Rectal Chlamydia in heterosexual women: more questions than answers

The aim of this study was to observe the proportion of concurrent rectal Chlamydia (RCt) infection in women who have cervical Chlamydia (CCt) and to observe whether there was any correlation with receptive anal intercourse (RAI). Untreated CCt-positive women were invited to take part. Women chose either to have a physician-collected or self-taken rectal swab. Treatment was then commenced. 17 samples were physician-collected and 80 were self-collected. 75/97 (77.3%, 95% Confidence Interval [95%CI] 69.0-85.7%) were RCt positive. 25/97 (25.8%, 95%CI 17.1-34.5%) reported RAI. There was no difference in the positivity rate whether RAI was reported (80%) or not (76%) (P = 0.71); or whether swabs were physician-collected (65%) or self-taken (80%) (P = 0.17). Only one of those with RCt reported rectal symptoms. One woman had concurrent gonococcal infection. 34/97 (35%) had a history of past sexually transmitted infections. Verified contact attendance was 0.52 and 72% of verified contacts were Chlamydia positive. Reported RAI may not be helpful in guiding RCt testing. RCt infection in women may be more prevalent than previously thought. We do not know whether RCt infections are clinically significant or whether they may act as a reservoir for re-infection. RCt infections in women require further study.