Determinants of measles outbreak in the city of Kinshasa, Democratic Republic of the Congo in 2022: A case-control study

Introduction: Despite the immunization efforts carried out over the past five years, a resurgence of measles epidemics has occurred in the Democratic Republic of Congo since 2010. This study aimed to determine factors associated with the measles outbreak in the city of Kinshasa in 2022. Methods: This was an unmatched case-control study. A cluster-random sampling of 8 health zones out of 14 was carried out. The primary endpoint was the occurrence of measles. The cases consisted of patients confirmed positive at the national laboratory and probable cases with an epidemiological link between January and December 2022. The controls were the close neighbours not affected by measles. The logistic regression model was produced using Stata 17 software. Results: A total of 250 cases and 250 controls were recruited, with a median age (interquartile range) of 4(2-7) and 3(1-5) years respectively; 126(50.4%) cases and 83(33.2%) controls were not immunised against measles. The absence of contact with a measles case (aOR: 0.22, 95%CI: 0.13 - 0.37), the high socio-economic level (AOR: 0.26 95 % CI: 0.14 - 0.48) as well as the primary school level of education of mothers compared to no education (AOR: 0.23 95% CI: 0.09 - 0.60) were protective factors while non-immunization (aOR: 3.17, 95% CI: 1.93 - 5.22) and close living (aOR: 2.73, 95% CI: 1.29 - 5.73) were found to be risk factors of measles. Conclusion: This study highlighted the need to improve immunisation coverage, maternal education and the socio-economic level of households in order to prevent measles epidemics.