[Molecular epidemiological study of measles viruses isolated in Qinghai Province during 2000-2011].

Objective To understand the genetic characteristics of wild measles virus in Hubei province during 2008-2012. Methods To collect throat swab specimens from measles outbreak or sporadic cases in Hubei province during 2008-2012, and perform viral isolation using Vero/SLAM cell, then genotype identification and phylogenetic analysis were performed. Results 26 measles virus strains were isolated from clinical specimens collected in the 9 cities in Hubei province from 2008-2012, they all belong to H1a subgenotype within the wild type measles viruses of H1 genotype, no imported genotypes were found. The nucleotide and amino acid identities among 26 measles virus strains of H1a subgenotype were for 97.1%-100% and 95.3%-100%, respectively. And compared with the Chinese vaccine strain (Shanghai191 strain), the nucleotide and amino acid identity were 91.8%-92.5% and 87.4%-90.0%, respectively. Genetic phylogenetic analysis showed that all 26 measles virus strains belong to two different evolutionary branches, represent two transmission chains, and close to the measles virus isolated in other provinces in genetic phylogeny and endemic time. Conclusion H1a subgenotype of measles virus continues to spread in Hubei province from 2008-2012, the measles viruses in Hubei province co-evolved with the viruses in other provinces in China. This study provides an important scientific basis for measles elimination in Hubei province. Key words: Measles virus; Genotype; Epidemiology, molecular