Abstract
Background
Attractive Targeted Sugar Baits (ATSBs) are a potential addition to the integrated vector management strategy against malaria. ATSB stations utilize the attract and kill method to control mosquitoes. Each ATSB station contains a sugar bait laced with an ingestion toxicant. This study measured the duration of physical integrity of the ATSB Sarabi v1.2 station used in western Zambia as part of a Phase III cluster randomized control trial.
Methods
ATSB stations were installed on external walls of 304 sleeping structures, in 206 households (10–11 per cluster within 20 clusters). Monthly visits were made to assess for the presence and condition the ATSB stations from November 2022-June 2023. A rolling cohort approach was used, whereby newly installed, and replacement ATSB stations were included in the study. Information on structure construction and location of ATSB stations on walls was collected. Median ATSB survival and associated factors were analyzed with Kaplan-Meier curves and Cox-Proportional hazard models, respectively.
Results
Including replacements, a total of 1107 ATSB stations were installed across 304 sleeping structures and 5696 ATSB-visits were made. Common types of damage observed were holes/tears, mold, and leakage of bait. While the median survival time for the ATSB stations was five months (149 days) for all stations in the study, the median survival time was longer than the transmission season for stations installed in locations well protected by the roof (> 218 days). ATSB station survival was longer when installed on structures with thatched roofs compared to iron sheet roofs (Hazard Ratio 0.37, 95% confidence interval 0.26–0.47, p < 0.001), and where there was ‘excellent protection’ (HR = 0.36, 95% CI 0.25–0.49, p < 0.001), compared to ‘no protection’.
Conclusions
Study results suggest that the majority of Sarabi v1.2 ATSB stations deployed in this setting will remain intact for a 7-month seasonal deployment period if stations are installed in locations protected from rain and wind such as underneath a thatched roof. Further research is needed to understand factors that influence the physical integrity of ATSB stations in addition to those observed in this study.