The epidemiology of bacterial meningitis occurring in a Pacific Island population

Abstract

During a 36-month period 83 cases of bacterial meningitis were seen, giving an overall annual incidence rate of 134 per 10(5) population. The highest incidence was seen in infants (930 per 10(5) infants) and 59% of the patients were 0-5 years of age (incidence rate 207 per 10(5) children). Pathogens were successfully identified in 80% of the cases, by employing a combination of microscopy and antigen detection using a commercially available latex agglutination kit. Neisseria meningitidis was identified in 58%, Streptococcus pneumoniae in 29%, Haemophilus influenzae type b in 11% and dual infection with H. influenzae type b and S. pneumoniae in 3% of the cases. Serogrouping was successfully performed on cerebrospinal fluid (CSF) deposits from 8 cases of meningococcal meningitis; 7 belonged to serogroup C and 1 to serogroup Y. There was a significant difference in the geometric mean age of meningitis caused by the three organisms. There was no seasonal or geographical clustering of cases caused by N. meningitidis. Although admissions for severe pneumonia in children less than 5 years of age peaked during the cold dry season (July-October), this was not associated with a similar peak in meningitis admissions caused by H. influenzae or S. pneumoniae. The overall case fatality rate was 15.7%, and the highest case fatality rate was found in infants (28%). Meningitis caused by H. influenzae was associated with the highest case fatality rate (29%) and N. meningitidis with the lowest (8%), but the difference was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)