Genetic characteristics of Coxsackievirus A 16 VP1 in Hainan province of China in 2010

Objective To analyzed the molecular epidemic characteristics of Coxsackievirus A 16 (CA16) which had caused the spread of hand-foot-and-mouth disease (HFMD) in Hainan province during 2010.Methods Totally 56 CA16 strains were isolated from patients with HFMD in Hainan Province during 2010.Reverse transcription polymerase chain reaction (RT-PCR) was used to amplify and sequence the VP1 coding region.These sequences were used together with those of CA16 representative strains to construct the phylogenetic tree.Results And those of 34 strains belonged to genetic subtype B1a of B1 genetic subtype,22 strains belonged to genetic subtype B1b.The B1a genetic subtypes strains were mainly isolated in Haikou City and other four adjacent counties located in the northwest of Hainan Province,and the B1b genetic subtypes strains were mainly isolated in Haikou City and other four adjacent counties located in the middle,southwest of Hainan Province.Conclusion Genetic subtype B1 a and B 1b were prevalentand co-occurring in Hainan during 2010.The distribution of CA16 strains had a certain of geographical characteristics.The results suggested there were at least two large chains of CA16 transmission in Hainan.In 2008-2010,the percentage of CA16 infection in Hainan province from HFMD cases was 8.05％,5.35％,35.45％respectively,which indicates it has increased obviously. Key words: Coxsackievirus infection ;  Hand-foot-and-mouth disease ;  Genotype