Surveillance of pneumococcal meningitis among children in Sindh, Southern Pakistan

Background. Information about the burden of invasive pneumococcal disease among children in Pakistan is limited. Methods. Surveillance of bacterial meningitis among children aged <5 years was set up at 18 hospitals in southern Pakistan that fulfilled the following criteria: (1) >30 pediatric admissions weekly, (2) skilled personnel to perform lumbar punctures, and (3) close proximity to an Aga Khan University Hospital laboratory collection point. Results. A total of 2690 children were admitted to the hospital with suspected acute bacterial meningitis, and 2646 (98%) underwent lumbar puncture. Of the 2646 cerebrospinal fluid specimens obtained, 412 (16%) were purulent, and pathogens were detected by culture or latex agglutination testing in 83 (20.1%) of the purulent specimens. Of the 83 isolates detected, 48 (57.8%) were Haemophilus influenzae type b, 32 (38.5%) were Streptococcus pneumoniae, and 3 (3.6%) were Neisseria meningiditis. Overall, 81% of the pathogens detected were from children aged <1 year. More than 50% of families reported definite prior antimicrobial use. The minimum detected incidence rates of purulent meningitis in Hyderabad were 112 cases per 100,000 children aged <1 year and 45.3 cases per 100,000 children aged <5 years. After adjustment for limitations in access to care and the low sensitivity of cerebrospinal fluid culture, the adjusted incidence rates of pneumococcal meningitis were 81 cases per 100,000 children aged <1 year (95% confidence interval, 26.2-190.5 cases per 100,000) and 20 cases per 100,000 children aged <5 years (95% confidence interval, 7.3-43.7 cases per 100,000). Of the 32 children with pneumococcal meningitis, 8 (25%) died during hospitalization. Conclusions. Our surveillance system detected a substantial burden of purulent meningitis among infants and children in southern Pakistan. H. influenzae type b and S. pneumoniae accounted for >90% of detected pathogens. The use of vaccines against these 2 pathogens could prevent a substantial portion of disease and deaths in Pakistan.