Bacteriology and sensitivity patterns of acute adult bacterial meningitis: a seven-year overview

ABSTRACT

Bacterial meningitis is a potentially fatal infection and its rapid diagnosis has an important role in the prognosis of the disease. The objective of this study was to determine the microscopic, bacteriologic and clinical characteristics of adult bacterial meningitis in Chaharmahal province of Iran over a period of seven years. Materials and Thirty-one patients with bacterial meningitis in Shahrekord Kashani Hospital were observed in a period of seven years [Oct. 1993 - Sept. 2000]. The clinical findings, type of bacteria isolated from cerebrospinal fluid [CSF] samples, CSF leucocyte counts, CSF cultures and the antibiotic sensitivity profile of the common bacterial isolates were evaluated. The annual incidence of the disease was about 0.64 per 100,000 inhabitants. Neck stiffness and impairment of consciousness were seen only in a half of Behnam Zamanzad, Hedayatollah Shirzadeh, Mohammad Reza Naficy Department of Microbiology and Immunology, Shahrekord University of Medical Sciences, Shahrekord, Iran the cases. In 50% of patients, the CSF leucocyte counts were 1000-10,000/mm3, while in 26% of the cases the count was below 500/mm3. Eighty-three% of CSF cultures were reported positive. Steptococcus pneumoniae [58%], Neisseria meningitidis [19%] and Gram negative enteric bacilli [6%] were the most common isolates. Gram's stain of sedimented CSF helped in the presumptive identification of the causative bacteria in 80% of the cases. Fifty% of the pneumococcal isolates were resistant to penicillin and 13% were resistant to chloramphenicol. Conclusions: A combination of CSF culture and microscopic examination is highly specific for early diagnosis of bacterial meningitis, and performing an antibacterial sensitivity test is recommended before any antibiotic therapy