Tick zoonoses in the southern part of Switzerland (Canton Ticino): occurrence of Borrelia burgdorferi sensu lato and Rickettsia sp.

The diversity and the distribution of tick species and their infection rates by the pathogenic micro-organism Borrelia burgdorferi sensu lato, the etiologic agent of Lyme borreliosis, and Rickettsia sp., were studied in Canton Ticino (the southern part of Switzerland). Ticks specimens collected from animals and humans were classified and analysed for the presence of both pathogens. In particular, PCR analysis was performed for the detection of Borrelia spirochetes in Ixodes ricinus and Ixodes hexagonus, and the hemolymph test was done on Rhipicephalus sanguineus for the detection of Rickettsia sp. PCR assays, performed on 424 of the 989 collected ticks, revealed a low rate of infection (around 2%) of both vectors I. ricinus and I. hexagonus by B. burgdorferi sensu lato. These results are in agreement with the modest number of Lyme borreliosis cases yearly recorded in Ticino. Further, through analysis of DNA sequences, the strains carried by the infected ticks were identified as belonging to the genomic group VS116. The widespread finding of the Mediterranean species Rhipicephalus sanguineus in different locations from July 1994 to October 1995 demonstrates its establishment in Ticino. Of the 210 specimens collected, 70 were analysed and one was infected by Rickettsia sp.     

New Rickettsiae in ticks collected in territories of the former soviet union

Dermacentor nuttallii from Siberia, Rhipicephalus sanguineus from Crimea, and Rh. pumilio from the Astrakhan region were infected with Rickettsia sibirica (12%), R. conorii (8%), and the Astrakhan fever agent (3%), respectively. Three new Rickettsiae of the R. massiliae genogroup were identified in ticks by 16S rDNA, gltA, and ompA sequencing.     

Detection of antibodies to tick salivary antigens among patients from a region of Spain

With a view to determine which tick species bite humans most frequently in the province of Soria (Spain) and to know whether these species act as vectors of Rickettsia conorii and/or Borrelia burgdorferi, we analysed the presence of antibodies against salivary proteins of several tick species and of antibodies against R. conorii and B. burgdorferi sensu lato in 102 samples of serum. The sera were collected from 63 patients who were treated for tick bites at the health services of the Soria Health Area. Thirty-nine percent of the patients displayed antibodies against Dermacentor marginatus; 21% against Ixodes ricinus, and 6% against Rhipicephalus sanguineus. IgM antibodies against R. conorii were found in 15 patients, but none of the patients included in the study displayed IgG/IgM Abs against B. burgdorferi sensu lato. In 30% of the patients bitten by I. ricinus and in 24% bitten by D. marginatus, antibodies against R. conorii were found. None of the patients who had been bitten by R. sanguineus expressed antibodies against this pathogen. The results obtained here suggest that D. marginatus and I. ricinus are the main vectors of the spotted fever group rickettsiae in our environment and that the role of R. sanguineus in the transmission of these rickettsiae is debatable.     

Epidemiology of boutonneuse fever in western Sicily. Distribution and prevalence of spotted fever group rickettsial infection in dog ticks (Rhipicephalus sanguineus)

The distribution and prevalence of spotted fever group rickettsial infection in the ixodid dog tick Rhipicephalus sanguineus were found to occur at a rate of 19.7% with variation related to geographic and sociooccupational factors. A higher rate of infection was demonstrated in ticks removed from dogs associated with documented cases of boutonneuse fever. The results fit into available clinical and seroepidemiologic data on Rickettsia conorii infection in western Sicily.     

Tick species and tick-borne infections identified in population from a rural area of Spain

To determine the tick species that bite humans in the province of Soria (Spain) and ascertain the tick-borne pathogens that threaten people's health in that province, 185 tick specimens were collected from 179 patients who sought medical advice at health-care centres. The ticks were identified, and their DNA examined by PCR for pathogens. Most ticks were collected in autumn and spring (59 and 57 respectively). Nine species of ticks were identified, the most frequent being Dermacentor marginatus (55.7%), Ixodes ricinus (12.4%) and Rhipicephalus bursa (11.9%). Ninety-seven females, 66 males, 21 nymphs and one larva were identified. Twenty-six ticks carried DNA from Rickettsia spp. (11 Rickettsia slovaca, 6 Rickettsia spp. RpA4/DnS14, 1 Rickettsia massiliae/Bar29, and 8 unidentified); two ticks carried DNA from Borrelia burgdorferi sensu lato and seven ticks harboured DNA from Anaplasma phagocytophilum.     

