Investigation of the dog-biting events and molecular evolution characteristics of rabies virus strains in Shuangbai county of Yunnan province / 中华实验和临床病毒学杂志

ABSTRACT

Objective@#To illustrate the epidemical characteristics of the dog-biting events and molecular evolution of rabies virus (RV) strains prevalent in Shuangbai county of Yunnan province, China.@*Methods@#Epidemical investigation on the dog-biting events and human cases were conducted and the brain tissues of the biting dogs and human cases were sampled post-mortem. Nucleoprotein (N) genes of the RVs were sequenced. Homology and phylogenetic analysis were performed using the relevant bioinformatics software.@*Results@#A total of 12 dog-biting events took place between 2011-2017 in Shuangbai county and 35 persons were bitten. Of the 12 events, 11 were investigated in time and 32 bitten persons received proper wound management and a full post-exposure vaccination course. Rabies has not developed in these wounded cases until now. However, due to failure to receive medical intervention and post-exposure treatment in time, 1 of 3 bitten persons in a single event died of rabies. RV N genes from 5 dogs and 1 person were sequenced. Phylogenetic tree showed that RV strains prevalent in Shuangbai county were closely related with the ones found in neighboring counties/cities such as Chuxiong, Lufeng, Jingdong and Xiangyun. All these strains were related to the ones denoted as clade China-I and prevalent in Sichuan province. Homology analysis showed 99.6%-100% homology in nucleotide and amino acid among the 6 RVs prevalent in Shuangbai county and those prevalent in Chuxiong, Lufeng, Xiangyun and clade China-I of Sichuan province. Compared with the China-I strains prevalent in Chuxiong, Zhaotong and Qujing prefectures between 2006-2007, the homology of nucleotide and amino acid were 97.1%-99.3% and 99.1%-99.6%, respectively.@*Conclusions@#Surveillance on the dog-biting events can prevent rabies in humans effectively. RV strains prevalent in Shuangbai county belong to clade China-I and have a close relationship with those of neighboring prefectures, cities, counties and the ones prevalent in Sichuan province.