新疆维吾尔自治区动物莱姆病的流行病学调查

Epidemiological investigation of Lyme disease in animals in Xinjiang Uygur Autonomous Region,China

目的对新疆维吾尔自治区(简称新疆)4个地区5种蜱虫宿主动物进行莱姆病流行病学调查,并分析伯氏疏螺旋体(Borrelia burgdorferi)的流行基因型。方法取于新疆乌鲁木齐、伊犁、昌吉及喀什4个地区采集的牛、绵羊、山羊、马和犬血清样本共814份,采用ELISA法测定血清中莱姆病IgG抗体。于上述地区收集蜱虫135只,提取DNA,以其为模板,经巢式PCR法扩增伯氏疏螺旋体5S-23S rRNA间隔区片段,取阳性样本进行测序。测序结果与GenBank中已登录的伯氏疏螺旋体5S-23S rRNA基因间隔区序列进行BLAST比对,并应用MEGA X软件构建系统进化树。结果新疆乌鲁木齐、喀什、伊犁、昌吉地区血清样本莱姆病IgG抗体阳性率分别为23.6%、2.4%、2.7%和0,4个地区差异有统计学意义(χ^(2)=48.481,P<0.001);牛、绵羊、山羊、犬和马血清样本的莱姆病IgG抗体阳性率分别为1.1%、4.4%、18.7%、60.5%和0,5种动物差异有统计学意义(χ^(2)=129.03,P<0.001)。135份蜱虫DNA样本中有24份为伯氏疏螺旋体阳性,带菌率约17.78%,包括B.garinii(占比75%)、B.afzelii(占比16.67%)、B.burgdorferi(占比8.33%)3种基因型。结论新疆乌鲁木齐、喀什、伊犁3个地区的牛、绵羊、山羊和犬4种动物存在莱姆病感染,以B.garinii为主要流行基因型。本研究为新疆地区莱姆病的防控提供了参考。

Objective To investigate the epidemiology of Lyme disease and analyze the genotypes of Borrelia burgdorferi in five kinds of host animals of ticks in four cities of Xinjiang Uygur Autonomous Region,China.MethodsA total of 814 serum samples were collected from cattle,sheep,goats,horses and dogs in Urumqi,Ili,Changji and Kashgar Cities,and determined for IgG antibody against Lyme disease.A total of 135 ticks in the above-mentioned cities were collected,from which DNAs were extracted and used as template for amplification of the 5S-23S rRNA spacer fragments of B.burgdorferi by nested PCR.The positive samples were sequenced,and the results were compared with those of 5S-23S rRNA spacer of B.burgdorferi reported in GenBank by BLAST,and a phylogenetic tree was constructed by MEGA X software.ResultsThe IgG antibody positive rates against Lyme disease in Urumqi,Ili,Changji and Kashgar Cities were 23.6%,2.4%,2.7%and 0 respectively,which showed significant difference(χ^(2)=48.481,P<0.001).However,the positive rates in cattle,sheep,goats,dogs and horses were 1.1%,4.4%,18.7%,60.5%and 0 respectively,which showed sig-nificant difference(χ^(2)=129.03,P<0.001).Of the 135 tick DNA samples,24 were positive for B.burgdorferi,indicating a carrier rate of 17.78%.Phylogenetic analysis showed that the genotypes B.garinii accounted for 75%,while B.afzelii accounted for 16.67%,and B.burgdorferi accounted for 8.33%.ConclusionThere are Lyme diseases in cattle,sheep,goats and dogs in Urumqi,Kashgar and Ili Cities of Xinjiang Uygur Autonomous Region,China,of which the major genotype is B.garinii.The study provides a scientific basis for prevention and control of Lyme disease in Xinjiang.