Molecular epidemiology of mumps virus strains circulating in south-west China from 2007 to 2009.

The genetic characteristics of mumps virus (MuV) strains isolated from sporadic mumps cases between 2007 and 2009 in three provinces of south-west China were investigated. MuV detection was carried out by nested RT-PCR on 117 cases. The small hydrophobic gene of 33 isolated strains was identified, and sequence analysis revealed that all the isolates belonged to the lineage genotype F with slight nucleotide variation. Furthermore, the virus haemagglutinin-neuraminidase and nucleoprotein antigens exhibited a high degree of nucleotide and amino acid similarity (>99 %) within all isolates, whilst the fusion protein appeared to have certain geographical differences. This study on molecular surveillance will help to monitor the circulation of MuV in China.