[Question #5043] Chlamydia Positive Dr. Handsfield

77 months ago

Dr. Handsfield,

I am in a 9 year relationship with a woman I love. I made a mistake and slept with another women unprotected over the past 1.5 months. I have always tested clean and did so 2 mos ago for all STDS. I then slept with my gf several times after the clean test. Since the last time I slept with my gf, I slept with one women unprotected which I tested 5 days after and I received positive test for chlamydia via urine NAAT. Negative gonorrhea. I purposefully avoided sex with my gf since sleeping with the woman, however I did receive unprotected oral from my gf with swallow on 1 for sure possibly 2 occasions over this same time period after sleeping with the woman. No vaginal/anal with gf.

My conundrum is whether to tell my gf or whether she needs treatment. I have dated her a long time and would not want to lose her over something stupid like sex and my mistake. I did not know I was positive at the time and thought oral sex was safe sex according to established medhelp posts.

Should I continue sex with my gf as normal once I wait the 1 week for treatment and confirm negative test 3 weeks later? I am just unsure on her oral status. Discharge has started at 24 hours after Azithromycin administration so i'm sure im positive. I understand risk and statistics, however what are odds of transmitting positive penis to mouth with swallow on one/two isolated exposures. Is chance of her infection 1 in 10, or 1 in 10,000 for statistical consideration? Any long term worry?

H. Hunter Handsfield, MD

77 months ago

Welcome to the forum. Thanks for your question.

The crucial part of this question is exactly when you acquired your chlamydial infection. As you have surmised, the timing is consistent with the unprotected event (which presumably included vaginal sex) 5 days before your postiive test, which also is consisted with onset of symptoms about the same time, including just after treatment. But chlamydia testing in men without symptoms can miss some infections (up to 10% with urine testing), so it is possible you were infected longer and exposed your regular partner. I'll also point out an obvious fact, that when one member of a couple is having other partners, often the other is doing so as well. In other words, from my perspective (maybe not from yours), there's a chance you acquired your infection from your regular partner. I have no way to be confident either way, which is why if you were in my STD clinic, we would strongly recommend testing and treating both your partners.

But if I correctly understand the sequence of sexual exposures, your gf performed felllatio on you after you likely acquired the infection but before testing and treatment. Therefore, she is definitely at risk for oral infection. There are no data on the numerical risk; until the last few years, we thought oral chlamydia was very rare. More recent studies with more accurate tests show it's more common than previously believed, but no data at all exist on the per-exposure risk of transmission. But the consequences of oral infection may be a problem: recent research also shows that chlamydia can infect the gastrointestinal tract, and that oral sex may be how that happens. And intestinal chlamydia doesn't respond as well to treatment with azithromycin.

Bottom line: both your partners need treatment and therefore will have to be informed fully about the situation. Ideally both should also be tested at all potentially exposed sites, but treatment is the top priority. For your regular partner, it should be with doxycycline rather than azithromycin.

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

HHH, MD

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77 months ago

To answer your questions:

Yes had vaginally unprotected sex with new woman during acquisition and yes the timeline fits perfectly. I also had a previous test before the last in dec and was also negative at that time as well with no new partners. I don't believe my girlfriend was source or exposed based on that information but I recognize it is a possibility.

Yes only exposure to gf was 1 instance of fellatio prior to treatment.

I will advise her what happened and unfortunately realize the end of my relationship. Hard to swallow decade of great relationship lost for my own stupidity... I am at a loss.

I do have a few remaining questions about oral and GI Chlamydia to improve my understanding as I always thought oral was safe based on my previous research and it unfortunately affected my decision making process.

What are the long term complications due to oral chlamydia/GI? Since until recently chlamydia was estimated to be very rare for oral transmission up until now and not a serious concern. What happens or happened to all the past possibly active cases that were not tested/treated due this belief? Does the immune system likely take care of these? I have read that 50% of cases are estimated to be cured by the immune system within 12 mos. Is GI chlamydia also theorized to be the same way? Does the new information change testing and how is GI infection even measured?
I understand your position on not estimating numbers based on transmission rates that have not been formally studied. And I realize this information will probably never be known based on the ethical nature of this study. The only oral Chlamydia data I can find shows that existence of oral Chlamydia for random sampled patients at a clinic is about 1-2% however this is pre-existing cases only. Can it be inferred or projected from this information as well as based on your professional knowledge and experience that there is a general theoretical estimation of likelihood? Is this something that is highly likely, moderate, or likely less rare than originally thought but still rare?

Thank you.

H. Hunter Handsfield, MD

77 months ago

The entire topic of chlamydia and the GI tract is new and interesting. I'm going to take this opportunity for a blog-like reply that I can save in event of future similar questions.

