Soil-Transmitted Helminths Surveillance in Benin: A Mixed-Methods Analysis of Factors influencing Participation in Longitudinal STH Surveillance Activities

Abstract

Background: Ongoing research aims to determine the feasibility of interrupting transmission of soil-transmitted helminths (STH) via intensive approaches to deworming, including community-wide mass drug administration (MDA). Transitioning from a policy of STH control to transmission interruption will require rethinking existing STH surveillance protocols. Surveillance will be crucial for identifying priority areas for community-wide MDA, monitoring implementation, and verifying elimination. Although broad participation in surveillance activities is necessary to accurately estimate STH prevalence, minimal research has been conducted to investigate drivers of participation in stool-based surveillance. Methods: This mixed-methods exploratory sequential study took place in Com̩, Benin in association with the DeWorm3 Project. Six focus group discussions (FGD) were conducted with a sample of individuals who were invited to participate in annual stool surveillance as part of DeWorm3 activities. Quota sampling was used to ensure respondents included both people who provided a stool sample at baseline and people who did not. Respondents were asked about reasons they chose to participate in STH surveillance. Thematic analysis was used to identify drivers of participation and inform the quantitative analysis. Backwards stepwise model building was used to identify correlates of participation in baseline stool sampling. The influence of twelve variables on participation were considered based on existing literature and a hypothesis-driven conceptual framework developed from qualitative findings. A mixed-effects logistic regression model was built, with study cluster included as a random effect. Odds ratios and corresponding 95% confidence intervals are reported. Qualitative and quantitative findings were merged for interpretation. Results: Among the 7,039 individuals invited to participate in baseline stool surveillance, the refusal rate was 8.14%. Cluster-level refusal rates ranged from 0.6% to 20%. Qualitative themes indicate that drivers of participation include: community members weighing community-level benefits against individual-level risks, circulating rumors about misuse of stool samples, interpersonal communication with field agents, and cultural norms around handling adult feces. Recommendations to improve surveillance activities focused on communication and community engagement strategies. The quantitative analysis showed school-aged children were significantly more likely to provide a stool sample than adults (OR:1.44, CI:1.13 Р1.83), a finding that converged with the qualitative results. Individuals from areas in the highest quartile of population density were less likely to participate (OR: 0.58, CI: 0.40-0.86), which aligned with qualitative findings about circulating rumors. Several variables linked to community-affinity aligned with qualitative results; residing mainly in the community (OR: 2.76, CI:1.51 Р5.03) and having lived in the community for more than 10 years (OR: 1.31, CI: 0.87-1.85) increased likelihood of participation. Conclusion: This study found that certain individuals are more likely to participate in STH surveillance activities than others, including children, individuals in rural areas, long-term residents in the community, and those perceiving their families to be at risk for STH. If STH surveillance is intensified for the purposes of transmission-elimination programming, programs will need to reimagine how STH surveillance is conducted to address community concerns and ensure that no subpopulations are inadvertently excluded from surveillance data. Otherwise, programs could misidentify priority areas for MDA implementation or bias transmission verification data.