Entomological effects of attractive targeted sugar bait station deployment in Western Zambia: vector surveillance findings from a two-arm cluster randomized phase III trial

• Published in: Malaria Journal
• Main Authors: Joseph Wagman, Benjamin Chanda, Javan Chanda, Kochelani Saili, Erica Orange, Patricia Mambo, Rayford Muyabe, Tresford Kaniki, Mwansa Mwenya, Mirabelle Ng’andu, Jimmy Sakala, Willy Ngulube, John Miller, Annie Arnzen, Kafula Silumbe, Gift Mwaanga, Limonty Simubali, Alice Mungo, Monicah M. Mburu, Edgar Simulundu, Brenda Mambwe, Racheal Kasaro, Conceptor Mulube, Mulenga Mwenda, Busiku Hamainza, Ruth A. Ashton, Thomas P. Eisele, Angela F. Harris, Julian Entwistle, Joshua Yukich, Laurence Slutsker, Thomas R. Burkot, Megan Littrell
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2024
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/s12936-024-05045-3; https://doaj.org/article/f7789bb5589847ed80ca5903e7a3d836

Abstract Background Attractive targeted sugar bait (ATSB) stations are a novel tool with potential to complement current approaches to malaria vector control. To assess the public health value of ATSB station deployment in areas of high coverage with standard vector control, a two-arm cluster-randomized controlled trial (cRCT) of Sarabi ATSB® stations (Westham Ltd., Hod-Hasharon, Israel) was conducted in Western Province, Zambia, a high-burden location were Anopheles funestus is the dominant vector. The trial included 70 clusters and was designed to measure the effect of ATSBs on case incidence and infection prevalence over two 7-month deployments. Reported here are results of the vector surveillance component of the study, conducted in a subset of 20 clusters and designed to provide entomological context to guide overall interpretation of trial findings. Methods Each month, 200 paired indoor-outdoor human landing catch (HLC) and 200 paired light trap (LT) collections were conducted to monitor An. funestus parity, abundance, biting rates, sporozoite prevalence, and entomological inoculation rates (EIR). Results During the study 20,337 female An. funestus were collected, 11,229 from control and 9,108 from intervention clusters. A subset of 3,131 HLC specimens were assessed for parity: The mean non-parous proportion was 23.0% (95% CI 18.2–28.7%, total n = 1477) in the control and 21.2% (95% CI 18.8–23.9%, total n = 1654) in the intervention arm, an OR = 1.05 (95% CI 0.82–1.34; p = 0.688). A non-significant reduction in LT abundance (RR = 0.65 [95% CI 0.30–1.40, p = 0.267]) was associated with ATSB deployment. HLC rates were highly variable, but model results indicate a similar non-significant trend with a RR = 0.68 (95%CI 0.22–2.00; p = 0.479). There were no effects on sporozoite prevalence or EIR. Conclusions Anopheles funestus parity did not differ across study arms, but ATSB deployment was associated with a non-significant 35% reduction in vector LT density, results that are consistent with the epidemiological ...