Ticks and tick-borne rickettsiae from dogs in El Salvador,with report of the human pathogen Rickettsia parkeri

Twelve tick species have been reported in El Salvador; however, information regarding ticks infesting domestic dogs is lacking, and pathogenic tick-borne Rickettsia species have never been reported in El Salvador. This work evaluated ticks infesting 230 dogs from ten municipalities in El Salvador from July 2019 to August 2020. A total of 1,264 ticks were collected and identified into five species: Rhipicephalus sanguineus sensu lato (s.l.), Rhipicephalus microplus, Amblyomma mixtum, Amblyomma ovale, and Amblyoma cf. parvum. The tick R. sanguineus s.l. was the most frequent species in all localities (81.3% of sampled dogs), followed by Amblyomma mixtum (13.0%), Amblyomma ovale (10.9%) and Amblyomma cf. parvum (10.4%). The overall mean intensity of tick infestation was 5.5 ticks/dog. The highest specific mean intensity value was for R. sanguineus s.l. (4.8 ticks/dog), varying from 1.6 to 2.7 ticks/dog for the three Amblyomma species. From a random sample of 288 tick specimens tested molecularly for the presence of rickettsial agents, three spotted fever group Rickettsia were detected: Rickettsia amblyommatis in 90% (36/40) A. mixtum, 46% (11/24) A. cf. parvum, 4% (7/186) R. sanguineus s.l., and 17% Amblyomma spp.; Rickettsia parkeri strain Atlantic rainforest in 4% (1/25) A. ovale; and an unnamed rickettsia agent, designated as ‘Rickettsia sp. ES-A.cf.parvum’, in 4% (1/24) A. cf. parvum. Our finding of R. parkeri strain Atlantic rainforest in A. ovale is highly relevant because this agent has been associated to spotted fever illness in other Latin American countries, where A. ovale is implicated as its main vector. These findings suggest that spotted fever cases caused by R. parkeri strain Atlantic rainforest could be occurring in El Salvador.     

内蒙古部分边境口岸地区主要蜱类及蜱媒病原检测

目的 调查内蒙古主要陆地边境口岸地区蜱的种群分布、构成和自然感染病原体情况.方法 采用人工/小时布旗法和宿主体上搜法采集蜱标本,PCR法进行病原检测.结果 在被调查的策克、满都拉、满洲里3个口岸地区共采集蜱1313只,隶属于1科4属7种.草原革蜱在3个口岸均有分布,策克口岸获蜱占69.08%、蜱种多(6种)、短小扇头蜱为该口岸的优势种占74.86%.3个口岸地区共检测出5种蜱传疾病病原体,其中贝氏斯柯氏体仅在策克检出;平均感染率依次为莱姆病螺旋体15.08%、人巴贝西原虫3.35%、斑点热群立克次体1.98%、贝氏斯柯氏体1.07%、埃立克体0.99%.蜱感染莱姆病螺旋体阳性率在上述3个口岸地区均较高,分别为13.56%、22.88%、5.00%,且地区间差异有统计学意义;人巴贝两原虫、斑点热群立克次体地区间阳性率差异有统计学意义.结论 莱姆病螺旋体等5种蜱媒病原在策克、满都拉、满洲里口岸地区有不同程度自然感染.     

