How Should STI Screening Adapt to Better Serve High-Risk Populations?
Sexually transmitted infections (STIs) are caused by various bacteria, viruses, and parasites, mainly spread through vaginal, anal, or oral sex. Some STIs can also be transmitted from mother to child during pregnancy, childbirth, or breastfeeding. There are curable infections like syphilis, gonorrhoea, chlamydia, and trichomoniasis, which respond well to antibiotics. However, viral STIs, such as herpes, are incurable but can be managed with treatment.
STIs can lead to serious long-term health issues if left untreated. Prevention through condom use, vaccinations, and early diagnosis is essential, but new challenges like emerging infections and antimicrobial resistance make controlling STIs increasingly difficult.
In South Africa, screening for sexually transmitted infections (STIs) among men who have sex with men (MSM) is not routinely available in the public sector, and current STI management guidelines do not include algorithms for screening or treatment of infections outside of typical genital areas (extragenital infections).
Men who have sex with men (MSM) and transgender women (TGW) are considered key populations (KP) because they are at increased risk of acquiring HIV and sexually transmitted infections (STIs). This is in part due to biological factors, engagement in high-risk sexual practices, and structural barriers to accessing healthcare services.
A recent national survey revealed that the majority of MSM, 86%, utilise the public healthcare system in which STIs are managed syndromically with a focus on urogenital symptoms only. However, the anatomical sites of infection among MSM include the oro-pharynx and rectum, with infections at these sites being largely asymptomatic.
This report summarises the first year of comprehensive STI surveillance among high-risk members of this key population from a single NGO partner site in Johannesburg.
Materials and Methods
The overall aim of this surveillance study was to determine the burden of asymptomatic extragenital STIs and examine the aetiologies of symptomatic male urethritis. In addition, we sought to monitor for N. gonorrhoeae resistance in culture-positive isolates as well as detect other emerging STI pathogens in high-risk MSM from Johannesburg.
A cross-sectional study of STI aetiologies among MSM attending the Engage Men’s Health (EMH) Clinic in Melville, Johannesburg, was conducted from 11 April to 15 September 2023. Eligible participants were: i) adult ( ≥ 18 years) men or transgender women (i.e., a patient registered as male at birth); ii) who reported sex (oral or anal) with another man in the past 3 months regardless of sex with women; iii) who were given information on the study by an NICD-appointed professional nurse; and iv) provided written consent to participate, including the long-term storage of samples for future research.
Oropharyngeal and rectal ESwab® (Copan Italia SpA, Brescia, Italy) specimens were collected from all participants. Endo-urethral ESwab® specimens were only collected from participants presenting with visible urethral discharge. In addition, a 10ml venous blood specimen was collected from each participant for serological testing.
All laboratory tests were performed at the Sexually Transmitted Infections (STI) reference laboratory, Centre for HIV and STIs, National Institute for Communicable Diseases/NHLS.
Results
A total of 131 MSM participated in the 2023 survey, of which 48 (37%) presented with urethral discharge at enrolment. Overall, the detection of STI pathogens at extra genital anatomical sites (pharynx and/or rectum) was common at 39% (51/131); that is, 41% (34/83) among MSM without urethral discharge and 35% (17/48) among participants presenting with urethral discharge at enrolment.
The overall prevalence of pharyngeal STI infections was below 2.5%. Neisseria gonorrhoeae was the predominant rectal pathogen in both subgroups, whilst anorectal infections with C. trachomatis (12.7% vs 4.3%) and M. genitalium (15.2% vs 4.3%) were higher among MSM without urethral discharge compared to those with visible urethral symptoms, although this did not reach significance. Most STIs at the rectal site were caused by a single agent, with co-infections with multiple pathogens accounting for only 1/16 (6.3%) and 5/34 (14.7%) of anorectal STIs in MSM with and without urethral discharge, respectively.
For a more in-depth look into this unique study, download the full article below.
