[Question #1912] Trichomonas

89 months ago

Hi Drs. First, I want to say thank you for your participation on this board as I know it is a great help to many people, especially on the internet where it is so easy to obtain incomplete or wrong information about these topics. About 2.5 months ago, I had an unprotected oral and vaginal sex encounter with a women I don't know well. Of course, I became concerned about this and 3 days after the encounter I was tested for: HIV-1 PCR, syphilis, Hep. b and c, and urine tests for gonorrhea, chlamydia, and trich. All negative. I realize that it was too soon to test for most of these. Last week, I tested again for the same set and received a positive test for trich. I took 2g Flagyl single dose a few days ago. I told this partner about it, she was tested with the same panel of tests which resulted today as all negative.I believe I've become pretty up to date with the epidemiology, natural history and treatment of this infection. However I have some questions for you.

(1)I did not have symptoms at all before the test, but upon taking the treatment, I began to feel some tingling and pain around my penis and urethra. Can treatment for this cause genital pain or is this just a anxiety type of reaction?(2) Since my unprotected encounter, I've had one other partner where we engaged in unprotected oral and protected vaginal sex. Could I have gotten trich from this encounter as I know that it is usually happens from unprotected sex? I would not expect it, especially knowing this person.(3)I know that it is very unlikely to get through non sexual means, but I have used a gym hot tub multiple times recently. Probably hard to say, but is this even a remote possibility in my case? I am confused because I would have thought I got it from my unprotected encounter, but she is negative.(4)Should I tell my most recent partner, considering it was protected? (5)Should I get another test post treatment? If so, when and should include any other tests? Sorry for the rambling and thank you!

H. Hunter Handsfield, MD

89 months ago

Welcome to the forum. Thanks for your question.

This is a first for me. In all my years providing STD services in clinics and on this forum, and for ~5 years since the nucleic acid amplification tests (NAATs) for trichomonas became widely available, yours is the very first in my experience in which a trich NAAT turned up positive after a single sexual exposure. All other positives in my experience were in men who were the regular partners of women known to have trich. But it just goes to show: Trichomoniasis is an STD, and you're the "beneficiary" of that. That said, the negative test in your recent new partner suggest you may have been infected before that event; and therefore that your regular partner may have it. Also, 3 days may be a bit soon for a new infection to show up with NAAT testing -- although there is no research on time to positive results, so reallly can't do more than speculate about it.

To your specific questions:

1) The large majority of trich infections in men are asymptomatic; and when symptoms occur, the main one is discharge from the penis, not tingling or pain. These symptoms are most suggestive of anxiety magnifying otherwise trivial symptoms or even normal body sensations. (I'll also point out that whenever a patient suspects his or her own symptoms have a psychological origin, usually s/he is right!)

2,4) Trichomonas is not known to infect the oral cavity, so the oral sex was no risk to your partner. The vaginal sex carried little or no risk, assuming condom use was correct and complete. But condoms aren't perfect, so can't say there was zero risk to your partner. Also, based on the information discussed above, it is possible you and your regular partner have been sharing a trich infection without knowing it. All things considered, I would recommend your regular partner be treated and, ideally, have her own NAAT test, preferably by vaginal swab.

3) Sex onlly. No relationship to hot tubs, towels, etc.

5) Single dose metronidazole (Flagyl) is about 90% effective -- not bad, but not perfect. Get retested in 3-4 weeks. As noted, there are no good data on timing, but DNA detectable by NAAT might persist after trich is killed. For chlamydia and gonorrhea, retesting is always delayed 3+ weeks. In the absence of precise data for trichomonas, 3-4 weeks makes sense.

I hope this information has been helpful. Best wishes and stay safe-- HHH, MD

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89 months ago

Hi Dr. Handsfield,

Thanks for your reply. I too was a bit confused when I received that result, especially after hearing about negative results from the partner I did not use a condom with. With my "regular" partner we have only had sex 3-4 times and a condom was used each time and correctly to the best of my knowledge. I have had no other additional partners during this time and had another negative test that I got routinely as recently as 4 months ago. Would you speculate that I was passed the infection from my regular partner even through the condom use as the likeliest possibility or is there some possibility of a false positive or other explanation? I know this is hard to say, I just am curious. Should I wait until retesting before entertaining the idea of protected sex with anyone new? You mentioned chlamydia and gonorrhea, should they be included in the retest even though were never positive? Any long term effects of this I should concern myself with, or can I safely put this in the rear view?

Thanks again!

H. Hunter Handsfield, MD

89 months ago

I had assumed you were in a longstanding relationship with your current partner, probably with unprotected sex. Since not, it seems unlikely she is the source of your infection, or that you have infected her. A false positive result may indeed be possible. The trich NAATs have been less well studied in men than women, and even now may not be FDA approved in men. So there is the possibility your test was falsely positive. OTOH, in general false pos NAATs are uncommon in general. Nevertheless, all things considreed, that might be the most likely explanation. At this juncture, I don't think you need to out of your way to assure your current partner be tested or treated. Trichomonas is not very hamful, with few if any important complications in either men or women -- more an inconvenience than an important health threat. (There are trich experts who might disagree with me on this, but that's the consensus among most STD experts.)

I see no reason for you to be restested for gonorrhea or chlamydia.

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