Bacterial pathogens and outcome determinants of childhood pyogenic meningitis in Ilorin, Nigeria

Abstract

Empirical antimicrobial therapy remainsjustifiable in childhood pyogenic meningitis (CPM), but the continuing efficacy in a particular setting requires periodic microbiological surveillance. It was this need that informed the present five-year retrospective study of consecutive admissions for CPM at the Emergency Paediatric Unit (EPU) of the University of Ilorin Teaching Hospital, Ilorin, Nigeria. Of the 71 cerebro-spinal fluid [CSF] analyses, 41 (57.6%) were Gram-smear positive (GSP). Gram-positive cocci (GPC) were identified in 23 (56.1%) smears, while 14 (34.2.%) had Gram-negative bacilli (GNB). Only three (7.3%) had Gram-negative diplococci (GND). Despite corroborative biochemical findings, the remaining 30 (42.3%), including two with tuberculous meningitis proved smear-negative. GPC cases had a mean age of 4.49 +/- 5.3yrs, GNB, 3.06 +/- 4.8yrs and GND, 4.47 +/- 4.9yrs. CSF isolates were made in 28 (39.4%) cases. Streptococcus pneumoniae accounted for a predominant 22 (78.6%) (P = 0.00), Haemophilus influenzae for 2 (7.1%), and Neisseria meningitidis for only 1 (3.5%) case. Whereas Strept. pneumoniae and H. influenzae isolates were uniformly sensitive to each of sultamicillin, cefuroxime, ceftriaxone and ceftazidime, 7.7% of Strept. pneumoniae were resistant to crystalline penicillin, 6.7% to ampicillin, and 69.2% to chloramphenicol; one of the two H. influenzae isolates was chloramphenicol-resistant. Amongst the 30 (42.3%) fatal cases, the length of stay was significantly shorter in GNB-positive cases (P = 0.045). Mortality was significantly higher amongst cases with purulent/turbid CSF at admission (P = 0.03), and in those with CSF protein of >150mg/dl (P = 0.02) and glucose <1mg/dl (P = 0.047). The present aetiological preponderance of GPC and Strept. pneumoniae in our study population, the high case-fatality, and the emerging resistance profile suggest the need for exploring additional control options including vaccination. We emphasize the need for periodic auditing of local antimicrobial policies in CPM.