Characteristics of Cerebrospinal Meningitis Cases in 2017 Outbreak, Sokoto State, Nigeria: A Secondary Data Analysis

Introduction: Cerebro-Spinal Meningitis (CSM) is an acute illness affecting surrounding layers of the brain and spinal cord, mostly caused by bacterial infection. The disease is responsible for the occurrence of epidemic meningitis in the African Meningitic belt. For many years, this region has experienced a large serogroup A epidemic every 7-10 years. A sharp decrease in the number of reported cases was demonstrated in countries where Men Afrivac has been introduced. However, serogroup replacement with serotype C was noted in the region, which has posed a serious threat to eliminating CSM epidemics. We describe the characteristics of cerebrospinal meningitis cases in the 2017 outbreak in Sokoto state, Nigeria.

Methodology: We obtained CSM data from the state epidemiology unit from 7th February to 24th May 2017. We extracted data on demographic characteristics, clinical features, case management and outcome of cases. We used Microsoft Excel and SPSS to analyze the data for proportions, cross-tabulations and chi-square test to find associations between variables.

Results: A total of 4969 CSM cases were recorded, with 283 deaths (case fatality rate: 5.7%). The cumulative attack rate was 96.4/ 100,000 populations. The highest proportion of cases was among ≥ the 15-year age group 2063(41.5%), and males were more affected, 2843(57.2%). Of the total 4969 suspected CSM cases, specimens were collected for only 225 (4.4%) cases, of which 58 (25.8%) were positive. Most 48 (82.8%) of the positive specimen were of NmC serotype. Only age was found to predict outcome (aOR: 1.52; 95% CI= 1.18 – 1.97).

Conclusion: Sokoto State outbreak of Cerebro-spinal meningitis in 2017 was huge and largely caused by NmC. Those aged less than 15 years might be at higher risk of dying from CSM and we therefore recommend that specific preventive interventions such as vaccination and awareness creation should target this age group.