THE MOLECULAR EPIDEMIOLOGY OF TYPE-1 POLIOVIRUS IN CENTRAL-AFRICAN-REPUBLIC

An increase in the incidence of acute flaccid paralysis cases associat ed with wild-type 1 poliovirus occurred in children in the city of Ban gui, Central African Republic (CAR), in 1993 and 1994. Genetic relatio nships of 33 isolates were analysed by restriction fragment length pol ymorphism and by sequencing the VP1/2A junction region (150 nucleotide s) of the viral genome, Two distinct genotypes, A and B, were co-circu lating in 1993, while in 1994 only a third genotype, C, was observed. Comparison of the sequences found, with those of the sequences from is olates from neighbouring and other endemic countries revealed that gen otype A isolates were related to strains from Egypt (90.7% identity), genotype B isolates to strains from Kenya (96.7% identity), Sudan and Egypt, and genotype C isolates to strains from various countries in we stern and southern Africa (89.0% identity), Genotypic diversity and ge netic linkage with strains from neighbouring countries indicate intens e poliovirus circulation and transmission that does not respect nation al borders, Therefore, eradication of poliomyelitis from CAR can only be achieved by a coordinated multinational strategy that stops poliovi rus circulation in the whole of Africa.