False Positive Suspicion

[MMTex]

I’m a male, 27. I’ve had two long-term sexual/romantic partners and one casual, sexual encounter. The casual encounter, which occurred recently, is the event which led me to get tested since I have no knowledge of their history.

The encounter was short-lived, lasting about a minute or two. I used a condom and there was light, infrequent kissing (closed mouth/no tongue).

About two-three days after said encounter, I began experiencing headaches and a fever along with back pain. I’m unsure if these are symptoms of herpes or another illness as it is flu season, but these symptoms persisted for about a week which is unusual in my experience when it comes to the flu, especially without congestion or coughing. I got an STD panel done 7 days after the potential exposure. Negative for HSV1 and Positive for HSV2 at 1.41 on an IgG test.

To date (11 days after exposure), I’ve experienced headaches, fever, and back pain. The first two have dissipated and the back pain is still lingering. I’ve had no tingling/burning/numbness or other sensations, or sores/blisters, on or around my mouth/genitals.

I’m thinking it’s a possible false positive since I’ve had no sores/blisters and I’ve been told 7 days from the event is too soon to turn up a positive test. Should I test further? If so, how long should I wait?

[MMTex]

I forgot to mention that I got tested two days after the event and was negative.

Timeline:

Monday – Sexual Encounter
Wednesday – Blood taken for testing
Saturday – Results received, negative
Monday – Blood taken for second test
Friday (Today) – Results received, HSV2 Positive

[Terri Warren]

I think it is too early for a test to indicate true infection, from your encounter. In addition, a condom-protected encounter lasting a minute or two is an incredibly low risk situation for contracting herpes in the first place.

Either you had HSV 2 prior to this encounter OR it is a false positive. Given your index value, there is about an 85% chance that this is a false positive.

My suggestion is to repeat the IgG test in 6 weeks and see what it shows. If it continues to be a low positive, we can do the western blot at 12 weeks out. I’m sorry you’ll have to wait to find this out. Honestly, I don’t think this low positive indicates a new HSV 2 infection from this encounter.

Terri

[MMTex]

Update: I went into a clinic due to something that looked like a sore on the underside of my scrotum. Turns out, it was a friction burn but while I was there, the doctor talked me into taking another IgG test since I told him I had tested positive for HSV2. This test was about 3 weeks out from the possible exposure.

The test came back positive at 1.66. The lab that did the test conducted a reflex/supplemental test, something that the other lab did not do. This reflex test came back negative. At this point, I don’t know what to think.

I’ve also started experiencing symptoms that the internet most closely relates to something called epididymitis. I can’t seem to find any information that attributes these symptoms to herpes. I’ve experienced:
-Strange/Uncomfortable sensations in the pelvic area (not pain, more like feelings of being poked)
-Warm, reddish, shiny scrotum
-feelings of testicle tenderness (although NOT tender when handled)
-pelvic muscles feel strained during urination
-most recently, a slight burning sensation at the tip of the penis following urination

To Recap:
11/14 – Sexual Encounter
11/16 – MedPost STD Panel – 11/19->Negative
11/21 – AnyLabTestNow STD Panel – 11/25->HSV2 Positive 1.41
12/3 (19 days out) – MedPost Herpes test only – 12/7->HSV2 Positive 1.66/Reflex test negative

I haven’t had an outbreak to date. I have a couple of questions regarding this information.

Could herpes be responsible for these symptoms?

My last STD panel was a week after the sexual encounter (I haven’t had sex since) and came back negative for chlamydia, gonorrhea, HIV, and HSV1, but positive for HSV2. Is it possible one of these tests was a false negative and could be causing these symptoms? I didn’t test for syphilis. I used a condom during the encounter and everything I’ve read suggests chlamydia and gonorrhea transmission is nearly zero with one present.

If I DON’T have herpes, then why am I getting positives? What causes false positives?

[MMTex]

I’ve been trying to better understand my latest test, specifically the reflex portion. This is probably not news to you, but I found that the reflex test is not the same as the original test.

This is from the lab’s website: Chemiluminescent immunoassay (CLIA). Reflex of specimens equivocal and low positive for HSV-2 type specific IgG to a membrane based immunoassay.

So, I’m not sure if that improves the odds of a false-positive because I have no clue as to the efficacy of a “membrane based immunoassay” over the first-performed CLIA. Whatever the case, I thought I would include this information.

[Terri Warren]

False positives are caused by the inability of the test to distinguish herpes antibody proteins in your body from other proteins.

I would say if you were farther out from the sexual contact, that it is very likely that you have a false positive here, but you are still too close to the contact for accuracy. The supplemental could be accurate or it could have been done too soon after the contact to be accurate.

I would recommend that you consider getting another igG test at 6 weeks out and see what you get. If you are still hovering around that low positive range with another supplemental negative, then wait 6 more weeks and do the blot for certainty

Terri

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