Outbreak of serotype W135 Neisseria meningitidis in central river region of the Gambia between February and June 2012: a hospital-based review of paediatric cases.

Background: Meningitis still accounts for many deaths in children especially during epidemics in countries within the African meningitis belt. Between February and May 2012, the Gambia witnessed an outbreak of meningitis in two of its six regions. This study presents a clinical perspective of this outbreak in central river region of the Gambia. It evaluated the outbreak pattern, clinical features, and mortality among suspected cases that presented to the hospital during the outbreak.

Methodology: This is a prospective observational study of suspected cases of meningitis that presented to the pediatric ward of the Bansang Hospital during the outbreak period. Confirmed cases of meningitis were consecutively enrolled, and those with negative blood cultures presenting during the same period were employed as controls.

Result: Two hundred and four suspected cases of meningitis presented to the pediatric ward during the outbreak. Ninety were confirmed as meningitis cases. The W135 strain of Neisseria meningitidis was responsible for 89 (98.9%) of meningitis cases seen with an incidence rate of 74.9/100,000 in children (0-14 years) and in-hospital case fatality rate of 7.9%. Highest attack rate was among the 12-49 months age group. Clinical features such as meningeal signs (neck stiffness), conjunctivitis, and joint swelling were seen more in cases than controls. Contact history with relatives, who had fever in previous 2 weeks prior to illness was significantly seen more in cases. Adjusted regression analysis showed 7.5 more likelihood of infection with positive contact history (odds ratio [OR]: 7.2 confidence interval [CI]: [3.39-15.73]). There was no significant difference in death outcome between cases and controls (OR: 0.78 CI: [0.29-2.13]). The double peak wave-like pattern of the epidemic curve noted during this outbreak suggests a disseminated outbreak originating from an index case with propagated spread.

Conclusion: There is need for more effective surveillance and incorporation of vaccine against meningitis into the expanded program on immunization schedule of the Gambia and other countries within the meningitic epidemic belt.