[Question #12633] False Positive/Negative Throat Gonorrhea

6 months ago

Hello. I’m looking for some help understanding mixed results I’ve recently received from throat swabs for gonorrhea. I have a history of giving and receiving unprotected oral sex with both males and females. My most recent encounter was in September. I have not experienced any throat std symptoms.

14 days after last encounter I got a 3-site chlamydia/gonorrhea self collection test from TBD Health. Results were negative.

5 weeks after last encounter I did a 3 site test from MyLab Box. All negative.

4.5 months after last encounter I did a 3 site test from MyLabBox and came back positive for oral gonorrhea.

I have not had any sexual contact since the September encounter and have not been on antibiotics at any point. I follow the collection instructions as best as I can and may have brushed one of my cheeks on the way out/in with the swab on my most recent test.

Given this, how should I interpret the negative, then negative, then positive test results? What is the likelihood the first two were false negative or the most recent was a false positive? I believe MyLab Box uses a NAAT PCR test for gonorrhea if that matters.

H. Hunter Handsfield, MD

6 months ago

Welcome to the forum. Thank you for your confidence in our services.

The problem here is very clear, and it is non-medical. It is your compulsive repeated testing! No lab tests are without potential error. Your positive pharyngeal (throat) test for gonorrhea was falsely positive: you don't hae it. Why did you keep repeating the tests anyway? Especially after 4.5 months???

You may not realize that oral (pharyngeal) gonorrhea is mostly harmless. It rarely causes symptoms, is hard to transmit, and goes away within a few weeks.

The pharynx is normally inhabited by several bacteria closely related to Neisseria gonorrhoeae, the cause of gonorrhea. This creates challenges in developing tests for N. gonorrhoeae itself. It is likely that from time to time, the test detects these entirely normal organisms. It is therefore a mistake to overtest: the more you do it, the greater the chance of such a false positive reslt? There is no realistic chance that the first two results were false and the last one true. Another aspect is that pharyngeal gonorrhea almost never lasts more than a few weeks. It is nearly impossible to still be infected 4+ months after exposure.

You do not have pharyngeal gonorrhea. All is well.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

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6 months ago

Thank you, Dr. H, for your reply! That all makes sense. The reason for the additional testing stemmed primarily from me being worried about a possible anal infection and using the 3 site test to check for anal infection.

During the September encounter, I also had receptive anal sex where the condom failed and the top ejaculated in me. Since that encounter, I’ve had intermittent pain and itching around my anus and what appear to be multiple linear anal fissures occurring laterally (sides of my anus). When the fissures first appear, they result in a decent bit of blood when wiping with TP which tapers off over about a week.

I’ve tested a few times (including at 4 months post exposure) for HIV, syphilis, HSV 1 and 2, Hep A/B/C, via blood tests and the aforementioned three 3-site chlamydia/gonorrhea tests. All tests were negative except for the previously discussed throat gonorrhea test and HSV1 which I’d previously known I was positive.

I’ve read that lateral fissures are atypical and often are secondary to something else, including stds. Based on my tests and symptoms, could these fissures be related to an std - whether from false negative tests or an std I haven’t tested for (chancroid, Mgen, trich, etc?

Thank you!

H. Hunter Handsfield, MD

6 months ago

Was the positive HSV1 result a PCR or blood test? If PCR, was it oral or rectal? If rectal, herpes is a likely cause of the anal fissures. Trauma from anal penetration might be playing a role as well, especially since it seems you began experiencing pain soon after the event. I have no comment on whether "lateral" perianal tissues are less likely due to STI like gonorrhea, chlamydia, or herpes -- but a proctologist or other provider with in-depth experience with anal health, and with both STIs and traumatic events, likely knows more about this than I do. Most important, negative anal test results at this time are strong evidence that those infections are not now contributing to the problem. It's possible for such infection to start an infmalltory process than then continues after the infection itself is gone.

Mycoplasma genitalium and Trichomonas vaginalis are not likely contributors to anal disease; almost all infections are limited to women and their male partners. However, research on these as[ects is underway and maybe they'll turn out to be important issues in MSM. Chancroid is currently absent in the US and effective testing is unavailable.

It is unclear to me whether you are in proper care by a provider who understands anorectal STD and other aspects of anal health, such as a proctologist or colon and rectal surgeon. This definitely not an area that can be properly managed by self assessment and self-determined lab testing.

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