Descriptive characterization of measles in Kebbi State, Nigeria, 2013-2017

Introduction: Measles is a highly infectious, viral disease, and endemic in developing countries. In Nigeria, and other countries in sub-Saharan Africa (SSA), the peak of transmission is from October to March. The disease is still common and very often, fatal in developing countries. This analysis was conducted to describe the characteristics of suspected measles cases in Kebbi State between 2013 and 2017, describe the outcome status and case fatality rates, and identify factors associated with outcome status. Methods: We obtained data from the Epidemiology Unit of the Kebbi State Ministry of Health, Nigeria. Kebbi State has a tropical continental type of climate, characterised by a distinct wet and dry season. We cleaned and coded data. We conducted a descriptive analysis of measles surveillance data between 2013 and 2017 to describe the epidemiology of measles in Kebbi State in time, place, and person. We also conducted a bivariate analysis to determine the association between the outcome status of cases and some other variables. Results: A total of 9,819 suspected cases were line-listed between January 2013 to December 2017. Overall, 7,087 (72%) were below the age of five years and 5,008 (51%) were males. The median age was 2 years (range was 1 month to 49 years). The incidence rate was 831 per 100,000 (for age group 1-4 years), and 29.8 per 100,000 (for 15 years and above). Most of the suspected cases (88%, 8641) were reported during the first half of each year during the period under review. Birnin Kebbi, the state capital, reported the highest number of cases – 1855 (18%). Nine thousand and eighty-one (92%) cases were unvaccinated. There were 121 deaths (case fatality rate: 1.2), most of whom were below the age of 5 years. However, Sakaba local government area had the highest CFR of 8% (29/347). The age group 5-9 years had the highest CFR of 3.0% (1756/9819). The highest CFR (5%, 28/555) was recorded in 2014. Several reported cases were non-case-based. Age of onset of the disease and vaccination status were found to be statistically significantly associated with outcome (OR: 3.6, 95% CI: 2.50-5.19), and OR: 3.4, 95% CI 2.1-5.2) for the age of onset and doses of measles received respectively. Conclusion: There was the persistence of measles over the review period affecting primarily children below five years. This may be due to vaccinations being missed by children despite activities to strengthen coverage. Enhanced routine immunization, through community sensitization and mobilization activities, was recommended to the State Ministry of Health.