Bacterial and fungal meningitis and antimicrobial susceptibility pattern in Tikur Anbessa University Hospital, Addis Ababa, Ethiopia.

BACKGROUND: Meningitis is usually caused by viral, bacterial or fungal pathogens. Bacterial meningitis is a medical emergency and if untreated has a high mortality rate. Even among those who survive the infection, some may develop permanent neurological disorders.

OBJECTIVES: This study was undertaken to isolate and identify the bacterial and fungal etiologic agents of meningitis and to access the susceptibility pattern of bacterial isolates.

METHODS: During the period of November 2007 to June 2008, 340 cerebrospinal fluid (CSF) specimens were obtained from suspected cases of meningitis admitted to Tikur Anbessa University Hospital, Addis Ababa, Ethiopia. Microbiological analysis was performed on CSF specimens using standard procedures.

RESULTS: Of the 340 patients investigated, 53.5% were males and 46.5% were females. Over half of the patients (51.2%) were children (1 month to 16 years) and the remaining 32.6% and 16.2% were neonates (below 1 month of age) and adults (above 16 yrs of age), respectively. Fever was the commonest clinical feature observed in all age groups. Of the 340 CSF specimens, 26 (7.6%) had a positive bacterial or fungal culture. Bacterial isolates accounted for 84.6% of the total isolates. Among the bacteria, Streptococcus pneumoniae accounted for 36.4% followed by Haemophilus influenzae type b (Hib) and Nessieria meningitidis (serogroup A and C) (13.6%) each. Cryptococcus neoformans was the only fungal isolate. All gram positive bacteria were sensitive to ceftriaxone, ciprofloxacin, chloramphenicol, erythromycin and rifampicin and showed low level of resistance (< 60%) to penicillin, tetracycline and trimethoprim-sulphamethoxazole. The gram-negative bacteria showed high level of resistance (> 80%) to tetracycline and trimethoprim-sulphamethoxazole, intermediate level of resistance (60-80%) to ampicilin and low level of resistance (< 60%) to ceftriaxone, ciprofloxacin, gentamicin, chloramphenicol and rifampicin. Multiple resistance (resistance to two or more drugs) was observed in 18.2% and 100% gram positive and gram-negative bacteria, respectively.

CONCLUSION: This study showed that the predominant pathogens of meningitis were S. pneumoniae, H. influenzae and N. meningitidis. Ceftriaxone and ciprofloxacin were the most effective drugs against these organisms. Continuous periodic surveillance is required to form a comprehensive and updated understanding of the etiologies and antimicrobial resistance pattern for appropriate management of meningitis cases in the country.