Changes in Malaria Patterns in Comoros from 2010 to 2021: A Comparative Study with Sub-Saharan Africa.

Background: Recent setbacks in malaria control in Comoros demand a reassessment of its evolving epidemiology.

Methods: Using the Global Burden of Disease (GBD) Study 2021 data, we analyzed malaria trends from 2010 to 2021, stratified by sex. We quantified the contributions of demographic and epidemiological factors to these trends and identified risk factors for malaria-related disability-adjusted life years (DALYs).

Results: From 2010 to 2021, malaria cases, deaths, and DALYs in Comoros fell by -90.22%, -94.44%, and -94.88%; and the corresponding age-standardized rates declined with EAPCs of -18.70% (95% CI: -33.77 to -0.20), -23.89% (95% CI: -36.58 to -8.66), and -24.49% (95% CI: -36.88 to -9.66), with steeper declines in males. Nevertheless, all indicators increased in 2018 and again in 2021. In sub-Saharan Africa, only cases increased, while other metrics declined slightly. In Comoros, incidence shifted mainly to adults ≥25 years, unlike sub-Saharan Africa, where children < 5 years were most affected. Population growth drove increases in cases, deaths and DALYs, whereas epidemiological shifts had the opposite effect. Child underweight was the leading risk factor for malaria DALYs.

Conclusions: Existing interventions can achieve malaria control in Comoros; however, rebounds in 2018 and 2021 highlight the need to identify and address drivers of resurgence.