Pathogenic isolates in meningitis patients in Dar Es Salaam, Tanzania.

OBJECTIVES

To determine, from laboratory records, the spectrum of bacterial and fungal pathogens isolated from cerebrospinal fluids (CSF) of in-patients with meningitis at Muhimbili Medical Centre (MMC) in Dar es Salaam and to ascertain the laboratory results (based on microscopy and culture) using the latex agglutination technique.

DESIGN

A retrospective study based on laboratory records of CSF samples investigated between November 1999 and June 2000 and a cross-sectional study involving investigation of 60 freshly collected CSF samples by conventional (microscopy and culture) and antigen detection by latex agglutination technique (LAT).

SETTING

Muhimbili Medical Centre in Dar es Salaam, Tanzania.

INVESTIGATIONS: Information from laboratory records, bacteriological examination of CSF by microscopy, culture and agglutination techniques.

RESULTS

According to records, a total of 1144 CSF samples were investigated between November 1999 and June 2000, of which two hundred and twenty two specimens (19.4%) had a positive bacterial or fungal culture. Fifty five of the isolates were from children (aged less than 15 years) and were; 20 (36.4%) were Streptococcus pneumoniae, 12(21.8%) were Cryptococcus neoformans, and nine (16.4%) were Haemophilus influenzae type b. The remaining 14 (25%) isolates included three group B streptococci, three Klebsiella spp, two E. coli, two Staphylococcus aureus, two Pseudomonas spp, one Moraxella and one Salmonella group B. For adults a total of 167 positive cultures were reported and 163 (97.6%) of the isolates were Cryptococcus neoformans, two (1.2%) were Pseudomonas spp. and two were S. aureus. There was good agreement between conventional microscopy and culture with the latex agglutination technique in the identification of CSF pathogens.

CONCLUSION

In children, S. pneumonia, and bacteria in general constituted the majority of isolates. Adult cases of meningitis were almost exclusively due to C. neoformans. Overall, C. neoformans appears to be the most common isolate among meningitis cases. Based on LAT results, our routine diagnostic methods seem to be adequate in the identification of the common CSF pathogens.