宁波市动物染蜱情况调查结果分析

目的:初步了解宁波市动物染蜱现状,为进一步建立蜱媒传染病综合监测系统。方法:采用现状调查方法,摸清宁波市家养和野外动物染蜱情况。结果:家养动物蜱感染率为29.94%,以狗染蜱最高;野外动物染蜱阳性率为6.67%;动物染蜱部位以肩背、耳廓和颈部等前半身最常见。结论:宁波市动物染蜱情况不容乐观,应引起公共卫生部门的重视。     

2011-2012年平顶山市蜱类种群密度初步调查

目的了解平顶山地区蜱类种群密度情况,为制定该地区蜱的防治措施提供借鉴与科学依据。方法游离蜱调查采用人工布旗法、寄生蜱调查采用动物体表检视法。结果平顶山地区蜱类种群是长角血蜱,宝丰县游离蜱和寄生蜱平均密度分别为5.93只/人工小时,10.19只/头;舞钢市游离蜱和寄生蜱平均密度分别为3.97只/人工小时,10只/头;鲁山县游离蜱和寄生蜱平均密度分别为1.89只/人工小时,2.83只/头。湛河区游离蜱和寄生蜱平均密度分别为1.3只/人工小时,1.22只/头。结论平顶山地区密度不高,建议家畜圈养,并定期灭治。     

通化地区莱姆病调查分析

目的:了解该地区人群和动物莱姆病感染率,以及传播媒介蜱-全沟硬蜱的地理分布及其病原菌携带情况。方法:应用BSK、直接免疫荧光抗体法(DFA)法,培养检测病原体和酶联免疫吸附试验(ELISA)进行人群、动物IgG抗体检测。结果:蜱平均带菌率为35.09%、人群平均感染率为6.67%、5种动物平均感染率为22.12%。结论:通化地区、长白山脉存在莱姆病疫源地,人群、动物感染率较高。     

浙江省建德市蜱媒传染病综合监测研究

目的 了解建德地区蜱媒传染病主要宿主和媒介的种群密度、季节消长、染带关系和病原体携带状况,为蜱媒传染病预防控制提供科学依据。方法 采用布旗法、宿主动物体表检蜱法采集蜱,用鼠笼捕捉鼠形动物,采用PCR方法检测其蜱媒传染病感染情况。结果 建德地区主要蜱种有长角血蜱、中华硬蜱和镰形扇头蜱,长角血蜱为优势种,布旗法6月蜱密度最高,体表检蜱法6月带蜱率最高。在蜱及宿主动物中检出嗜吞噬细胞无形体、巴贝西原虫、查菲埃立克体、立克次体、巴尔通体、肾综合征出血热病毒6种蜱媒传染病病原体,并存在病原体复合感染。结论 建德地区蜱媒传染病的宿主和媒介广泛分布,而且携带多种病原体,需要采取措施进行防制。     

阿拉山口口岸地区蜱类区系调查及宿主动物染带关系监测分析

目的查清口岸地区蜱类本底种群构成、分布特点及与宿主的寄生关系,监测蜱类跨界动态信息,为识别外来物种、传疫情况提供基础科学依据。方法 2008年1-12月主要在口岸地区鼠疫监测点范围内,用人工诱捕法、布旗法,在家畜、家禽、野生动物、小型哺乳动物、洞穴中采集蜱类,将优势种群进行病原体监测。结果经一年的调查,采集蜱类1科5属8种1780只,其中包括进口牛皮中采集的334只蜱。优势种为亚洲璃眼蜱,占78.8%。该蜱除城区外在各监测点均有分布,也是寄生在家畜、小型哺乳动物体表的重要种类。常见种有银盾革蜱、残缘璃眼蜱、盾糙璃眼蜱、短垫血蜱,前3种是寄生在牛、羊、马、骆驼等体表的常见种,后1种是寄生在虎鼬、大耳猬等野生小型动物的常见种。稀有种有雷氏硬蜱、血红扇头蜱,常寄生在狼体表、鼠洞等。罕见种为短小扇头蜱。在进口牛皮中采集蜱类334只。结论经过一年的调查,初步查清了口岸地区蜱类媒介本底的种群构成、分布数量、季节消长及与宿主的染带关系,进口牛皮染蜱的动态信息,为防治疫病疫情、蜱类媒介的传入传出打下了基础。     

