The epidemiology of malaria in four districts in southern Mozambique receiving indoor residual spray as part of a cross-border initiative

Abstract Background Imported malaria from southern Mozambique drives low levels of disease transmission in KwaZulu-Natal, South Africa. Therefore, the South African Department of Health funded implementation of indoor residual spraying (IRS) in Mozambiquan districts identified as sources of malaria infection for border communities in KwaZulu-Natal. IRS was initiated in districts of Guija, Inharrime, Panda and Zavala. To determine impact of spraying on malaria transmission in these districts, data relating to incidence and prevalence was collected before spraying (2018) and before the second round of spraying was completed (2023). Implementation of IRS was also monitored to ensure optimal spray coverage was achieved. Methods The study was a cross-sectional survey conducted in 6 sentinel sites in each of the four afore-mentioned districts, focusing on children 6 months to 95%) resulted in greater population protection. Conclusion The study revealed that IRS implementation decreased malaria prevalence in Inharrime and Panda but not in Guija and Zavala. To ensure that cross-border movement of people does not result in increased malaria transmission, targeting areas identified as source of infection in travelers is paramount to reaching elimination.