioner

51 months ago

Yes, in a population of people who are being screened for sexually transmitted diseases and herpes testing is included, compared to the western blot in these people who had both tests, the IgG test missed 30% of infection with HSV 1 and 8% with HSV 2.

False negatives are clearly a function of the IgG test because the blot picked up antibody.

Repeating the test, has not, in my experience, picked up anymore positives in the same person using the IgG test.

I would say even the PCR might miss herpes in a 20 day old lesion.

I don't recall the breakdown in what the HSV 1 status of our subjects was.

Terri

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51 months ago

Hopefully this will be the last time I post here. I am a 25 yr old male medical student with no health conditions. Never had something I would consider a cold sore (I am especially familiar with what oral herpes looks like). Have always tested negative for HSV 1 &2 on IgG tests. Never taken any antiviral. With my second to last partner (who was a PA) I tested negative for HSV 1 &2 8 and twelve weeks after our last protected encounter. I had protected vaginal sex and unproteced oral sex, 1 time, 3 weeks ago with a new partner with no history of genital lesions or ulcers. She even saw a derm and OBGYN around 7 days after we had sex who saw no signs of a herpetic outbreak. Recently, I have had these red bumps that in my opinion do not appear as classic herpes but I'm aware that the virus can present atypically. My derm said it was unlikely but possible they could be scarring from hsv. Anyways, my question is if my new partner tests negative for HSV 2 can I essentially rule the possibility of these bumps being caused by HSV-2? She has not had any type of sex in 2 years. GHSV1 does not cause me great concern. Or would you recommend any more IgG testing? I really want to rule out HSV2 short of doing WB. I know I could test again 12 weeks after my last encounter but at what point am I just being ridiculous and too anxious.

Also why do you believe the uspstf rates the sensitivity for HSV-2 Herpeselect much higher than you do? They have the sensitivity at 99% with the 1.1 cutoff (https://jamanetwork.com/journals/jama/fullarticle/2593576)

You are so amazing. Thank you.

51 months ago

My new partner's IgG values from Quest diagnostics were <.90 for both HSV 1 & 2.

51 months ago

My 8 week negative results were via labcorp. My 12 week negative results were via Quest. I am realizing this matters since it seems the Captia test is less sensitive than Herpeselect for HSV-2

Terri Warren, RN, Nurse Practitioner

51 months ago

There is no evidence that Captia is less sensitive than herpeselect. In my opinion, all the IgG brands perform about the same.

The statistics that you read on the packaging of the IgG test compares the ability of the IgG test to pick up antibodies in people who are KNOWN to have HSV 2 by culture or another swab test. But the population like you, are completely different. This is a screening population, not a population with known infected people doing an antibody test. As it turns out the statistics are very very different (which one might actually expect.).

If your new partner is negative for HSV 2 and you are negative now, then I think you can take this off your worry plate

Terri

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