Cost of community-led larval source management and house improvement for malaria control: a cost analysis within a cluster-randomized trial in a rural district in Malawi

Abstract Background House improvement (HI) to prevent mosquito house entry, and larval source management (LSM) targeting aquatic stages development into adult forms, are promising complementary interventions current malaria vector control strategies. Lack of evidence on costs cost-effectiveness community-led implementation HI LSM has hindered wide-scale adoption. This study presents an incremental cost analysis LSM, in a cluster-randomized, factorial design trial, addition standard national rural area (25,000 people), southern Malawi. Methods In the comprised draining, filling, Bacillus thuringiensis israelensis- based larviciding, while (henceforth HI) involved closing eaves gaps walls, screening windows/ventilation spaces with wire mesh, doorway modifications. Communities implemented all interventions. Costs were estimated retrospectively using ‘ingredients approach’, combining ‘bottom-up’ ‘top-down approaches’, from societal perspective. To estimate independently implementing each intervention arm, resources shared between trial arms (e.g. overheads) allocated consuming arm proxies developed share resource input quantities consumed. Incremental (in 2017 US$) presented for HI-only, LSM-only + arms. sensitivity analyses, effect varying important inputs was explored. Results The total economic programme $626,152. HI, as $27.04, $25.06 $33.44, per person year, respectively. Project staff, transport labour costs, but not larvicide or material, major drivers across sensitive changes staff population covered. Conclusions high compared previous studies. Several factors, including design, year-round low human density could explain costs. necessitated use allocate arms, which limits generalizability where different designs used. Nevertheless, may inform planners similar packages is known. Trial registration Not applicable. original registered Pan African Clinical Trials Registry 3 March 2016, number PACTR201604001501493