摘要
目的:调查陕西省是否存在土拉弗朗西斯菌病的自然疫源地。方法:蜱类调查采用布旗法;小型啮齿动物调查采用夜夹法,病例采用回顾性流行病学调查;血清学检测采用酶联免疫吸附实验;病原分子生物学检测采用巢式-PCR法;统计学处理应用SPSS 9.0统计学软件。结果:调查发现富县、陇县和南郑县硬蜱科(ixodidae)5属15种蜱类,即硬蜱属(ixodes)1种、革蜱属(dermacentor)5种、血蜱属(haemaphysalis)4种、璃眼蜱属(hyalomma)3种和扇头蜱属(rhipicephalus)2种,以革蜱和血蜱种类较多。啮齿目7科16属24种,即松鼠科(sciuridae)2属2种,鼯鼠科(pteromyidae)2属2种,跳鼠科(dipididae)1属1种,鼹形鼠科(spalacidae)1属2种,仓鼠科(cricetidae)4属5种,鼠科(muridae)5属11种,豪猪科(hystricidae)1属1种,以鼠科种类最多。检测富县、陇县和南郑县部分林区居民血清样本707份,其中土拉弗朗西斯菌病血清IgG抗体阳性49份,总阳性率为6.93%,说明当地人群中存在土拉弗朗西斯菌病的自然感染。检测蜱标本1 117只,从达吉斯坦革蜱(D.daghestanicus)、日本血蜱(H.japonica)、嗜群血蜱(H.concinna)等3个蜱种中检测出25只蜱为土拉弗朗西斯菌标本阳性,总阳性率为2.24%。其中以日本血蜱的阳性率最高,为15.39%(χ2=20.91,P=0.01),说明当地蜱体中存在土拉弗朗西斯菌的自然感染。当地分布的达乌尔黄鼠(S.dauricus)、花鼠(T.sibiricus)、黑线姬鼠(A.agrarius)、小家鼠(M.musculus)和褐家鼠(R.norvegicus)等小型兽类,在周边省区已被学者证实为土拉弗朗西斯菌病的保菌宿主和传播者,提示富县、陇县和南郑县部分林区存在土拉弗朗西斯菌的保菌宿主啮齿目小型兽类。从25份阳性标本中选取10份进行序列测序,获得核酸序列与土拉弗朗西斯菌B亚种菌株序列AF247690.2 100%同源;对阳性标本进行SSTR9区域扩增,共有6种不同的拷贝数,其中拷贝数为9的居多(40.00%);利用MEGA 4.0软件进行聚类分析显示20份标本主要分为两大群。结论:陕西省富县、陇县和南郑县部分林区存在土拉弗朗西斯菌病的自然疫源地。
Objective：To investigate whether there is natural epidemic focus of Francisella tularensis in Shaanxi province.Methods：Tick samples were collected by molecular method.Small rodents were investigated by night trap and retrospective epidemiological investigation.The colloidal gold test strips were used for serological tests.The nested-PCR method was used for pathogenic molecular biology test.SPSS 9.0 software was used for analysis.Results：Fifteen species of ixodidae and 24 species of rodentia were collected in Fu County,Long County and Nanzheng County,especially the large number of Dermacentor,Haemaphysalis and Muridae.The 707 serum samples were collected from the residents of Fu County,Long County and Nanzheng County.The serum IgG antibody was detected in 49 samples,the total positive rate was 6.93%,indicating that the local population had different degrees of the natural infection of Francisella tularensis.A total of 1 117 ticks were detected from some of the three counties,and25 ticks were detected from the three species：D.daghestanicus,H.Japonica and H.concinna,the total positive rate was 2.24%.Among them,the positive rate of H.Japonica was the highest,reaching 15.39%（χ2=20.91,P =0.01）,indicating that the natural infection in ticks was existed.The local distribution of the small rodents such as S.dauricus,T.sibiricus,A.agrarius,M.musculus and R.norvegicus distributes in surrounding provinces had been confirmed as the bacteria host and disseminator by previous research,indicating that the small rodents also existed the natural infection.Ten cases were sequenced from 25 positive specimens,obtained nucleotide sequence and Francisella tularensis of B substrains sequence homologous to AF247690.2 100%.The copy No.9 of 6 different copies was predominantly（40.00%）in the SSTR9 region.The clustering analysis using MEGA 4.0 software showed that there were two major groups.Conclusion：The natural epidemic focus of Francisella tularensis is existed in Fu County,Long County and Nanzheng County of Shaanxi province.
作者
郑龙
ZHENG Long(The Third Hospital of PLA,Baoji 721004,China)
出处
《西北国防医学杂志》
CAS
2018年第7期426-431,共6页
Medical Journal of National Defending Forces in Northwest China
基金
军队后勤科研计划项目课题(CLZ12J007)
