Epidemics of serogroup A Neisseria meningitidis of subgroup III in Africa, 1989-94.

A total of 125 strains of Neisseria meningitidis recovered in the course of outbreaks from patients with systemic disease in 11 African countries between 1989 and 1994 were analysed by serogrouping, serotyping and multilocus enzyme electrophoresis. Of the 125 patient strains 115 (92%) belonged to the clone-complex of serogroup A meningococci, designated subgroup III. Among the remaining strains, 4 were also serogroup A, but belonged to the clonal groups I and IV-1 (2 strains each), whilst 6 strains (4 serogroup C and 2 serogroup W135) represented clones of the ET-37 complex. Our results indicated that the second pandemic caused by clones of subgroup III is still spreading in Africa. Towards the West it has reached Niger, Mali, Guinea and The Gambia, and towards the South, the Central African Republic, Uganda, Rwanda, Burundi, Tanzania and Zambia.