驻山东省部队野外驻训地域蜱种群调查分析

目的摸清山东省野外部队驻训地域蜱分布和种群密度。方法驻训地域游离蜱采用人工小时布旗法;动物宿主寄生蜱采用动物体表捡蜱法。结果4个驻训地域均有蜱活动,蜱活动高峰期共捕获蜱虫12808只,经鉴定均为长角血蜱。不同驻训地域的蜱密度存在显著差异性(F=6.791,P<0.05),以淄博市沂源县(199.73只/h)最高,其次为青岛市西海岸新区(141.33只/h)和泰安市岱岳区(32.67只/h),济南历城区(17.60只/h)最低。相同驻训地域不同年份的蜱密度无明显差异性(F=0.583,P>0.05)。济南市历城区和泰安市岱岳区4月开始出现蜱,之后蜱密度迅速上升,5月达到最高峰。淄博市沂源县以羊染蜱率和染蜱指数(94.83%、96.9)最高,牛(77.78%、44.4)次之,犬类(63.16%、4.1)最低。未药浴羊群染蜱率为100.00%,染蜱指数为177.5;定期药浴羊群染蜱率为91.43%,染蜱指数为39.0。结论蜱在山东省部队驻训地域广泛分布,密度高峰期来临前的4月是孳生地防蜱的最佳时间,对蜱侵害度较高的山羊采取药浴防蜱效果明显。     

药物驱蜱对新疆出血热流行抑制作用的现场实验研究

目的探讨药物驱蜱对新疆出血热（XHF）在家畜中流行的抑制效果。方法采用药物驱蜱方式对塔里木盆地疫区内的羊群进行对比实验研究。结果实验组羔羊在服用驱蜱药物阿维菌素后,羔羊体外寄生蜱的染蜱率为55.0%,蜱指数为1.0,而未服用阿维菌素的对照组感染率为100%,蜱指数为11.2,实验组羔羊体外寄生蜱的感染率和蜱指数分别较对照组低45%和10.2;实验6个月后,实验组克里米亚-刚果出血热病毒（CCHFV）抗体阳性率为22.4%,显著低于对照组（45.9%）,与实验组在实验前的CCHFV抗体阳性率（23.7%）基本一致。结论 XHF流行地区羔羊服用驱蜱药物阿维菌素可阻碍蜱类对羔羊的侵袭,抑制XHF在羔羊中的流行。     

天津市主要蜱类及其病原携带调查

目的了解天津市蜱类及其病原携带情况。方法采用人工小时布旗法和犬类体表检视法对全市16个区县199块社区绿地和204只犬类开展蜱类调查;同时7个区县送检社区绿地、家畜和犬类及病人等处采集的蜱。用PCR法分别检测布尼亚病毒、嗜粒细胞无形体、伯氏疏螺旋体和巴尔通体。结果蜱的收集和构成：2011年3-8月在全市8个区县共采集蜱197只,全沟硬蜱58只,占29.4%;长角血蜱139只,占70.6%。蜱密度：人工小时布旗法对全市16个区县199块社区绿地进行调查,蜱密度1.01%。染蜱率：采用犬类体表检视法调查全市16个区县的204只犬类,染蜱率1.47%,总蜱指数0.02。蜱病原携带检测：布尼亚病毒核酸Realtime RT-PCR检测阴性;嗜粒细胞无形体核酸巢氏PCR检测阴性;伯氏疏螺旋体核酸巢式PCR检测阴性;巴尔通体核酸PCR检测阴性。结论全沟硬蜱和长角血蜱是天津市的优势蜱种。今后蜱类防治重点要加强环境治理,清除杂草;同时城市中宠物狗携带蜱尤其需引起重视。有必要对蜱等生物媒介宿主动物及其病原体进行更深入的生态与分子流行病学研究。     

黑龙江口岸蜱类斑点热群立克次体感染状况初探

〔目的〕对黑龙江口岸蜱类感染斑点热群立克次体的状况进行调查,为口岸病媒防制工作提供科学依据。〔方法〕对黑龙江10个口岸蜱类进行采集,并通过病原培养分离,动物试验后进行分子生物学检测。〔结果〕在黑龙江口岸采集的蜱类样本中检出斑点热群立克次体,以全沟硬蜱的感染率最高。〔结论〕中俄边境口岸蜱类携带病原体具有复杂性。本次研究为控制中俄边境口岸发生蜱传斑点热疫情提供了预防控制依据。     

