Current status of cerebrospinal meningitis and impact of the 2015 meningococcal C vaccination in Kebbi, Northwest Nigeria

Abstract

IntroductionFollowing the significant reduction of Neisseria meningitidis A (NmA) in most parts of northern Nigeria, a new strain of Neisseria meningitidis C (NmC) emerged in 2013 causing outbreaks in the north and recently spreading to southern parts of the Nigeria. This study provides detailed epidemiological investigation in the last four years. MethodsAnalysis of confirmed and suspected cases of meningitis in Kebbi, Nigeria from 2014 to June 2017 detected through Integrated Disease Surveillance and Response. ResultsOf the 2776 cases, 1568 were males, and 1208 females. The median age of males and females was 10 and 11 years (Interquartile range of ages is 9 years) respectively. The attack rate (AR) per 100,000 in the state between 2014 and 2017 was 13.2, 46.7, 2.2 and 3.2 respectively. Case fatality rate (CFR) in 2014 was highest in the 4 years analysed at 13.8%. Binary logistic regression analysis suggests that the odds of confirmation of meningitis was 3.6 (Odds ratio, OR 3.60, 95% CI 1.58–8.2; p = 0.002) times as high in the age group 6–10 years and 2.4 times in the age group 11–19 years compared to the age group 0–5 years (OR 2.44, 95% CI 1.09–5.48; p = 0.03). An epidemic of NmC in 2015, led to a reactive vaccination campaign in selected wards in Aliero and Jega targeting age groups 1–29 years old, with a coverage of 72% and 51% respectively. In 2016–2017 Aliero and Jega local government areas (LGA) had no recorded deaths due to meningitis, a significant improvement over 2015 mortality rates (MR) per 100,000 of 33.4 and 12.2 respectively. ConclusionThe CFR in the state is still very high, suggesting the need for a more coordinated approach aimed at improving disease notification and early treatment. Vaccination in Aliero and Jega LGAs have demonstrated the usefulness of meningococcal C vaccine in reduction of morbidity and mortality.