莱州市蜱种分类及感染新布尼亚病毒的病原学研究

Study on the Classification of Ticks and Etiology of Novel Bunyavirus in Ticks,Laizhou City

目的了解莱州市蜱的种类以及蜱携带发热伴血小板减少综合征新布尼亚病毒的感染状况,为证实当地发热伴血小板减少综合征的传播媒介提供科学依据。方法在莱州市有发热伴血小板减少综合征病例发生的自然村,收集动物体表的寄生蜱和采用布旗法收集野外的游离蜱,开展蜱的分类鉴定,并采用实时荧光定量PCR进行新布尼亚病毒的病原学检测。结果 2011年在莱州市共采集到2 593只蜱。按蜱的种类分类,莱州地区共采集到长角血蜱2 573只和血红扇头蜱6只,最低感染率分别为4.20%和16.67%;采集到铃头血蜱9只和中华革蜱5只,未检测到新布尼亚病毒核酸阳性。按照蜱的不同发育时期分类,共采集到成蜱1 449只、若蜱995只、幼蜱149只,成蜱、若蜱和幼蜱的最低感染率分别为4.07%、4.52%和2.68%;实验室培养期间收获22份卵,其中2份卵新布尼亚病毒核酸检测阳性,最低感染率为9.09%;按照动物来源分类,共采集羊蜱1 435只、狗蜱74只、牛蜱128只、鸡蜱61只、刺猬蜱24只,除鸡蜱、刺猬蜱未检测到新布尼亚病毒核酸外,羊蜱、狗蜱和牛蜱中SFTSV最低感染率分别为5.37%、12.16%和1.56%;野外采集蜱871只,最低感染率为2.18%。结论不同发育时期的蜱均有不同程度的新布尼亚病毒感染;长角血蜱、血红扇头蜱可能为新布尼亚病毒的传播媒介,且新布尼亚病毒具有垂直传播的可能。

Objective To understand investigate the tick species and SFTSV（Severe Fever with Thrombocytopenia Syndrome Bunyavirus）infection rates in ticks in Laizhou city,so as to provide the scientific basis for confirming tick transmission of SFTSV. Methods Ticks were collected from domestic animals and vegetation by ＂ the woolen flannel cloth dragging method＂ in the villages where SFTS cases had been reported in Laizhou city.The ticks were identified by morphology and then were detected for SFTSV by real-time PCR. Results A total of 2 593 ticks were collected in Laizhou city in 2011,of which 2 573 were Haemaphysalis longicornis and 6 H.campanulata.The minimum infection rate（MIR）of SFTSV RNA in ticks was 4.20% and 16.67%in H.longicornis and H.campanulata,respectively.9 H.campanulata and 6 D.sinicus were collected and they were all negative to SFTSV RNA.According to different stages of ticks,ticks were classified to 1 449 adults,995nymphs,149 larvae,and the SFTSV MIR of ticks was 4.07%,4.52% and 2.68%,respectively.22 eggs were incubated at laboratory.Two of them were SFTSV RNA positive,and the MIRwas 9.09%.According to different domestic animals of tick parasites,1435 from sheep,128 from cattle,74 from dogs,61 from chicken and 24 from hedgehog were collected.Except for ticks from chicken and hedgehog being negative to SFTSV,the SFTSV MIR of ticks from sheep,cattle and dogs was 5.40%,1.60%and 12.20%,respectively.871 ticks were collected from vegetation,and the SFTSV MIR was 2.20%. Conclusion Ticks from all the four stages are detected SFTS RNA positive.Haemaphysalis longicornis and H.campanulata may be the main vectors of SFTSV,and vertical transmission of SFTSV in ticks is possible.