Detection of Rickettsia tamurae-like and other spotted fever group rickettsiae in ticks (Acari: Ixodidae) associated with wild birds in the Western Amazon,Brazil

Ticks are vectors for several pathogens, including bacteria belonging to the Rickettsia genus, such as Rickettsia rickettsii and Rickettsia parkeri, the causative agents of spotted fever. The aim of the present study was to investigate the tick species richness and rickettsial agents associated with wild birds captured in the Humaita Forest Reserve, Acre, in the Western Amazon region. Wild birds were captured with ornithological nets for visual inspection with the purpose of collecting ticks, which were identified through morphological analyses and molecular tests for several genes (12S rDNA, 16S rDNA, gltA, ompA, and sca4). A total of 607 wild birds were captured, 12% of which were parasitized by 268 ticks of the Amblyomma genus, with new host-parasite associations reported for Amblyomma calcaratum, Amblyomma geayi, Amblyomma longirostre, Amblyomma naponense, Amblyomma nodosum, and Amblyomma varium. Of the total ticks collected, 113 were tested for the presence of rickettsial DNA fragments, with 19 testing positive for R. parkeri in A. geayi, Rickettsia tamurae-like in Amblyomma sp., and Rickettsia amblyommatis in A. geayi, A. longirostre, and Amblyomma sp. We detected R. tamurae-like in Amblyomma larvae for the first time in the Western Brazilian Amazon biome, and registered spotted fever group rickettsiae, although the relevance of the detected species in a public health context should be further explored in South America, as well as new host-parasite interactions in this underexplored region.     

Identification and distribution of nine tick-borne spotted fever group Rickettsiae in the Country of Georgia

Rickettsial pathogens cause diseases that vary in severity and clinical presentation. Rickettsia species transmitted by ticks are mostly classified within the spotted fever group of rickettsiae (SFGR) and are often associated with febrile diseases. Preliminary studies have detected three human-pathogenic SFGR from ticks in Georgia: Rickettsia aeschlimannii, Rickettsia raoultii, and Rickettsia slovaca. To more broadly assess the presence of tick-borne rickettsiae from Georgia we examined 1594 ticks, representing 18 species from five genera (Ixodes, Hyalomma, Haemaphysalis, Dermacentor, and Rhipicephalus), collected from eight regions of Georgia. A total of 498 tick DNA samples extracted from single ticks or pooled ticks were assessed by molecular methods. Genus-specific Rick17b and species-specific qPCR assays were used to identify six rickettsiae: R. aeschlimannii, R. raoultii, R. slovaca, Rickettsia conorii subsp. conorii, Rickettsia massiliae, and Rickettsia monacensis. Tick samples that were positive for Rickettsia, but not identified by the species-specific assays, were further evaluated by multi-locus sequence typing (MLST) using sequences of four protein-coding genes (gltA, ompA,ompB, sca4). Three additional Rickettsia species were identified by MLST: Candidatus Rickettsia barbariae, Rickettsia helvetica, and Rickettsia hoogstraalii. Overall, nine species of Rickettsia (six human pathogens and three species with unknown pathogenicity) were detected from 12 tick species of five different genera. A distribution map for the tick-borne rickettsiae revealed six newly identified endemic regions in Georgia.     

Spotted fever group rickettsiae in ticks, Morocco

A total of 370 ticks, encompassing 7 species from 4 genera, were collected during 2002-2006 from domestic animals and vegetation in the Taza region of northeastern Morocco. Rickettsial DNA was identified in 101 ticks (27%) by sequencing PCR products of fragments of the citrate synthase and outer membrane protein genes of Rickettsia spp. Seven rickettsiae of the spotted fever group were identified, including 4 pathogens: R. aeschlimannii in Hyalomma marginatum marginatum, R. massiliae in Rhipicephalus sanguineus, R. slovaca in Dermacentor marginatus, and R. monacensis in Ixodes ricinus. Two suspected pathogens were also detected (R. raoultii in D. marginatus and R. helvetica in I. ricinus). An incompletely described Rickettsia sp. was detected in Haemaphysalis spp. ticks.     

