Impact of mass distribution of long-lasting insecticidal nets (LLINs) in Mozambique, 2011 to 2025: Retrospective and prospective modeling of child mortality and lives saved

Abstract

Background Malaria was the leading cause of post-neonatal deaths in Mozambique in 2017. The use of long-lasting insecticidal nets (LLINs) is recognized as one of the most effective ways to reduce malaria morbidity and mortality, especially in children. In 2015, Mozambique committed to the expansion of LLIN coverage nationwide, culminating in the first countrywide campaign in 2017, reaching 95% of registered households. Between 2012 and 2019, more than 34 million LLINs were distributed. No previous analyses have estimated changes in mortality attributable to the scale-up of LLINs, accounting for provincial differences in mortality rates and coverage of health interventions. Methods From 2012 to 2020, the population-based model NetCALC was used to predict provincial household LLIN coverage based upon the number of LLINs distributed annually. NetCALC also projected how many LLINs are needed to maintain universal coverage in 10 provinces from 2021 to 2025. Based upon the annual provincial coverage of LLINs, the Lives Saved Tool (LiST), a multi-cause mathematical model, estimated under-5 lives saved, and reductions in under-5 mortality attributable to LLIN expansion in 10 provinces of Mozambique between 2012 and 2020, and projected lives saved from 2021 to 2025 if universal coverage of LLINs is sustained. Results Results from the LiST models estimate that 64,470 child deaths were averted between 2012 and 2019. If currently planned quantities of LLINs are distributed in 2020, and universal coverage is maintained from 2021 to 2025, an additional 68,695 child deaths could be averted. From 2011 to 2020, the percent reduction in all-cause child mortality was 19.2%, from 114.5 per 1,000 to 93.2 per 1000 in the LLIN distribution model compared to 9.5% in the baseline model. If universal coverage continues through 2025, this reduction will be sustained. Conclusions LiST and NetCALC used together are useful in estimating lives saved and mortality in countries such as Mozambique where vital registration data to measure changes in mortality are not consistently available. Universal coverage of LLINs can save a substantial number of child lives and reduce child mortality in Mozambique but will require resource mobilization. Without continued investment, thousands of avoidable child deaths will occur.