Eleven-year study of causes of neonatal bacterial meningitis in Ahvaz, Iran

Abstract

Background: Bacterial meningitis is a devastating infection with a high mortality rate, especially in neonates. The aim of this study was to determine the causative agents that cause bacterial meningitis in Khuzestan province in the south-western region of Iran.

Methods: A descriptive, cross-sectional study was carried out from 1997 to 2007 at the neonatal ward of a university teaching hospital (Emam Khomeini hospital) in Ahvaz. All infants younger than 29 days old who suffered from meningitis were included. Laboratory tests included Gram stain, culture, and biochemical tests. Cases were defined as meningitis if the cerebrospinal fluid culture was positive.

Results: Based on cerebrospinal fluid culture, 31 infants were identified as having bacterial meningitis. Eleven (35.5%) of these cases were caused by Klebsiella pneumoniae, nine (29%) were caused by Enterobacter spp., three (9.6%) were caused by Escherichia coli, three (9.6%) were caused by Enterococcus spp., two (6.4%) were caused by Acinetobacter, and one case each (3.2%) was caused by Staphylococcus aureus, Pseudomonas aeruginosa and nontypeable Haemophilus influenzae. The male-to-female ratio was 2 : 1 (67.7% were male). The birthweights of 20 (64.5%) patients were under 2500 g and 11 (35.4%) patients had normal birthweights. Thirteen (42%) were early-onset cases and 18 (58%) were late-onset cases. More than half of the cases (54.8%) acquired the infection from the hospital. Blood cultures were positive for 18 (58%) patients. Thirty-two percent of cases died in spite of treatment.

Conclusions: Klebsiella pneumoniae and Enterobacter spp. were the two main causative agents that caused neonatal bacterial meningitis, and nosocomial meningitis was the most common type in our ward.