鼠与蜱感染人致病性巴贝虫状况的初步研究

目的了解绥芬河口岸鼠、蜱感染人致病性巴贝虫情况。方法捕鼠选用中号钢板鼠夹,布于农田、林缘,晚放晨收;采集鼠体寄生蜱,用人工小时布旗法于林缘、苔草地采集游离蜱;采用PCR检测所获鼠、蜱人致病性巴贝虫DNA片段。结果捕获鼠50只,采集寄生蜱8只,游离蜱1 501只。绥芬河口岸鼠形动物巴贝虫感染率为32%,其中黑线姬鼠的感染率(11/33)与东方田鼠(4/12)均为33.33%;鼠形动物体表寄生蜱均为全沟硬蜱,其巴贝虫感染率为25%(2/8);游离蜱4种,为森林革蜱、全沟硬蜱、嗜群血蜱、日本血蜱,巴贝虫感染率为7.87%。结论绥芬河口岸存在人巴贝虫自然疫源地,该检测结果为下一步深入了解该病的性质及其流行病学特征提供了基础。     

长葛市2004—2009年法定报告传染病疫情分析

目的了解自2004年传染病实行网络直报以来长葛市法定传染病发病趋势和流行特征,为制定和完善防制策略提供科学依据。方法采用描述性流行病学方法对2004—2009年葛市法定传染病疫情资料进行分析。结果 2004—2009年长葛市法定传染病年均发病率为254.5122/10万,死亡率为1.3658/10万,病死率为0.5366%。6年来,发病趋势起伏不定：2004—2005年呈上升趋势,2005—2007年呈下降状态,2007—2009年呈上升趋势;死亡率、病死率均呈上升趋势。近几年,血源及性传播传染病位于法定传染病发病首位,且发病呈上升趋势。目前,威胁长葛市人民群众健康的传染病主要是乙型肝炎、肺结核、丙型肝炎、淋病、梅毒、艾滋病、手足口病等。结论长葛市传染病防治工作任务艰巨,加强血源及性传播传染和新发传染病的监测和防制是长葛市疾病控制工作的重中之重。     

Phenotypic evaluation of genetic resistance to the tick Rhipicephalus (Boophilus) microplus in Argentine Creole cattle

The objective of this work was to characterize the Argentine Creole cattle breed through the identification of individual phenotypic variations in the levels of infestation with Rhipicephalus (Boophilus) microplus. We evaluated 179 heifers exposed to successive artificial infestations from 2015 to 2018, achieving a total of 663 observations. Tick counts were assessed with the linear mixed model, considering year of evaluation, time of infestation, dam's age and nutritional status during the evaluated period as fixed effects. The average tick count value obtained allowed to classify the breed as highly resistant to the tick charge (99.3%). Although the previous nutritional condition of the animals did not affect the individual charge response, weight gain during the trial showed a significantly negative correlation. We conclude that the Argentine Creole breed is an attractive genetic alternative for cattle breeding in endemic regions, either as a pure breed or a cross-breed.     

蜱虫危害及其媒介效能

蜱虫是一种能传播多种病原体的节肢动物,蜱虫叮咬人类或动物后,会将其体内的病原体传播给宿主,是一种仅次于蚊虫的重要病媒生物。媒介效能是评价蜱虫潜在传播疾病的重要指标,本文就蜱虫对人畜的危害,蜱虫面临的新挑战,蜱虫媒介效能及其影响因素研究现状作了基本综述。     

Rotational and selective protocols using acaricides to control a multi-resistant strain of Rhipicephalus microplus under field conditions in Southern Brazil

The cattle tick, Rhipicephalus microplus, causes severe economic losses to beef and dairy production in several countries. The control of the cattle tick is based mostly on chemical acaricides. Currently, there are reports of tick populations resistant to all six classes of acaricides available on the market. The aim of this work was to evaluate two protocols for the control of the cattle tick, R. microplus, under field conditions. For that, an acaricide rotational-based approach and selective (partial)-based protocols were tested against a multi-resistant tick strain. Eighteen Brangus cattle were divided into three experimental groups: Group 1, a rotational-based approach aiming at six treatments per year (spring–spring period) using four different classes of acaricide (IPV6 protocol); Group 2, a selective (partial) and rotational-based protocol, in which only half of the animals with the highest tick counts were treated (IPV7S protocol); and Group 3 (non-treated). The protocols were able to maintain low tick infestation during the 57 weeks of study. The two experimental groups showed lower tick counts than the non-treated group, but not between them. Weekly efficacy of the experimental protocols reached 95% in Group 1 and 88% in Group 2. Herein, we proposed two protocols of cattle tick control (IPV6 and IPV7S) for use in multi-resistant tick populations in Southern Brazil.     