海南省琼中地区家畜体表寄生蜱的调查分析

目的了解家畜体表寄生蜱物种多样性及群落结构特点，并分析其与疾病的关系。方法采用逆毛式检蜱法，定义家畜体表寄生蜱为一个群落，运用生态学中相对优势度（组成比率）、优势指数、多样性指数和均匀度等方法进行测定。结果从放养的5群东山羊（20头）、4群黄牛（10头）和水牛（5头）中共检获蜱2614只，分属4个种属（血红扇头蜱、微小牛蜱、粒形硬蜱和钝刺血蜱），前两者为优势种；其中东山羊的优势度指数、多样性指数和均匀度等均高于黄牛和水牛。结论海南琼中地区家畜体表寄生蜱有4种，优势种为血红扇头蜱和微小牛蜱；其中东山羊的群落结构最丰富。应警惕斑点热群立克次体自然疫源性疾病的流行。     

Rickettsiae and rickettsioses in Portugal

The only rickettsiae recorded in Portugal till now were Rickettsia conorii and Coxiella burnetii. Boutonneuse fever is one of the most important transmissible diseases in Portugal. Though the annual number of cases is not exactly known, it is estimated to be not far from 20,000 in some years. Q fever is the other rickettsiosis widely disseminated throughout the country. The serological prevalence and the incidence of those rickettsioses in Portugal are presented in this communication. In recent research in southern Portugal, about 4,000 adult ticks of nine species were screened by the haemocyte test for rickettsiae and rickettsia-like organisms (RLO). In addition to R. conorii three microscopically different RLO were observed. Two of them, i.e. ovoid and bacillary-like, were positive in the immunofluorescence test with spotted fever (R. conorii) antiserum. The first occurred mainly in Rhipicephalus sanguineus ticks, the second one also in other tick species. The latter agent was cultivated in half-engorged R. sanguineus females and in Vero cells. The third organism was found in R. sanguineus, where it exhibited a massive infestation in haemocytes resembling that seen in experimentally infected ticks with C. burnetii, but not being this agent. The investigation of the isolates and their identification and characterization are being continued.Presented at the 4th International Symposium on Rickettsiae and Rickettsial Diseases, Pietany, C.S.F.R., 1–6 October, 1990.     

Rickettsia raoultii-like Bacteria in Dermacentor spp. Ticks, Tibet, China

TO THE EDITOR: Rickettsia raoultii is an obligate intracellular gram-negative bacterium belonging to the spotted fever group (SFG) of the genus Rickettsia. Genotypes RpA4, DnS14, and DnS28, originally isolated from ticks from Russia in 1999 (1), were designated as Rickettsia raoultii sp. nov. on the basis of phylogenetic analysis (2). R. raoultii has been found mainly in Dermacentor spp. ticks in several countries in Europe (3). It was detected in a Dermacentor marginatus tick from the scalp of a patient with tick-borne lymphadenitis in France (2), which suggests that it might be a zoonotic pathogen. We determined the prevalence of R. raoultii-like bacteria in Dermacentor spp. in highland regions in Tibet.     

The brown dog tick Rhipicephalus sanguineus sensu Roberts, 1965 across Australia: Morphological and molecular identification of R. sanguineus s.l. tropical lineage

The brown dog tick Rhipicephalus sanguineus (Latreille, 1806) is the most widely distributed tick species globally. Throughout the world there are at least two divergent lineages on dogs that are traditionally grouped into what was known as R. sanguineus. The species R. sanguineus was recently redescribed using a neotype reported from countries with a temperate climate. The second lineage distributed in countries with primarily tropical climates is currently designated R. sanguineus s.l. tropical lineage. Here, we present a comprehensive genetic evaluation of Australian brown dog ticks from across the continent that complements the morphological study of R. sanguineus sensu Roberts (1965). A total of 294 ticks were collected from dogs around Australia ― including New South Wales, Queensland, the Northern Territory and Western Australia ― for morphological identification. All ticks were morphologically identified as R. sanguineus sensu Roberts (1965). DNA was isolated from a single leg from morphologically characterised individuals from New South Wales (n = 14), Queensland (n = 18), Northern Territory (n = 7) and Western Australia (n = 13), together with ticks from Fiji (n = 1) and the Seychelles (n = 1) for comparison with Australian ticks. The study revealed three cox1 haplotypes clustered only with R. sanguineus s.l. tropical lineage’. An updated distribution of R. sanguineus sensu Roberts (1965) is compared to the 1965 distribution. In the Australian context, R. sanguineus s.l. has appeared in north-western New South Wales but remains absent from coastal New South Wales. Despite both temperate and tropical climates being present in Australia, only R. sanguineus s.l. tropical lineage was found. The evidence does not support the presence of the strictly defined brown dog tick, R. sanguineus by Nava et al. (2018) in Australia, because the examined ticks are genetically and morphologically distinct. We recommend using the term brown dog tick, R. sanguineus sensu Roberts (1965) for specimens from Australia.     

