Cost and cost-effectiveness of indoor residual spraying with pirimiphos-methyl in a high malaria transmission district of Mozambique with high access to standard insecticide-treated nets

• Published in: Malaria Journal
• Main Authors: Sergi Alonso, Carlos J. Chaccour, Joseph Wagman, Baltazar Candrinho, Rodaly Muthoni, Abuchahama Saifodine, Francisco Saute, Molly Robertson, Rose Zulliger
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2021
• Subjects: Vector control; Indoor residual spraying; Insecticide-treated net; Economic evaluation; Mozambique; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic; Daly
• Online Access: https://doi.org/10.1186/s12936-021-03687-1; https://doaj.org/article/577e450b628f470bac17caca6bbdfd75

Abstract Background As malaria cases increase in some of the highest burden countries, more strategic deployment of new and proven interventions must be evaluated to meet global malaria reduction goals. Methods The cost and cost-effectiveness of indoor residual spraying (IRS) with pirimiphos-methyl (Actellic®300 CS) were assessed in a high transmission district (Mopeia) with high access to pyrethroid insecticide-treated nets (ITNs), compared to ITNs alone. The major mosquito vectors in the area were susceptible to primiphos-methyl, but resistant to pyrethoids. A decision analysis approach was followed to conduct deterministic and probabilistic sensitivity analyses in a theoretical cohort of 10,000 children under five years of age (U5) and 10,000 individuals of all ages, separately. Model parameters and distributions were based on prospectively collected cost and epidemiological data from a cluster-randomized control trial and a literature review. The primary analysis used health facility-malaria incidence, while community cohort incidence and cross-sectional prevalence rates were used in sensitivity analyses. Lifetime costs, malaria cases, deaths and disability-adjusted life-years (DALYs) were calculated to determine the incremental costs per DALY averted through IRS. Results The average IRS cost per person protected was US$8.26 and 51% of the cost was insecticide. IRS averted 46,609 (95% CI 46,570–46,646) uncomplicated and 242 (95% CI 241–243) severe lifetime cases in a theoretical children U5 cohort, yielding an incremental cost-effectiveness ratio (ICER) of US$400 (95% CI 399–402) per DALY averted. In the all-age cohort, the ICER was higher: US$1,860 (95% CI 1,852–1,868) per DALY averted. Deterministic and probabilistic results were consistent. When adding the community protective effect of IRS, the cost per person protected decreased (US$7.06) and IRS was highly cost-effective in children U5 (ICER = US$312) and cost-effective in individuals of all ages (ICER = US$1,431), compared to ITNs alone. Conclusion ...