Deployment of Attractive Targeted Sugar Baits in Western Zambia: installation, monitoring, removal, and disposal procedures during a Phase III cluster randomized control trial.

Abstract

Abstract Background Attractive Targeted Sugar Baits (ATSBs) offer a complementary vector control strategy to interventions targeting blood feeding or larval control by attacking the sugar feeding behavior of adult mosquitoes using an attract-and-kill approach. This novel paradigm has the potential to combat the challenges of both physiological and behavioral resistance to contact insecticides and other sources of residual malaria transmission. Western Zambia was the first location to receive and deploy ATSB Sarabi version 1.2 stations in a Phase III cluster randomized control trial. This paper describes ATSB station installation, monitoring, removal, and disposal, quantifies ATSB station use and coverage, and reports major reasons for ATSB station replacement, as implemented in the Zambia trial setting. Methods ATSB stations were deployed during two annual transmission seasons, through scheduled installation and removal campaigns. During deployment, monitoring was conducted per protocol to maintain high coverage of the ATSB stations in good condition. Routine monitoring visits during the trial captured details on ATSB station damage necessitating replacement following pre-defined replacement criteria. Annual cross-sectional household surveys measured ATSB station coverage during peak malaria transmission. Results A total of 67,945 ATSB stations were installed in Year 1 (41,695 ATSB stations initially installed + 26,250 ATSB stations installed during monitoring) and 69,494 ATSB stations were installed in Year 2 (41,982 ATSB stations initially installed + 27,512 ATSB stations installed during monitoring) across 35 intervention clusters to maintain high coverage of two ATSB stations in good condition per eligible household structure. The primary reasons for ATSB station replacement due to damage were holes/tears and presence of mold. Cross-sectional household surveys documented high coverage of ATSB stations across Year 1 and Year 2 with 93.1% of eligible structures having ≥ 2 ATSB stations in any condition. Discussion ATSB station deployment and monitoring efforts were conducted in the context of a controlled cRCT to assess potential product efficacy. Damage to ATSB stations during deployment required replacement of a subset of stations. High coverage of eligible structures was maintained over the 2-year study despite replacement requirements. Additional research is needed to better understand the impact of damage on ATSB station effectiveness under programmatic conditions, including thresholds of threats to physical integrity and biological deterioration on product efficacy. Conclusions Optimizing ATSB stations to address causes of damage and conducting implementation research to inform optimal delivery will be important to facilitate cost-effective large-scale deployment of ATSB stations.