Targeting community-level drivers of antimicrobial resistance in sub-Saharan Africa:: the effect of a community-based intervention bundle on household transmission of Extended Spectrum Beta-lactamase-producing E. coli in rural Burkina Faso - a cluster randomised trial

Abstract

Background: In sub-Saharan Africa (sSA), invasive antimicrobial-resistant infections often originate from community-level acquisition. We assessed whether a behavioural intervention bundle targeting sub-optimal antibiotic use and hygiene practices reduced household-level acquisition of extended-spectrum beta-lactamase-producing E. coli (ESBL-E). Methods: We conducted a cluster-randomised controlled trial in 22 village clusters in Nanoro district, Burkina Faso. We enrolled 12 randomly selected households per cluster to assess intervention impact on ESBL-E household-transmission. The intervention comprised three rounds at three-month intervals and combined WHO AWaRe-based educational feedback for formal and informal medicine providers with a community-wide WASH and antibiotic-use behaviour change campaign. Consenting household members provided stool samples before, during, and after intervention rollout, alongside a pre-post household WASH survey. We estimated intervention effects on ESBL-E acquisition using Bayesian Markov models. Cox frailty models assessed associations between WASH exposures and acquisition. ClinicalTrials.gov, NCT05378880. Findings: Between Oct 11, 2022, and Feb 19, 2024, 1203 individuals were enrolled. At baseline, 56.6% (342/604) of control and 47.2% (283/599) of intervention household members were colonised. Pre-intervention acquisition incidence was 3.8 per 100 person-days (95% credible interval [CrI] 2.0-9.9) in the intervention group and 3.5 (95% CrI 1.8-9.6) in the control group. The intervention did not change the risk of ESBL-E acquisition in months 1-6 (hazard ratio [HR] 1.02, 95% CrI 0.78-1.31), while we estimated a reduction in ESBL-E acquisition from months 6-9 (HR 0.82, 95% CrI 0.56-1.14). Acquisition risk was higher in the rainy season (peak HR 1.73, 95% CI 1.49-2.00), while improved sanitation was associated with lower risk (HR 0.77, 95% CI 0.59-1.00). Interpretation: Findings, though inconclusive, were consistent with a modest intervention-related reduction in ESBL-E incidence. Higher acquisition rates associated with the rainy season and poor sanitation highlight the need to tackle environmental drivers of AMR transmission in addition to antibiotic use in rural sSA.