Bacterial meningitis in Malawian adults: Pneumococcal disease is common, severe, and seasonal

We prospectively collected laboratory details and outcome data on ail patie nts with laboratory-confirmed cases of meningitis that presented Co our uni t in Blantyre, Malawi, from 1 April 1998 through 31 March 1999, There were 502 patients with cases of meningitis; the most common causative organisms were Cryptococcus neoformans and Streptococcus pneumoniae. This pattern pro bably reflects the local human immunodeficiency virus (HIV) seroprevalence (31%) and is different from the pattern in 1974, when Neisseria meningitidi s was the most common isolate, There has been an 8-fold increase in the num ber of meningitis cases per year since 1974, and a doubling of the percenta ge of medical admissions due to meningitis. The inpatient mortality rate am ong patients with cases of pneumococcal meningitis was 61%, and in the grou p as a whole was 41%. Despite the HIV-related pattern of infecting pathogen s among these cases of meningitis and the increased incidence of the condit ion, there was evidence that the typical seasonal pattern of pneumococcal m eningitis, which peaks in the cold, dry season, was preserved.