For 20+ years it has been known that almost all mammalian species studied -- several of them -- and also birds and maybe some reptiles -- have their own indigenous chlamydia species, biologically similar to humans' Chlamydia trachomatis. In most or all cases the organism is primarily found in the GI tract. Not all experts believe it's an issue for humans, but others ask why we would be the only exception among all mammals studied so far -- which is my perspective. But it's only in the last 3-4 years that research into this has begun. There are no known complications of chlamydia involving the GI tract; if it's an issue, it's mostly as a reservoir without harm unless and until the organism finds its way to the genital tract. Rectal infection is quite common, but mostly in women, who can be infected either directly (anal sex) or probably by anal contamination with cervical/vaginal secretions; and gay men who have had receptive anal sex. It is also possible that rectal/GI colonization explains some cases of vaginal/cervical infection in women who deny any recent sex, i.e. contamination of the vaginal area from the rectum in someone who might have longstanding (years?) rectal/GI colonization. Whether oral infection leads to GI colonization that later can be detected in the rectum isn't yet known, although some researchers think this is a likely explanation for occasional rectal infections found in persons (usually women) who deny recent vaginal or anal sex.

The other aspect of this research concerns treatment. Animals' GI chlamydial infections are more reliably eradicated with tetracyclines (like doxycycline) than macrolide antibiotics (like azithromycin). And in humans, in the past 10 years we have increasingly strong data that azithromycin is less reliable for rectal chlamydia than doxycycline, which is why your gf should be treated with doxy following her oral exposure to you.

Genital chlamydia is typically cleared by the immune system within a year in nearly 100% of infected patients. However, those data are based on culture, and not the more sensitive DNA detection tests now normally used. There are no data at all on whether or how long GI colonization may be cleared without antibiotic treatment. But in animals, such GI colonization may continue indefinitely until treated with antibiotics.

As for transmission efficiency, I just can't give any numerical estimate except my best guess that the large majority of oral exposures to chlamydia do not result in oral/throat infection. But some clearly do. Transmission in the other direction, oral to genital, has never been reported and therefore probably is rare if it occurs at all. Using culture, among men with NGU whose only possible exposure was insertive fellatio, chlamydia is never found. Similar research using DNA testing is underway or being planned by several research groups, but no results have yet been reported. My bet is that oral to genital transmission will be found to be very infrequent, i.e. transmission efficiency very low. But only time will tell.

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77 months ago

Thank you Dr. Handsfield,

I have a few final questions to conclude my post here:

(1) How is Chlamydia of the throat/anus/GI tract currently being treated by cdc recommendation and the majority of doctors in practice? I know swabs exist however it seems the majority of doctors don't do them or if they do they may use poor swab technique or have the potential to miss the infection. Also, it would seem GI infection on the other hand would be difficult to even test for (Stool sample?). Is doxycycline given as a precautionary treatment without confirmed infection (due to difficulty of testing these sites) to handle this? If someone was exposed orally would they even swab or would they simply give doxycycline as a precaution?

(2) I would generalize (and from most people I asked about their std test procedures) that the vast majority of doctors simply test urine only and never consider oral/GI infection (or do in fact swab and possibly miss the infection) and treat genital infection only with Azithromycin.

Would Azithromycin still be effective for other sites (throat/GI) in majority of cases? I know doxycycline is most effective for oral/GI sites but would Azithromycin likely still be effective in the majority of cases (for the other exposure sites) as well? 80% and above? I have seen 80% through my searching but I am not sure if your expertise of the data says otherwise.

(3) With the increased prominence of oral sex recently I would think most patients would be positive orally/GI as well as genitally. Is there data that confirms this? And does this change the cdcs recommendation of future antibiotic preference?

I received treatment and informed my girlfriend and she will follow up with her doctor. We are now separated unfortunately. I still wonder to this day what the final implications of her exposure was. While researching chlamydia more I am finding very differing data on Chlamydia and GI implications. This collaborates your earlier discussion about the uncertainty of this issue and your blog post. I am even finding some data suggesting first chlamydia exposure orally/GI may even provide improved immunity to genital infections and be a good thing. It is still unclear. Such a difficult topic and I feel like I ended my relationship over a 1 in 1000 likelihood of transmission. I guess that's how it goes and was my own fault. It seems the research is in its infant stages and too early to draw conclusions.

Thank you for your time.

H. Hunter Handsfield, MD

77 months ago

1) Officially, either azithromycin 1.0 g or doxycycline 100 mg twice daily for 7 days. Because of the chance of GI tract colonization, some experts would prefer doxycycline. That's my view. Maybe someday we'll have more precise data for guidance.

2) Indeed, many physicians (mostly not STD experts) don't test at non-genital sites as often as they should, or take detailed sexual histories to guide testing. There are no known testing procedures or recommendations for GI infection other than a rectal swab. You're probably right that azithromycin usually would work. But so what? If it is, say, 90% effective, but doxy is 100% effective, why not just use doxy? Most likely that's where routine management is going.

3) It's a misperception that oral sex is all that much more common. That statement would have been true in, say, 1990. Oral-genital sex probably was less common before then, but probably not much change in its frequency in the last 15-20 years.

Most of the "differing data on chlamydia and GI implicaitons" probably are not actually different data, but different assumptions and interpretations of the very scant data that exist. All things considered, the most likely outcome as research progresses is that GI colonizaion with chlamydia is no big deal, except that rectal and other possible GI infections should be treated with doxycycline rather than azithromycin. In the long run, I see this as an interesting intellectual exercise, but not a big deal in clinical implications for most patients.

That concludes ths thread. I hope the discussion has been helpful.

HHH, MD

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