A PREDICTABLE COMEBACK - THE SECOND PANDEMIC OF INFECTIONS CAUSED BY NEISSERIA-MENINGITIDIS SEROGROUP-A SUBGROUP-III IN AFRICA, 1995

Between 14 January and 4 April 1995 we isolated and characterized 44 m eningococcal strains in Cameroon, Chad, Niger, and Burkina Faso; among these was the strain A:4:P1.9/clone III-1, which was involved in the second meningitis pandemic. This isolate was found in the clonal form in Niger and strains of the ET-37 complex were also found in the other three study countries, but apparently did not cause epidemics. One st rain (Y:2a:P1.2,5 (ET-37 complex)) was isolated in January 1995 and an other (A:4:P1.9) in March 1995 in Garoua (Cameroon). Eight strains wer e isolated in Moundou (Chad) between January and April 1995: the A:LF: P1.9/clone III-1 (1 strain); members of the ET-37 complex (Y:2a:P1.2,5 (4 strains), Y:NT:P1.2,5 (I strain), and Y:2a:-(I strain)); and serog roup X (1 strain). In Niger, 31 strains were isolated between February and April 1995 from different regions. All were A:4:P1.9/clone III-1; between November 1994 and April 1995 there were 23814 cases of mening itis reported of which 2227 resulted in death. Three strains were isol ated in Burkina Faso in April 1995: two were Y:2a:P1.2,5 (ET-37 comple x) and one was A:4:P1.9/clone III-1. Thus in 1995 the epidemic and inv asive strain (A:4:P1.9/clone III-1) responsible for the second pandemi c was present in the four countries (Cameroon, Chad, Niger and Burkino Faso) that make up the area frequently affected by such epidemics and where cases are generally reported during the dry season.