湖南省湘潭市2004-2010年狂犬病流行病学研究

Epidemiological Study of Rabies in Xiangtan,Hunan from 2004 to 2010

目的分析湘潭市狂犬病流行病学特征并探讨狂犬病毒N基因的遗传进化关系,为狂犬病的防控提供科学依据。方法收集2004-2010年湘潭市狂犬病病例资料进行描述性流行病学分析,用巢式RT-PCR法从家犬脑组织标本内获得N基因并进行测序,并构建系统发生树进行遗传特征分析。结果 2004-2010年共报告91例人间狂犬病例,97.80%被犬所伤,平均潜伏期为44.18 d。共采集412份犬脑组织标本,经巢式RT-PCR确证6份标本核酸阳性,感染率为1.46%。测定3株狂犬病毒株的N基因序列,均为基因Ⅰ型,毒株间的核苷酸同源性为97.2%~98.1%,构建系统发生树属于同一组群,其中与湖南省内邵阳、湘西州、外省如贵州、江苏、河南、浙江省等分离的毒株表现出较近的亲缘关系,且与疫苗株CTN株有较近的亲缘关系。结论湘潭市仍然是狂犬病高发区,引起的病毒不是新型病毒,应做好综合防控措施遏制狂犬病疫情的发生。

Objective To analyze the epidemiological characteristics of rabies in Xiangtan Prefecture,to explore phylogenetic relation of the rabies virus N gene in the genetic evolution,and to provide a scientific basis for prevention and control of rabies. Methods Based on the data of rabies cases in Xiangtan Prefecture from 2004 to 2010,a descriptive epidemiological study was conducted.Nested RT-PCR method was used to detect N genes from the brain samples of domestic dogs,and then N genes were sequenced.Phylogenetic tree was constructed and the genetic characteristics were analyzed. Results Totally 91 cases of human rabies were reported during the period of 2004～2010,97.80% of which were injured by dogs,experiencing an average incubation period of 44.18 days.412 dog-brain-tissue samples were collected,and 6 samples were confirmed positive ones by nested RT-PCR,with an infection rate of 1.46%.The sequences of 3 strains of rabies N gene were determined,and all of them were genotypeⅠ,with a nucleotide homology of 97.2%～98.1%.The phylogenetic tree showed that the three strains of Xiangtan rabies virus belonged to the same group cluster,where the three Xiangtan strains enjoyed closer genetic relationships with strains from Shaoyang and Xiangxi Autonomus Prefecture within the province,other provinces such as Guizhou,Jiangsu,Henan,Zhejiang as well as vaccine strains CTN. Conclusions The incidence of rabies was prevalent in Xiangtan Prefecture though the virus was gene type-1.Comprehensive prevention and control measures should be enhanced to curb the incidence of rabies.