[Question #2280] STD window periods

44 months ago

Hi there.  I am a Canadian female. I have recently been tested for chlamydia and gonorrhea with a swab using NAAT PCR.  My new partner is getting these performed as well, by urine, as he is male.  I have read different window periods for these tests.  I have a couple questions. 


1.  Is 10 days a sufficient window period for Chlamydia and Gonorrhea using NAAT PCR or should a person wait longer? 

2.  As well, here in Canada the routine STD tests include chlamydia, gonorrhea, HIV, HEP B and C and Syphilis.  I have recently heard of something called Trichomoniasis, an STI, but doctors do not routinely test for it.  Is this picked up in the NAAT PCR test performed for Chlamydia and Gonorrhea or does it have to be specified on a requisition? I am just wondering as it is never mentioned or added to requisitions or talked about. 

Thanks so much for your help.  I love your site.  It is always very helpful.


H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
44 months ago
Welcome back to the forum. Thanks for your kind comments about our services.

Trichomonas is the most common of all STDs, second only to HPV. However, serious outcomes are infrequent; from a public health perspective, it's not nearly as important as chlamydia or gonorrhea. Although there is controversy about it, including whether accurate testing (i.e. NAAT) should be more routine than it is, in general it is not a serious health threat. Having trich elevates the chance of catching HIV if exposed, but this is a minor factor in HIV prevention in industrialized countries.

To your questions:

1) The NAATs for gonorrhea and chlamydia are believed to always be positive within 2-5 days after exposure (shorter for gonorrhea, longer for chlamydia). For sure there is no need to wait longer than 5 days or so, and 10 days gives an even greater margin of safety.

2) For the reasons above, few STD clinics and public health agencies test patients routinely for Trichomonas. This is changing with the development of NAATs for trich. But most public health agencies consider it a low priority compared with other STDs. The main role for trich testing is when women have otherwise unexplained vaginal discharge. The whole business is controversial: some experts believe trich NAATs should be routine, but at this point most don't consider it essential. In any case, trichomonas testing must be specified; it won't be detected if testing is done only for gonorrhea and chlamydia.

I hope this information is helpful. Let me know if anything isn't clear.

HHH, MD
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44 months ago
Thanks so much.  Does trich clear up on its own eventually if one does have it? I don't have symptoms so may not worry about it. What is the window period for trich?  Thanks again! 
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
44 months ago
There's been no research on window period for trichomonas NAAT. There's really not been any on gonorrhea or chlamydia either -- advice about it is based primarily on knowledge of the growth rate of these germs after inoculation and the biology of the tests. (It's the difference in bacterial growth rates that dictates common advice about a NAAT window of 2-3 days for gonorrhea and around 5 days for chlamydia.) For trichomonas, I would be confident the test is reliable any time about 7 days after exposure.

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44 months ago
Thanks so much. Does trich eventually clear itself up if people don't know they have it and don't treat it? 
44 months ago
HI there. Just following up on my last question to this thread (I posted it a week ago) to see when it might be answered. Thanks so much. 
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
44 months ago
Oops -- sorry I missed the last follow-up question.

The natural course of untreated trichomoniasis has never been formally studied. We know that some women have trich diagnosed despite having had no sexual exposures at all for many years, and these are felt to be from longstanding infection that never cleared up. However, it might be a minority, maybe quite a small minority, of all women who acquire the infection; in other words, most infections may clear up with time. There are even fewer data in men, but most experts believe that such longstanding infections are less common in men than women. But beyond that, we just don't know. (However, when trichomoniasis first appears in a monogamous couple, we advise that because it's sexually transmitted, they should speak with their spouse or partner about the possibility of outside sexual experiences. However, if that is believed to be unlikely, we do not press the point -- quite different than how we counsel couples with gonorrhea, chlamydia or syphliis, for example.

Because of the prior delay, I'll leave this thread open for another round of comment and reply if anything remains unclear. Apologies again for the delayed response.

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44 months ago
No about the delay. I may request the test when I have my next physical/Pap just to be sure. Both my partner and I are negatibe for everything else. If I were to be positive for trick,  would he need to be treated too? Thanks again!
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
44 months ago
If you are without symptoms, I agree there is no need for testing now. You certainly could request testing next time you have a routine health care visit. If so, be sure to ask for the DNA test. The older but still commonly used microscopic test misses most infections, especially in absence of symptoms. If you ever have a positive result, your partenr also will need treatment.

Best wishes and stay safe.
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