Rectal gonorrhoea and chlamydia among men who have sex with men in coastal Kenya.

Caroline J Ngetsa,Alex Thiong'O,Elizabeth Wahome,Grace Mwashigadi,John Mwambi,Margaret W Muturi,Nelson C Menza,Susan M Graham,Clara Karani,Peter M Mugo,Eduard J Sanders,Marc W Heymann

doi:10.12688/wellcomeopenres.15217.1

Abstract

Background: Men who have sex with men (MSM) experience a high burden of Chlamydia trachomatis (CT) and Neisseria gonorrhoea (NG) infections. These remain largely undiagnosed in the context of syndromic treatment. In Kenya, prevalence of rectal CT and NG infection and NG antimicrobial sensitivity are poorly described. Methods: MSM who reported receptive anal intercourse (RAI) were recruited from an ongoing human immunodeficiency virus acquisition and treatment study in coastal Kenya in 2016-2017. Rectal swabs were collected at two time points 6 months apart to estimate prevalence of CT/NG using a molecular point-of-care assay. Participants positive for CT or NG were treated according to national guidelines. NG culture and antimicrobial susceptibility testing was performed. Participant and risk behaviour characteristics were collected and association with baseline CT/NG prevalence was assessed by multivariable regression analysis. Results: Prevalence of CT/NG in 104 MSM was 21.2% (CT 13.5%, NG 9.6%, dual infection 1.9%) at baseline and 25% in 84 MSM at follow-up (CT 14.3%, NG 14.3%, dual infection 3.6%). Most CT/NG positive participants were asymptomatic: 95.5% at baseline and 100% at follow-up. CT/NG infection was associated with being paid for sex (aOR=6.2, 95%CI (1.7-22.9)) and being in formal employment (aOR=7.5, 95%CI (1.14-49.2)). Six NG isolates were obtained at follow-up; all isolates were susceptible to ceftriaxone and cefixime (1 st line treatment for NG) and all were resistant to penicillin, tetracycline and ciprofloxacin. Conclusions: The high prevalence of asymptomatic rectal CT and NG in MSM reporting RAI demonstrates the need for frequent screening or presumptive treatment. MSM who were paid for sex or had formal employment were more likely to be infected with CT/NG, suggesting increased risk behaviour during transactional sex. Antimicrobial susceptibility results suggest that current antibiotic choices in Kenya are appropriate for NG treatment.

Highlights

Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections are curable sexually transmitted infections (STIs) that can have distressing symptoms and complications, though a large proportion remains asymptomatic[1]
Participant characteristics are described in full in Prevalence of CT/NG At baseline, 22 (21.2%, 95% CI 13.8-30.3%) of the 104 Men who have sex with men (MSM) who took part in the study tested positive for CT and/or NG; 10 had NG (9.6%) and 14 had CT (13.5%)- 2 (1.9%) had dual infection
The prevalence of CT and/or NG infection was associated with receiving payment for sex [adjusted odds ratio=6.2, 95% CI (1.7-22.9)] and being in formal employment [aOR=7.5, 95% CI (1.1-49.2)] on multivariable logistic regression (Table 1), in a model controlling for age, having sex with men only or both men and women (MSME or MSMW, respectively), employment status and receiving payment for sex in the previous three months

Summary

Introduction

Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections are curable sexually transmitted infections (STIs) that can have distressing symptoms and complications, though a large proportion remains asymptomatic[1]. Men who have sex with men (MSM) are a key population with regards to transmission of STIs. Prevalence of rectal CT and NG infections has ranged as high as 21.7%-27.2% and 13.8%-25.4%, respectively in Italian and Thai MSM communities[3,4]. In Kenya, we have estimated the prevalence of rectal CT and/or NG to be 11.6% in a small sample of 43 human immunodeficiency virus (HIV)-negative adult MSM in the coastal region[10] and 5.2% in HIV-positive and HIV-negative MSM over the age of 18 in the western part of the country[11]. Men who have sex with men (MSM) have a higher prevalence of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections compared to the rest of the population, often remaining undiagnosed. Most CT/NG positive participants were asymptomatic: 95.5% at baseline and 100% at

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