Résumé
Malaria was first confirmed in Comoros in 1923 by Jean Raynal (Raynal, 1928), who in 1925 was appointed by the French colonial government to investigate a fatal epidemic in Grande Comore. Since then, malaria has become an endemic disease in the Comoros archipelago. In 2023, a century later, malaria remains a major health problem that the authorities are committed to eradicate. The aim of this demonstration is to retrace the evolution of malaria epidemiology from 1923 to 2023 in order to understand its decline and maintenance in Comoros. Thus, World Health Statistical Yearbooks and WHO World Malaria Reports, as well as the databases of the National Malaria Control Program (PNLP-Comores) were consulted to compile a database of malaria cases from 1923 to 2023. Using both historical and more recent sources of population data, the annual incidence of malaria was calculated for the three islands of the Union of Comoros. In parallel, data on various malaria control measures implemented during this period were recorded and used to examine their effects on the malaria evolution trend. The malaria epidemic of 1923 to 1925 caused over 2,500 deaths on Grande Comore alone. Malaria incidence averaged over 3,307 cases per 100,000 inhabitants between 1955 and 1976, less than 2,410 cases between 1993 and 1999, and over 7,360 cases between 2004 and 2009. From 2010 to 2017, incidence declined from 15,074 cases to less than 323 cases per 100,000 inhabitants, a 94% of reduction. However, since 2018, there has been a resurgence of malaria cases in Grande Comore, with incidence exceeding 1,000 cases per 100,000 inhabitants. This study showed how malaria has evolved in Comoros over a century, characterizing the effects of the control measures implemented: indoor residual spraying, mass distribution of insecticide-impregnated mosquito nets, mass treatment with Artequick, and improved diagnosis, care and treatment of patients. Comoros has been classified as a country in the malaria elimination phase, but definitive elimination remains a major challenge.