[The first imported measles case associated with genotype D4 measles virus in China]

This study reported the first imported measles case associated with genotype D4 measles virus in Shanxi province in China. The clinical specimen of throat swab was inoculated into Vero/SLAM culture to isolate the virus. A RT-PCR (Reverse transcription polymerase chain reaction, RT-PCR) was performed to amplify the 676 nucleotides sequence corresponding to the carboxyl terminus of measles virus nucleoprotein. The phylogenetic tree based on the 450 nucleotide acids of carboxyl terminus of N protein was constructed and the homology similarity was analyzed. The Shanxi isolate MVi/Shanxi. CHN/20. 09/1 was clustered within the same genotype group with WHO genotype D4 reference strain, Montreal. CAN/89, and the homology of nucleotide acid between Shanxi isolate and WHO genotype D4 reference strain was 97.3%. The homology of nucleotide acid and amino acid between Shanxi isolate and 2009 genotype D4 representative strain circulating in USA, Canada, India and Russian were 98.0%-100% and 97.3%-100%, respectively. These results showed that the virus isolated from the imported measles case was genotype D4. This is the first report that the genotype D4 measles virus was imported and isolated in China. It is important to accumulate baseline data of China and help to measure transmission pathways and to clarify epidemiological links.