Measles trend in Gabon: Insight from 18 years of surveillance data.

Measles is a vaccine-preventable infection that can lead to serious illness and death. The delayed implementation of the World Health Organization (WHO)-recommended two doses of measles-containing vaccine (MCV1 and MCV2) and immunity gaps compromise the effort to elimination. Eighteen years (2006-2023) of surveillance data from Gabon measles surveillance program were collected and analyzed. Variables included age, sex, vaccination status and date, disease date, and anti-measles immunoglobulin M (IgM) status (determined by immunoassay). The rate of infection and association studies was done. Results showed that 60.6% (1,640/2,708) of suspected cases were unvaccinated against measles. Of suspected cases, 26.1% were laboratory-confirmed cases. Unvaccinated individuals were 5.9-7.7 times more likely to be anti-measles IgM positive (p < 0.0001). Children aged ≤5 years represented 70.8% of laboratory-confirmed cases; 15.5% (30/193) of childbearing age females were confirmed cases. In Gabon, nonimmunized and underimmunized individuals are driving up measles disease and constitute a challenge to measles elimination.