Objective: One-year prospective observational study of meningitis diagnosed at a third level hospital.
Patients and methods: All patients with a cerebrospinal fluid (CSF) specimen with cyto-biochemical characteristics and clinical picture consistent with meningitis were included in the study. They were followed from admission to hospital up to discharge or exitus. The epidemiologic characteristics of patients, etiology, related risk factors and predisposing situations, CSF characteristics, clinical manifestations, clinical course, and antibiotic susceptibility of the causative agents were analyzed.
Results: Ninety-five cases were included. Seventy-six (69.4%) were community acquired and 29 (30.5%) nosocomially acquired meningitis. Among community acquired meningitis, 31 (46.9%) were of bacterial origin (8 N. meningitidis, 3 H. influenzae, 2 S. pneumoniae, 1 Streptococcus group B, 1 Listeria monocytogenes, 1 Staphylococcus aureus, and 1 Brucella spp.); CSF culture was negative in 14 cases (41.2%). In most cases neither risk factor nor predisposing situations were detected. Patients with purulent meningitis and negative CSF culture had a significantly lower number of complications than patients with positive CSF culture. Among patients previously treated with beta-lactam antibiotics (8 cases) the probability of a negative CSF culture was greater than among not treated patients (OR 16.00, 95% CI 1.45-764.68; p = 0.011). The remaining cyto-biochemical characteristics were similar in both groups. Thirty-five cases (53.03%) of community acquisition were lymphocytic meningitis (31 viral, 3 tuberculous, and 1 luetic meningitis). Among nosocomial cases (29 cases, 30.5%), most were caused by gram-negative bacilli and microorganisms of the Staphylococcus genus. Fourteen cases (48.2%) were related to some type of neurosurgical procedure. Overall, only two exitus cases were recorded.
Conclusions: The etiologic agents of community acquired meningitis are mainly N. meningitidis, S. pneumoniae and Haemophilus influenzae. The previous antibiotic therapy did not influence thy cyto-biochemical characteristics of CSF but it did influence the yielding of culture. Meningitis with negative CSF culture has a significantly lower number of complications. The availability of a Neurosurgery Department at a hospital confers a change in the epidemiologic spectrum of diagnosed meningitis, with a higher incidence of nosocomial meningitis. In our environment, a substantial proportion of cases due to Staphylococcus microorganisms was observed.