ABSTRACT
Introduction
Bacterial meningitis remains a significant cause of morbidity and mortality in Nigeria, particularly within the northern meningitis belt. Robust laboratory surveillance is essential to detect outbreaks early, guide vaccination policies, and evaluate the effectiveness of response interventions. This analysis summarizes trends in national cerebrospinal meningitis (CSM) surveillance data from October 2024 to September 2025, highlighting patterns in age distribution, turnaround time (TAT), and EpiWeek-based reporting.
Methods
Data were analysed from 21 reporting states within the Nigeria Centre for Disease Control and Prevention (NCDC) cerebrospinal meningitis laboratory surveillance network. Variables included age, sex, pathogen, state, and epidemiological week (Epiweek). Laboratory confirmation was performed using real-time PCR for Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae. Turnaround time (TAT) was defined as the interval from specimen receipt to dispatch of results. Epiweeks were derived using the specimen receipt date as a proxy where collection dates were incomplete. Descriptive analyses were conducted to assess demographic patterns, temporal trends, pathogen distribution, and laboratory performance.
Results
The mean TAT was 2 days, and the median TAT was 1 day, indicating generally efficient laboratory response times. Confirmed cases had a median age of 10 years, with the highest positivity among children 5–14 years (47.3%) and young adults 15–24 years (25.5%), and a male predominance (61.2%). Neisseria meningitidis was the predominant pathogen (96.9%), with serogroups C (59.5%) and W (37.3%) most common, while Streptococcus pneumoniae and Haemophilus influenzae were rare. Cases clustered in northern meningitis belt states—Yobe, Sokoto, Kebbi, Gombe, and Jigawa—and peaked during the dry season (EpiWeeks 13–17), with the highest burden in the first quarter of 2025, followed by a decline.
Conclusion
The 2024–2025 data show Neisseria meningitidis (serogroups C and W) as the main cause of meningitis in northern Nigeria, mostly affecting children and young adults. Seasonal peaks were observed, and the short lab turnaround indicates improved efficiency. Data gaps and weaknesses in sample management highlight the need for strengthened surveillance and molecular capacity.