Chlamydia is the most commonly reported infectious disease in the U.S., with over a million cases reported to the CDC annually. In reality, many cases of chlamydia are undiagnosed and unreported, so the true number of new cases each year (known as “incidence”) is probably closer to 3 million.

This bacterial infection is especially common in young women and is also common in young men. Sexually active adults with multiple sex partners and those who do not use condoms regularly also have increased rates of infection. Usually there are no tell-tale signs nor symptoms of infection to let you know, so you were smart to get tested. In fact, it’s recommended that all sexually active females under age 25 be tested each year for chlamydia.

We now have very accurate swab and urine tests for chlamydia using Nucleic Acid Amplification Technology (NAAT). However, a urine test will only detect chlamydia infection of the urethra or genital tract. To check for chlamydia infection in someone who has had receptive anal intercourse, a swab sample must be taken from the rectum which can be done easily and with little or no discomfort. The same NAAT test can be used to test this swab and tell you if you have a rectal infection. A different swab can also be used to test the throat to see if there is a chlamydia infection due to oral sex if you have had that exposure as well.

It can be hard, I know, but it would be a good idea to let your health care providers know you’ve had anal sex and/or oral sex (believe me, you won’t be the first to tell them that!) so additional tests can be ordered. Also, an HIV test is always a good idea for anyone who’s sexually active, for example.

–Gary Richwald, MD, MPH