青海省达日县棘球蚴病流行病学调查

Epidemiological Survey on Echinococcosis in Darlag County of Qinghai Province

目的分析青海省果洛藏族自治州达日县棘球蚴病的流行分布现状,为制定预防控制措施提供科学依据。方法于2007年8～9月对达日县6个乡各2～3个自然村的3周岁以上常驻牧民分别用B超、间接红细胞凝集试验(IHA)和间接ELISA法(重组AgB和Em18抗原)检查两型棘球蚴病患病和感染情况。并调查当地啮齿类动物、牦牛、绵羊和野犬的感染情况,对采集的棘球绦虫和棘球蚴用PCR-RFLP方法进行虫种鉴定,并确定其基因型。收集牧民的家犬粪便,用双抗体夹心法检测粪抗原阳性率。结果共调查牧民1723人,B超查出棘球蚴病患者236例(占13.7%),其中囊型和泡型棘球蚴病患病率分别为5.5%(95/1723)和8.2%(141/1723)。男、女性棘球蚴病患病率分别为11.6%和16.0%(χ2=7.0,P<0.05)。家犬粪抗原阳性率为11.3%(31/275)。剖检9只无主犬,其中5只棘球绦虫感染阳性,对检获的虫体经PCR-RFLP鉴定,1只犬感染细粒棘球绦虫,基因型为G1,4只犬感染多房棘球绦虫。牦牛、绵羊的细粒棘球蚴感染率分别为26.4%(14/53)和5/16,对从牦牛、绵羊检获的细粒棘球蚴经PCR-RFLP鉴定,基因型均为G1。捕获高原鼠兔239只,石渠棘球绦虫感染率为11.3%(27/239)。结论达日县存在细粒棘球绦虫、多房棘球绦虫和石渠棘球绦虫的分布,泡型和囊型棘球蚴病在人群中严重流行,犬是细粒棘球绦虫和多房棘球绦虫主要传染源。

Objective To make an epidemiological investigation on eehinococcosis in Darlag County, Guoluo Tibetan Autonomous Prefecture of Qinghai Province. Methods Local participants were screened for echinococeosis using B ultrasound from August to September in 2007. IHA was carried out to detect antibody in human sera. Indirect ELISA using reeombinant-AgB and Em18 antigen was conducted to further diagnose the human alveolar eehinocoeeosis （AE） and cystic eehinococcosis （CE） . The prevalence of eehinococcosis in wild rodents, yaks, sheep and dogs was examined either by dissection or through slaughterhouses. Adult worms and hydatid cysts were detected by PCR-RFLP to discriminate 3 Echinococcus species and genotype of Eg. Dog feces were tested by double antibody sandwich ELISA method to confirm the eoproantigen positive rate. Results 1 723 people were examined by ultrasound and 236 were clinically diagnosed as hydatid diseases with an overall morbidity of 13.7%, of which 5.5% were CE and 8.2% were AE. Prevalence in males and females was 11.6% and 15.6% respectively with a statistically significant difference （χ^2=7.0, P〈 0.05） . Prevalence in herdsmen and monks/nuns was as high as 23.0% and 13.2%, respectively. Adult worms were found in 5 out of 9 stray dogs by necropsy. 27 of 239 pikas （Ochotona curzoniae） were infected by E. shiquicus （11.3%）. CE prevalence in sheep and yaks was 26.4% and 5/16 respectively. The Eg genotype was G1 （sheep strain）. Conclusion Three species of Echinococcus, e.g.E, granulosus, E. multilocularis and E. shiquicus are all prevalent in Darlag County. The prevalence of both AE and CE in human population is high in the area. Domestic dogs are the primary definitive host for both E. granulosus and E. multilocularis.