Genetic characterization of measles viruses in China, 2004

Abstract

Genetic characterization of wild-type measles virus was studied using nucleotide sequencing of the C-terminal region of the N protein gene and phylogenetic analysis on 59 isolates from 16 provinces of China in 2004. The results showed that all of the isolates belonged to genotype H1. 51 isolates were belonged to cluster 1 and 8 isolates were cluster 2 and Viruses from both clusters were distributed throughout China without distinct geographic pattern. The nucleotide sequence and predicted amino acid homologies of the 59 H1 strains were 96.5%-100% and 95.7%-100%, respectively. The report showed that the transmission pattern of genotype H1 viruses in China in 2004 was consistent with ongoing endemic transmission of multiple lineages of a single, endemic genotype. Multiple transmission pathways leaded to multiple lineages within endemic genotype.

Figure 1

The geographic distribution of Chinese measles isolates in 2004. No isolates were received from provinces in white.

Figure 2

phylogenetic tree of the N gene sequences of 59 wild-type measles isolates from China compared to the WHO reference sequences for each genotype. The WHO reference strains and china vaccine, Shanghai-191 were shown in black. Cluster 1 was shown in red, while cluster 2 was shown in blue. WHO strain name is indicated for each sequence.