Seroprevalence in Niger from 2005 to 2019: estimates from the epidemiological surveillance of measles

Introduction: Congenital rubella syndrome is a pathology following maternal and then fetal infection with the rubella virus which can cause serious sequelae in children. The incidence of this syndrome has led a large number of countries to introduce rubella-containing vaccines into their immunization programs. Objective: In order to estimate the seroprevalence of this disease and assess the advisability of introducing the rubella vaccine, a descriptive cross-sectional study was carried out in Niger from 2005 to 2019. All regions of Niger were concerned by the study. Method: This was a documentary review-based on the epidemio-logical measles surveillance database (2005-2019). In this context, we have studied the serologically negative samples of suspected measles cases by performing an Elisa test for anti-rubella IgM. Results: Based on this data, the search for rubella was performed on 39.9% of the sample (5170/12938 suspected cases of measles). The prevalence of rubella was 7% (366/5170). The median age was 6 years with an interquartile range of 0 to 69 years. Rubella was common in all age groups with a predomi-nance among the 24-59 month (36.1%) and 5-9 year (33.6%) age groups the most affected. Of these cases, 52.8% were men, 47.2% were women with a sex ratio of 1.1. In two cases the sex was not determined. Rubella was found in all regions of Niger with a predominance in the regions of Maradi (28.8%), Tahoua (17%), and Zinder (15.5%). 53% of people with rubella were from rural areas, 47% from urban areas. During this study, the majority of cases were notified from January to April with a peak in April.