Meningococcal infections in the Province of Québec, Canada, during the period 1991 to 1992.

A total of 234 strains of Neisseria meningitidis obtained from hospitalized patients living in the province of Québec during the period 1991 to 1992 were characterized according to their serogroup, serotype, subtype, electrophoretic type, and antimicrobial susceptibility. All these strains were recovered from sterile body fluids, except for one strain that was isolated postmortem from a cutaneous lesion. For both years, serogroup C was the most prevalent (69.7%), followed by serogroup B (27.4%). Serotype 2a represented 80.3% of serogroup C isolates, and P1.2 was the most common subtype associated with this serotype. Clone ET 15 accounted for 76.5% of serogroup C isolates and 90.0% of serotype 2a strains. Although meningococcal disease occurred mostly in children under the age of 5 (9.7 cases per 100,000 children), with a peak incidence for children under 1 (20.3 cases per 100,000 children), most fatalities occurred among teenagers (12 to 19 years old). The total fatality rate was 11.5%, and serogroup C strains were responsible for 88.9% of these fatalities. Thirteen strains had a reduced susceptibility to penicillin G, and 28 strains were resistant to sulfadiazine. One strain was resistant to both rifampin and sulfadiazine and showed a reduced susceptibility to penicillin G.