Effect of vaccination with a recombinant Bm86 antigen preparation on natural infestations of Boophilus microplus in grazing dairy and beef pure and cross-bred cattle in Brazil

Current methods for the control of the cattle tick Boophilus microplus infestations are not effective and the parasite remains a serious problem for the cattle industry in tropical and sub-tropical areas. Recent advances have introduced the possibility for the immunological control of the parasite through the use of recombinant vaccines. Recently, it was shown that the recombinant vaccine Gavac™ (Heber Biotec S.A.) is able to control B. microplus populations in artificially infected grazing dairy cattle in Cuba. To assay the effect of the vaccine on a different B. microplus strain and under different ecological conditions, we conducted a trial in Brazil on grazing dairy and beef pure and cross-bred cattle under natural infestation conditions. A farm in the northeast of the state of Sao Paulo was selected and two groups of animals per breed were included in the experiment and were maintained grazing on separate but similar pastures. For each breed, one group was vaccinated with the vaccine Gavac and the second group was not vaccinated and was employed as a control. In vaccinated cattle, during 36 weeks of experiment, the average infestation rate was maintained below 78 ticks per animal while average infestation peaks (mean ± S.E.) of 144 ± 44 ticks per animal (for dairy cross-bred cattle) and 195 ± 42 ticks per animal (for beef cross-bred cattle) were recorded in the control groups. Tick infestation rates showed statistical significant differences (p=0.04) between both experimental groups throughout the experiment. These results clearly showed, as in the Cuban study, that the vaccine controlled tick numbers in successive generations in the field.     

Oral vaccination with vaccinia virus expressing the tick antigen subolesin inhibits tick feeding and transmission of Borrelia burgdorferi

Immunization with the Ixodes scapularis protein, subolesin, has previously been shown to protect hosts against tick infestation and to decrease acquisition of Anaplsma marginale and Babesia bigemina. Here we report the efficacy of subolesin, a conserved tick protein that can act as a regulator of gene expression, expressed from vaccinia virus for use as an orally delivered reservoir - targeted vaccine for prevention of tick infestation and acquisition/transmission of Borrelia burgdorferi to its tick and mouse hosts. We cloned subolesin into vaccinia virus and showed that it is expressed from mammalian cells infected with the recombinant virus in vitro. We then vaccinated mice by oral gavage. A single dose of the vaccine was sufficient for mice to generate antibody response to subolesin. Vaccination with the subolesin expressing vaccinia virus inhibited tick infestation by 52% compared to control vaccination with vaccinia virus and reduced uptake of B. burgdorferi among the surviving ticks that fed to repletion by 34%. There was a reduction in transmission of B. burgdorferi to uninfected vaccinated mice of 40% compared to controls. These results suggest that subolesin has potential as a component of a reservoir targeted vaccine to decrease B. burgdorferi, Babesia and Anaplasma species infections in their natural hosts.     

Tick infestation on roe deer in relation to geographic and remotely sensed climatic variables in a tick-borne encephalitis endemic area

Roe deer Capreolus capreolus are among the most important feeding hosts for the sheep tick Ixodes ricinus, thus contributing to the occurrence of tick-borne diseases in Europe. Tick-borne encephalitis (TBE), which is transmitted by co-feeding of larvae and nymphs on rodents, requires precise climatic conditions to occur. We used roe deer as sentinels for potential circulation of TBE virus in Northern Italy, by examining the association between tick infestation, occurrence of TBE human cases, geographical and climatic parameters. Tick infestation on roe deer, and particularly frequency of co-feeding, was clearly associated with the geographic location and the autumnal cooling rate. Consistently, TBE occurrence in humans was geographically related to co-feeding tick abundance. The surveillance of tick infestation on roe deer, combined with remotely sensed climatic data, could therefore be used as an inexpensive early risk assessment tool of favourable conditions for TBE emergence and persistence in humans.