Phylogenetic analysis of the nucleoprotein gene of measles viruses prevalent in Nantong, Jiangsu Province, China, during 2010

Measles control in China is monitored in part by surveillance of circulating wild-type viruses. The objective of this study was genetic characterization and phylogenetic analysis of measles strains in the Nantong City region of Jiangsu province, China, during 2010. Sera from suspected cases were tested for IgM antibodies and measles virus isolated by inoculation of transport medium onto Vero/SLAM cells. Isolated strains were phylogenetically analysed according to the nucleotide sequence of the C-terminal region of the nucleoprotein gene amplified by RT-PCR. The results revealed 34 cases confirmed by positive IgM, for an incidence of 0·45/100 000. Six isolates identified were all clustered within genotype H1. The findings reported here support continued endemic transmission of measles virus in China.