[New method of molecular typing in human Enteroviruses: characterization of Madagascar "untypable" strains].

Enteroviruses, members of the family Picornaviridae, are responsible for a wide variety of diseases and represent a major public health hazard. Typing of non polio enterovirus (NPEV) infection is traditionally based on a serum neutralization assay. However, this method is time-consuming, labor-intensive, expensive, and may fail to identify antigenic variation. A new molecular typing involving partial sequencing of the genome has been recently developed. In this study, 46 NPEV strains were analyzed, including 37 antigenicaly "untypeable" viruses. Partial sequencing of the C-end of the viral capsid protein VP1 and pairwise identity with the prototype strains allow us to assign a serotype for all "untypeable" viruses. The results show a large number and wide variety of Coxsackieviruses A which belong to the HEV-C species and also Echoviruses and Coxsackieviruses B of the HEV-B species. This method may be useful to identify all NPEV serotypes in Madagascar and to assess the possible impact of circulating NPEV populations, as we enter the final stage of poliomyelitis eradication.