Molecular typing and epidemiology of non‐polio enteroviruses isolated from Yunnan Province, the People's Republic of China

This report presents an overview of human enteroviruses in Yunnan Province, the People's Republic of China. A total of 210 non-polioviruses isolated under acute flaccid paralysis (AFP) surveillance during a total study period of 5 years--1997 to 2000 and 2004--were examined. Of the 210 non-poliovirus isolates, 12 adenoviruses were serologically identified, and the remaining 198 isolates were used for molecular typing. The viral genomes of 195 non-polio enteroviruses (NPEVs) on VP1 partial region of virus capsid were translated to the corresponding amino acid sequences; these were compared with those of prototype strains. Based on molecular typing, 5 isolates were classified into 5 serotypes of the human enterovirus A species, 158 isolates, into 35 serotypes of the human enterovirus B species; and 32 isolates, into 6 serotypes of the human enterovirus C species. Viruses belonging to the human enterovirus D species were not isolated. Thus, under AFP surveillance, the human enterovirus B species accounted for 75.2% of the 210 isolates, and it was considered the predominant species. This was followed by human enterovirus C (12.2%), adenovirus (5.7%), and human enterovirus A (2.4%). Further, molecular analysis suggested that several serotypes of human enteroviruses B and C that exhibited genetic polymorphism were indigenous. Molecular typing methods may aid in understanding the epidemiology of NPEVs in Yunnan Province.