Questions on Mediterranean spotted fever a century after its discovery

Mediterranean spotted fever (MSF) was first described in 1910. Twenty years later, it was recognized as a rickettsial disease transmitted by the brown dog tick. In contrast to Rocky Mountain spotted fever (RMSF), MSF was thought to be a benign disease; however, the first severe case that resulted in death was reported in France in the 1980s. We have noted important changes in the epidemiology of MSF in the last 10 years, with emergence and reemergence of MSF in several countries. Advanced molecular tools have allowed Rickettsia conorii conorii to be classified as a subspecies of R. conorii. New clinical features, such as multiple eschars, have been recently reported. Moreover, MSF has become more severe than RMSF; the mortality rate was as high as 32% in Portugal in 1997. Whether Rhipicephalus sanguineus is the only vector and reservoir for R. conorii conorii is a question not yet answered.     

Diversity and geographic distribution of rickettsial agents identified in brown dog ticks from across the United States

Rhipicephalus sanguineus sensu lato, or brown dog ticks, transmit a variety of pathogens of veterinary and public health importance globally. Pathogens vectored by brown dog ticks and identified in the United States include Babesia vogeli, Ehrlichia canis, and several spotted fever group Rickettsia spp. (SFGR). Due to the challenge of collecting canine blood samples nationwide to screen for exposure to these pathogens, we took an indirect approach and tested brown dog ticks for molecular evidence of infection. Brown dog ticks (616 adults and 65 nymphs) collected from dogs and cats across the nation were tested by separate PCR assays detecting Babesia spp., E. canis, and SFGR. While no Babesia sp. was found, we identified rickettsial agents in 3.5% (24/681; 95% CI 2.4–5.2%) of the ticks. Pathogens and related organisms detected in ticks included E. canis (n = 1), Rickettsia amblyommatis (n = 3), Rickettsia massiliae (n = 11), Rickettsia monacensis (n = 3), Rickettsia montanensis (n = 5), and an undefined Rickettsia species (n = 1). These data demonstrate a wider geographic distribution of R. massiliae than previously known, and to the authors’ knowledge, reports R. monacensis in brown dog ticks for the first time. Due to the close association that brown dog ticks have with domestic dogs and humans, more research is needed to understand the full array of organisms, some of which are zoonotic, potentially transmitted by this widespread tick complex.     

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。     

Molecular detection of a novel Babesia sp. and pathogenic spotted fever group rickettsiae in ticks collected from hedgehogs in Turkey: Haemaphysalis erinacei,a novel candidate vector for the genus Babesia

In this study, a total of 319 ticks were obtained from hedgehogs (Erinaceus concolor). All ticks were pooled into groups and screened by PCR for tick-borne pathogens (TBPs). PCR and sequence analyses identified the presence of a novel Babesia sp. in adult Haemaphysalis erinacei. In addition, the presence of natural transovarial transmission of this novel Babesia sp. was detected in Ha. erinacei. According to the 18S rRNA (nearly complete) and partial rRNA locus (ITS-1/5.8S/ITS-2) phylogeny, it was determined that this new species is located within the Babesia sensu stricto clade and is closely related to Babesia spp. found in carnivores. Furthermore, the presence of three pathogenic spotted fever group (SFG) rickettsiae was determined in 65.8% of the tick pools: Rickettsia sibirica subsp. mongolitimonae in Hyalomma aegyptium (adult), Hyalomma spp. (larvae), Rhipicephalus turanicus (adult), and Ha. erinacei (adult); Rickettsia aeschlimannii in H. aegyptium (adult); Rickettsia slovaca in Hyalomma spp. (larvae and nymphs) and H. aegyptium (adult). To our knowledge, this is the first report of R. sibirica mongolitimonae in H. aegyptium, Ha. erinacei, and Rh. turanicus, and the first report of R. slovaca in H. aegyptium. In addition, the presence of a single Hemolivia mauritanica haplotype was detected in H. aegyptium adults. Consequently, the presence of a novel Babesia sp. has been identified in a new candidate vector tick species in this study. Additionally, three SFG rickettsiae that cause infections in humans were identified in ticks collected from hedgehogs. Therefore, environmental wildlife monitoring for hedgehogs should be carried out for ticks and tick-borne pathogens in the region. Additionally, studies regarding the reservoir status of hedgehogs for the aforementioned pathogens must be carried out.     

