MOLECULAR CHARACTERIZATION OF TYPE-1 POLIOVIRUSES ASSOCIATED WITH EPIDEMICS IN SOUTH-AFRICA

The molecular epidemiology of wild-type 1 polioviruses isolated in Sou th Africa during 2 major poliomyelitis epidemics in the 1980s and duri ng the pre- and inter-epidemic periods was investigated by partial seq uence analysis across the VP1/2A junction. Poliovirus-specific primers were used to amplify and subsequently sequence the region of interest . Viruses belonging to different genotypes were found to have been res ponsible for the 2 outbreaks. The Gazankulu outbreak in 1982 was cause d by a poliovirus genotype which was unique to South Africa and which circulated endemically throughout much of the country between 1980 and 1985. Two additional genotypes, imported from the Middle East and Wes t Africa, cocirculated endemically with the South African genotype bet ween 1982 and 1985. The 1988 epidemic in Kwazulu-Natal was attributed to an imported genotype apparently introduced into South Africa in 198 5 from countries north of the border. This genotype displaced the 3 ge notypes previously in circulation a nd continued to be transmitted wit h in the country until 1989, when the last confirmed cases of poliomye litis associated with wild-type viruses were documented. All circulati ng wild-type poliovirus strains appear to have been eliminated from So uth Africa. (C) 1997 Wiley-Liss, Inc.