Introduction Symptom- and sexual history-based testing (testing on indication) for STD in (high risk) women has become part of standard operating procedures in STD clinics. However, little is known about alternative transmission routes for example by fingers and toys. We determined the proportion anorectal STD missed when applying testing on indication, such as STD due to alternative transmission routes.

Methods All women attending our STD clinic (consults: n = 395) [from May 2012–December 2012] were routinely tested for anorectal and urogenital Chlamydia trachomatis (Ct) and Neisseria gonorrhoeae (Ng) infections. Data were collected on demographics, anal symptoms, anal sex with casual/steady partner(s) and anal use of fingers and/or toys. We compared anorectal STD (Ct and/or Ng) prevalence between 3 groups of women: with indication (self reported anal symptoms and/or anal sex), without indication (no symptoms, no anal sex, no fingers/toys) and without indication but with self reported anal use of fingers/toys. Enrollment in the study is ongoing.

Results In total, 395 consults were included by 380 females. Overall prevalence of anorectal STD was 7.8% (n = 31). Of all consults, 31% (n = 122) had indication for anal testing, 60% (n = 237) no indication and 9% (N = 36) only used fingers/toys. Prevalence was 8.2% (10/122) with indication, 8.0% (19/237, P = 0.95) without indication and 5.6% (2/36, P = 0.61) without indication with use of fingers/toys. Testing on indication only would have missed 68% of all detected anorectal STD (21/31). Multiple infection (vaginal and anorectal) was present in all but one (with indication).

Discussion Large part of anorectal STD are missed in STD clinics, this was partly associated with alternative transmission routes. Also autoinoculation may be possible, all missed anorectal infections coincided with urogenital STD. However, treating urogenital Ct does not automatically imply appropriate co-treatment of anorectal Ct, since there is current debate on treatment of extragenital Ct.