Clin Infect Dis. 2017 Jun 15;64(12):1705-1710.

High Proportion of Anorectal Chlamydia trachomatis and Neisseria gonorrhoeae After Routine Universal Urogenital and Anorectal Screening in Women Visiting the Sexually Transmitted Infection Clinic.

Geneviève A. F. S. van Liere, Nicole H. T. M. Dukers-Muijrers and Christian J. P. A. Hoebe

From Department of Sexual Health, Infectious Diseases and Environmental Health, South Limburg Public Health Service, Heerlen and the department of Medical Microbiology, School of Public Health and Primary Care, Maastricht University Medical Centre, the Netherlands.

Correspondence should be addressed to Dr. Geneviève van Liere Department of Sexual Health, Infectious Diseases and Environmental Health, South Limburg Public Health Service, Heerlen. E-mail:




Testing on indication of self-reported anal sex or symptoms is used to manage anorectal Chlamydia trachomatis (chlamydia) and Neisseria gonorrhoeae (gonorrhea) infections in women. Little is known about the impact of another testing strategy, routine universal anorectal screening with respect to chlamydia and gonorrhea prevalence and risk factors.


All women (n = 1012) aged ≥16 years attending our sexually transmitted infection clinic in 2015 were offered routine universal screening. In total, 19.5% (n = 185) of women had an indication (reported anal sex or symptoms), 72.5% (n = 689) did

not have an indication, and 8.0% (n = 76) had missing information on indication. Logistic regression analyses were used to identify determinants associated with anorectal chlamydia and gonorrhea.


Of all women who visited our clinic, 94% (n = 950) participated in the study. Overall anorectal chlamydia/gonorrhea positivity was 13.4% (n = 127)/1.3% (n = 12). Self-reported anal sex and anal symptoms were independently associated with anorectal

gonorrhea (odds ratios [ORs], 3.3 [95% confidence interval {CI}, 1.01–10.7] and 14.5 [95% CI, 2.8–75.0], respectively), but not with anorectal chlamydia. Of all anorectal chlamydia/gonorrhea cases, 72% (n = 92)/33% (n = 4) were diagnosed in women without an indication, of which 19% (n = 19)/0% (n = 0) were anorectal only. For women with missing indication, this was 7% (n = 9)/8% (n = 1) and 44% (n = 4)/100% (n = 1).


Anorectal screening in women without an indication is feasible and highly acceptable. Selective testing on indication could be an appropriate control strategy for anorectal gonorrhea, as few infections would be missed. In contrast, selective testing is a suboptimal control strategy for anorectal chlamydia, as we found a high prevalence in women both with and without indication for anorectal testing, along with a substantial amount of anorectal-only infections.



We aim to detect and effectively treat all STI in women visiting our STI clinic to halt individual sequelae and further transmission to others. International STI testing guidelines advocate anorectal testing on indication for women. This means only anorectal testing in women who self report receptive anal intercourse and/or symptoms. International guidelines advocate both azithromycin and doxycycline as equal first line treatment for anorectal chlamydia. In the Netherlands, doxycycline is the first line treatment for anorectal chlamydia, and azithromycin for oropharyngeal and urogenital infections. Studies report that the efficacy of azithromycin may be considerably lower compared to doxycycline for anorectal chlamydia (1).

In this study, we evaluated the current testing guidelines by implementing routine universal anorectal testing in over 1000 women visiting our STI clinic in 2015. A total of 94% of women took the self-collected anorectal swab, which means this method is feasible and acceptable among women.

Anorectal chlamydia positivity was 13.4% (n=127), anorectal gonorrhoea positivity was 1.3% (n=12). A total of 19.5% (n=185) women reported an indication, that is, receptive anal intercourse of anal symptoms, 72.5% (n=689) did not report an indication and for 8% (n=76) data on indication was missing.


Key messages 


  • Self reporting of receptive anal intercourse and anal symptoms were both not associated with anorectal chlamydia.
  • Testing on indication, as is advocated in the current international guidelines, would miss 72% (n=92) of anorectal chlamydia infections.
  • Of the missed anorectal chlamydia infections, 61% (n=78) could possibly be coincidentally treated with a urogenital chlamydia infection, in case azithromycin would be effective for anorectal chlamydia.
  • 19% (n=19) were rectal-only infections, these would not be tested and treated.


  • Self reporting of receptive anal intercourse and anal symptoms were both associated with anorectal gonorrhoea.
  • 5 out of 12 women with anorectal gonorrhoea did not report an indication for testing, but almost all of these women had a coincidental treatment for urogenital gonorrhoea, as this treatment is equal.
  • 1 (11%) woman with anorectal gonorrhoea had missing data on indication and no concurrent urogenital infection.

In conclusion, testing on indication of receptive anal intercourse and/or symptoms could be effective for anorectal gonorrhoea, but is suboptimal for anorectal chlamydia.



Figure 1. Urogenital and anorectal chlamydia and gonorrhoea prevalence in women with and without indication using routine universal anorectal screening.



Figure 2. The anatomic site distribution of chlamydia and gonorrhoea in women with and without indication using routine universal anorectal screening.



  1. The efficacy of azithromycin and doxycycline for the treatment of rectal chlamydia infection: a systematic review and meta-analysis. FYS Kong, SN Tabrizi, CK Fairley, LA Vodstrcil, WM Huston, M Chen, C Bradshaw, JS Hocking. Antimicrob Chemother 2015; 70: 1290–1297.