Acceptability and Feasibility of Longitudinal Sampling for Sexually Transmitted Enteric Infections in Gay, Bisexual, and Other Men Who Have Sex With Men (GBMSM): Prospective Cohort Pilot Study Conducted in 2022 in South East England.

Background: In the last 2 decades, there has been an increasing number of sexually transmissible enteric infection (STEI) outbreaks among gay, bisexual, or other men who have sex with men (GBMSM). There remain important gaps in our understanding of how STEI transmission is sustained that repeated collection of samples could help to address. Objective: This study aimed to assess the feasibility and acceptability of longitudinal samples and epidemiological data collection among GBMSM accessing sexual health services (SHS) through a prospective cohort study. Methods: GBMSM (≥16 years) accessing 2 SHS in Brighton and Sussex were recruited between May and October 2022. Participants provided an initial rectal swab and optional fecal sample and completed an online baseline questionnaire. Weekly follow-up questionnaires and rectal swabs were collected for a further 11 weeks. Sexually transmitted infection (STI) surveillance data were pseudonymously linked to provide additional clinical and demographic information. Selected participants were invited to take part in an optional one-to-one interview. We assessed the number completing study procedures, characteristics of those completing procedures and not, and representativeness of the study sample alongside facilitators and barriers from interviews. A chi-square test was used to compare groups. Results: Overall, 193 participants were recruited. Half (100/193, 51.8%) provided a baseline rectal swab, with a third (34/100, 34.0%) of them providing all 12 swabs. Alongside the baseline swab, 76.0% (76/100) provided the optional fecal sample. Just over a third (71/193, 36.8%) of participants completed a baseline questionnaire, with a fifth (15/71, 21.1%) providing all follow-up questionnaires. Interviews (n=21) found that participation was motivated by the feeling of giving something back for services received and a perceived indirect benefit to self. The study was generally accepted, with over half reflecting on the perceived ease of participation and relatively simple tasks that could be easily integrated into normal routine with an element of flexibility. Most participants were satisfied with the 12-week study length, and having a definitive end point aided the ability to assess if they would be able to participate. Barriers to completing the study procedures included not being aware of what was required, particularly for the follow-up questionnaires. Suggested improvements included concise and easier-to-read instructions, with a section to clearly list out the key procedures of the study. SMS text messaging reminders were sent, but these were seen with variable utility and interpreted in different ways (eg, personal or generic reminders or thank you messages). Conclusions: This study has provided evidence that longitudinal rectal swab sampling and data collection for research purposes are feasible and acceptable among GBMSM attending SHS. This provides an innovative way to address important knowledge gaps about STEI transmission, which will help inform public health measures for infection control. Tangible insights from this pilot can also inform the design of similar studies in other settings.