Treatment and outcome of pneumococcal meningitis in adults. Study of a recent series of 70 episodes

BACKGROUND: Pneumococcal meningitis (PM) is an infection with high morbidity and mortality. The aim of this study was to evaluate the most relevant clinical, epidemiologic and evolutive characteristics of a recent series of adult patients with this disease. METHODS: Over a period of 10 years all the patients with PM diagnosed by isolation of this microorganism in the cerebrospinal fluid (CSF) were evaluated from a clinical, therapeutic and evolutive points of view. The impact of the new therapies in the disease and the variables associated with mortality were analyzed. RESULTS: Seventy episodes of PM were diagnosed, 60% being found in patients over the age of 50 years. The male/female relationship was 2/1. Fifty-three percent of the patients had other underlying diseases. Acute otitis media (AOM) was the source in 34% of the cases, in 11% the patients had a fistula of CSF and in 9% a pneumonia. At the time of diagnosis 74% of the patients had some degree of reduction in the level of consciousness and in 40% of the episodes the presence of neurologic local manifestations were observed. A decrease in sensitivity to penicillin was observed in 33% of the microorganisms isolated. Third generation cephalosporins were used as initial treatment in 57 episodes and penicillin in other 11 episodes. Adjuvant treatment with dexamethasone, mannitol and/or diphenylhydantoin was administered in 54% of the patients. Overall mortality was 23%: the factors associated with an unfavourable evolution were the existence of underlying disease, deep alteration in the level of consciousness at the time of diagnosis, the coexistence of pneumonia and the absence of adjuvant therapy. CONCLUSIONS: Mortality in pneumococcal meningitis is high. The most relevant risk factor is the initial degree of consciousness. Adjuvant therapies probably determine a reduction in the rate of mortality.