Molecular epidemiology of rabies in Guangxi Province, south of China.

BACKGROUND

Surveillance data for rabies in Guangxi Province in China showed that human rabies cases have gradually increased since 1996.

OBJECTIVE

To evaluate the epidemiology of rabies at the molecular level and provide suggestions for effective prevention of rabies in Guangxi.

STUDY

DESIGN

Since 2000, 1569 brains from suspected rabid animals were collected from different areas of Guangxi. Rabies virus was isolated from 42 samples. RT-PCR was used to amplify a 455 nucleotide segment of the 3'-terminal of the N gene. The sequencing data from that segment was used for phylogenetic analysis.

RESULTS

Nucleotide homology comparisons and phylogenetic tree analysis based on this sequence indicated that all the rabies virus isolates from Guangxi belonged to genotype 1 and could be divided into four groups. Groups I, II and IV included 23, 10 and 8 isolates, respectively. These had nucleotide homologies of 97.1-100%, 98.2-100% and 99.1-99.6%, respectively. Only the GXN119 strain belonged to group III. Group I had two group-specific mutations: T90N and E110D. Group II had one group-specific mutation of T42S.

CONCLUSIONS

This study showed that rabies virus isolates from Guangxi have a close genetic relationship and topographical distribution.