I recently undertook a full panel of std testing. I have the works swabs of my throat and anus along with urine and bloods taken. All were negative except for my anal swab that return postive for chlamydia which was a shock as I've not done anything anally and never had chlamydia to spread from one location to another? 

I am currently away and have just recieved the results and are seeking advice from my doctor but I am really confused and worried.

How accurate are anal swabs and could it be a false positive? 

The initial notification was that your question had been assigned to a moderator. Here is the response you were looking for.

Based on your username, probably you are male. If female, the rectum can become infected simply because of being so close to the vagina. But the rest of this reply assumes you're a guy, in which case this is an unusual situation -- but not unheard of. But why did you have rectal testing for chlamydia? Normally that would be done only in people who have experienced rectal sexual exposure to a partner, i.e. receptive anal intercourse. Did the provider who collected the specimen understand your sexual history? Did you request rectal testing? If so, why?

If indeed there has been no anal/rectal sexual exposure, then as you suggest it is possible your test was falsely positive. However, the standard chlamydia tests very rarely are falsely positive. While this cannot be ruled out, it's safest to assume you are infected. You should be treated with doxycycline for 7 days:  better safe than sorry.

Assuming it isn't a false positive, how could this happen? This has actually been an area of recent research interest. One possibility is that oral exposure could pass all the way through the intestine to show up as a positive result on anal/rectal testing. It probably is rare but may explain some situations like yours. But perhaps the research studies now underway will solve this dilemma.

The bottom line (pun intended!) is that you really needn't worry once treated as suggested above. You'll be easily cured with doxycycline and done with it.

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

HHH, MD

I've had testing over the past 12 months 3 monthly intervals and always negative. So I am definitely confused as to how it has come about as these include oral testing as well.

Could I have it genital and that test missed it and I passed it over to my anus during wiping or towel drying? Should I be worried about my heterosexual partners?

Genital infeciton in males cannot work itself over to the rectum. There is no reason to suspect your female partners have been at risk of catching chlamydia from you.

When all is said and done, your positive rectal test is a mystery that almost certainly will never be solved. Look at it as a curiosity, but once treated, nothing to be worried about.

You haven't said anything in response to my comments about treatment. I assume you have been in touch with a provider who has prescribed doxycycline for a week.