塔里木盆地蜱类群落组成和分布

目的 掌握塔里木盆地蜱类群落的组成和分布规律。方法 按照地理区划和生境类型选择调查点进行蜱类种类和数量调查，采用群落生态学技术方法，计算不同生态环境条件下的蜱类群落组成。结果 在塔里木盆地共采获蜱类5属9种，以亚东璃眼蜱（Hyalomma asiaticum kozlovi）和亚洲璃眼蜱指名亚种（Hyalomma asiaticum asiaticum）为优势种类，分别占35．8％和33．6％。但在不同地区和生态环境的蜱类群落组成有所不同。叶尔羌河流域及北部塔里木河中上游地区蜱类种类丰富，共采获5属8种，占捕获总种数的88．9％。游离蜱指数较塔里木东部和南部低，分别为30．47、84．30和85．31，寄生蜱指数高，分别为15．19、10．10和10.85。璃眼蜱属蜱类以亚东璃眼蜱为主，占92．0％，亚洲璃眼蜱占有很少比例，为5．8％，寄生蜱以图兰扇头蜱（Rhipicephalus turanicus）为主，但较塔里木东部和南部低，分别为55．8％、65．8％和74．7％，血红扇头蜱（Rhipicephalus sanguineus）仅占很小的比例，占0．2％；塔里木盆地东部和南部蜱类群落组成基本一致，均为2属5种，较西北部少。游离蜱指数明显较西北部高，寄生蜱指数低。游离蜱中亚洲璃眼蜱指名亚种在南部地区占主要地位，为72．6％，而在东部地区以亚东璃眼蜱为主，为66．9％，存在25％左右的交叉，寄生蜱中以图兰扇头蜱为主，并较西北部的比例偏高，血红扇头蜱的比例达10％左右，与银盾革蜱（Dermacentor niveus）基本一致，较西北部高出20倍左右。结论 塔里木盆地蜱类动物地理区划在宏观上是基本一致的，但在不同地理景观和生态环境中蜱类的群落结构却存在极大的差异。     

2010年中蒙边境甘其毛都口岸地区蜱携带病原体调查研究

目的为了解中蒙边境蜱传疾病病原体携带情况,对2010年中蒙联合监测小组在内蒙古乌拉特中旗甘其毛都口岸地区采集的162只亚东璃眼蜱进行病原体检测。方法采用RT-PCR法检测蜱标本中的森林脑炎病毒、克里米亚-刚果出血热病毒、布尼亚病毒,PCR方法检测蜱标本中的伯氏疏螺旋体、西伯利亚立克次体、贝氏柯克斯体,嗜吞噬细胞无形体。结果森林脑炎病毒、克里米亚-刚果出血热病毒、布尼亚病毒、嗜吞噬细胞无形体检测结果均为阴性,PCR方法检出5例伯氏疏螺旋体、3例西伯利亚立克次体、16例贝氏柯克斯体,检出率分别为3.7%、2.2%和11.9%,并发现2例伯氏疏螺旋体和贝氏柯克斯体复合感染的情况。结论中蒙边境地区蜱携带伯氏疏螺旋体、贝氏柯克斯体和西伯利亚立克次体等病原体,应有针对性地加强当地蜱类和蜱传疾病的监测和防控。