Factors associated with the sexual transmission of Strongyloides stercoralis in men who have sex with men: A systematic review.

Strongyloides stercoralis is a parasitic worm with a complex life cycle and can cause significant morbidity, including a proctocolitis and life-threatening hyperinfection syndrome. Limited reports from non-endemic areas, including in men who have sex with men (MSM), suggest sexual transmission of S. stercoralis. In this systematic review of the published literature, we aimed to explore the associated factors of S. stercoralis in MSM. We systematically searched three bibliographical databases (MEDLINE, CINAHL and EMBASE) up to November 2022. We used a two-stage process to assess eligibility: the primary author conducted an initial screen of abstracts, and then three authors conducted independent full manuscripts to determine the final eligible manuscripts. We only included manuscripts written in English that contained data on specific factors associated with sexual transmission in MSM. We used the STROBE checklist to assess the risk of bias and synthesized the narrative data using the SWiM method. Seven manuscripts were eligible for this review (four case reports, one case series, one cross-sectional study and one experimental study), which included 22 individuals from Europe and the Americas. From these studies, S. stercoralis in MSM was associated with living with HIV (including having a low CD4 count and not using antiretrovirals), having a concomitant sexually transmitted infection (Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum and hepatitis C) and a concomitant (sexually transmitted) protozoal infection (Entamoeba histolytica, Giardia lamblia), travel to the S. stercoralis endemic area, multiple sexual partners from endemic areas, oro-anal sexual contact and chemsex. Although limited by the number of cases in the literature, we have highlighted some possible biological and behavioural risk factors associated with the sexual transmission of S. stercoralis in MSM that could be used to both target future research and S. stercoralis public health control interventions.

Factors and presenting symptoms associated with intestinal spirochaetosis in men who have sex with men: A systematic review.

The transmission dynamics and presenting symptoms of intestinal spirochaetosis (Brachyspira pilosicoli, Brachyspira aalborgi) are poorly understood but is seen more frequently in men who have sex with men (MSM) where sexual transmission may occur. We aimed to systemically review the literature to define the factors and presenting symptoms associated with intestinal spirochaetosis in MSM. We systematically searched three bibliographical databases (MEDLINE, EMBASE and Scopus) for manuscripts written in English up to November 2022. The primary author conducted an initial screen and three authors conducted independent reviews to determine the final eligible manuscripts. We only included manuscripts where there were specific data on factors and presenting symptoms associated with intestinal spirochaetosis in MSM. Fifteen manuscripts published between 1981 and 2022 met the inclusion criteria that included 188 MSM. Sexually transmitted intestinal spirochaetosis in MSM was associated with-living with HIV (including having a low CD4 count <200 mm3), having a concomitant sexually transmitted infection, a history of a sexually transmitted infection, co-infection with intestinal parasites; and sexual behaviour including oro-anal sexual contact, oro-genital contact, fisting, condom-less anal sex, receptive anal sex, multiple non-regular sexual partners and increased number of lifetime sexual partners. The presenting symptoms of MSM with intestinal spirochaetosis were diarrhoea, abdominal pain, constitutional symptoms and proctitis, including rectal pain, rectal bleeding rectal discharge, flatulence and tenesmus. We have highlighted some biological and behavioural factors and presenting symptoms associated with intestinal spirochaetosis in MSM which provide insight for clinicians, guidelines and future public health control strategies.