Why the differing opinions on Oral and Chlamydia?

[airflighter]

A couple weeks ago you relieved me of my fears of getting Chlamydia from receiving fellatio 4-5 months ago. You say that it just does not transmit that way.  Thank you.  But, now I'm simply intellectually curious about something and was willing to pay to know the answer.

Why is it that nearly all, if not all, other medical web sites (some good ones), disagree with this? They say it can be transmitted. Is it that it's a recent discovery that it cannot, and they are not up to date, or is it just that they are trying to scare people into (rightly) having safe sex?  I even saw a doc in Urology on this site suggest it could be transmitted by oral sex.

It appears from your position at the University that you are in the thick of it, obviously an expert, so I assume you to be correct. But intellectually, I'd just like to understand why there are not many saying what you are saying.  Thanks so much for your response.

If you know of another medical site or paper that supports your position, I'd be interested in reading it if you reference it.

(Also, I was just curious, long long can Chlamydia stay in one's system? That's another one that has lots of different answers).

[airflighter]

Thank you so much, both of you. It's in interesting topic indeed.

May I ask for some clarification?

1. I am a confused over Dr. Hook's comment "Even if it occurs, it is of no known consequence."  Could you explain what that means? Do you mean that because chlamydia does not exist in the throat?  

2. And when you stated the 500 people with 10% showing signs of chlamydia at other sites, does that mean that only 50 people had chlamydia and they all performed oral sex on their partner? Or is it 500?. I'm confused about this too? Sorry.

(FYI: By the way, I'm so focused on chlamydia because I now have some prostrate issues and I'd read that chlamydia can be a cause.  Don't know if the big G and S std's could be too. Regardless, Dr. Handsfield had mentioned in a earlier Q&A of mine that my 12 days of Keflex--not first choice I know--of 500 mg 3X a day was sufficient to kill those, combined with no symptoms until this most likely unrelated prostate stuff 4-5 months later. And I do have a newly discovered enlarged prostrate)

[H. Hunter Handsfield, M.D.]

I don't normally comment on Dr. Hook's replies or vice versa.  But this is an interesting issue and he will agree with me on this.

I suspect the main reason that so many sites either say directly or imply that oral sex is a risk for chlamydia is that the people writing the information make assumptions from gonorrhea.  At one level, this seems to make sense; chlamydia and gonorrhea have many parallels.  But there still are important differences between them, and those include a much lesser likelihood that chlamydia infects the throat and probably an even lower chance of oral to genital transmission.  A related factor is that the people who actually write the posted information often are generally trained health educators, not necessarily sophisticated STD experts.  Finally, such (mis)information can become self-sustaining.  If say a state health department says oral sex is a chlamydia risk, a local health department might just repeat the same message.

Dr. Hook correctly summarizes the data.  I will add that there is support from another kind of research.  Among men in STD clinics, the presence or absence of genital chlamydia is unrelated to their histories of recent fellatio.  By contrast, gonorrhea is corrleated with oral sex, especially in men who deny vaginal and anal intercourse.

HHH, MD

[Edward W Hook, MD]

I cannot comment on the origins of the information placed on other web sites. I can however comment on the published literature, as well as some unpublished work done as part of our own research.  I think to say that chlamydia is NEVER transmitted to the throat by oral sex is probable a little too strong.  It does. However this is so very rare as to allow experts such as Dr. Handsfield and I to say that, for all practical purposes, both that it never (perhaps we should say almost never) happens and that there is NO data to suggest that even in those very rare occasions when it occurs that it is of consequence for those who have it, either in terms of transmission to others or complications.  So how common is "hardly ever" - well in our studies of over 500 people who performed oral sex on a partner and in whom well over 10% had chlamydia at other sites, it happened once.  Remembering that our study was done among patients at high risk (they were in an STD Clinic, they had relatively high rates of chlamydia elsewhere), this translates effectively to "never" which we state rather than feed unjustified apprehensions.  Even if it occurs, it is of no known consequence.  No authoritative source recommends routine testing for chlamydia at the throat.  That said, I'm sure you can find others who would, just as you can find just about anything you want to if you look in the internet long enough.

How long can chlamydia persist in it's asymptomatic state? --no one knows for sure.  We do know that among persons with genital chlamydai who do not get treated for one reason or another, that after only 30 days, about 15-20% of people had "cleared" the infection by themselves, without antibiotics.  At one year, the number who have still not cleared is about 25%.  So, in answer to your question, it can certainly persist without symptoms for over a year.  As you can imagine, to get information such as what I've just reported to you, we have to have unusual situations in which infected persons do not come back for treatment despite efforts to encourage them to do so.  To formally study it would be unethical.

Interesting question, complicated answer.  Hope it helps.  EWH

[Edward W Hook, MD]

More Good Questions

1.  The major consequences of STDs relate to their ability to cause complications, their ability to increase risk for HIV acquisition and their ability to amplify the first two problems through transmission to others.  There is no evidence that chlamydia infection of the throat, even on those very rare occasions that they occur, contribute to any of these problems.   There is, of course, also emotional impact but this is more of a socially determined phenomenon than an actual health risk.

2.  In the STD well over 50 people had chlamydia (sorry, I do not remember the absolute number), none of whom had chlamydia only at the throat.  These data add to several other studies which looked hard for chlamydial throat infections and found almost none.  Taken together these studies all agree that throat infections are very, very rare and when present do little harm to those with the infection.  That we say this is not for a lack of looking.

Thanks for the questions.  Hope these answers help.  EWH