江西省赣州市蜱携带立克次体和埃立克体的调研

目的 了解江西省赣州市蜱的种类及其携带的病原体,为蜱传疾病的防控提供科学依据方法 在野外用布旗法和在动物体表采集蜱,进行种类鉴定。用PCR法扩增立克次体(Rickettsia sp.)gltA基因和埃立克体(Ehrlichia sp.)16S rRNA基因片段并测序,进行系统进化分析结果 江西省赣州市4县采集的395只蜱的种类包括2属4种,分别为血蜱属的长角血蜱(Haemaphysalislongicornis)、嗜群血蜱(H. concinna)、具角血蜱(H. cornigera)和扇头蜱属的微小扇头蜱(Rhipicephalus microplus)。395只蜱分为43批检测立克次体和埃立克体,共有18批阳性。系统进化分析显示,龙南县22批蜱中检测到16批阳性,来源于具角血蜱的LN1615株与扇头蜱立克次体(R. rhipicephali)处于同一分支,来源于微小扇头蜱的LN1620株与马赛立克次体(R. massiliae)处于同一分支,其余的12株来源于具角血蜱和2株来源于微小扇头蜱,与日本立克次体(R. japonica)处于同一分支。崇义县CY1602株来源于嗜群血蜱与R. raoultii处于同一分支。于都县YD1606株为来源于长角血蜱的埃立克体,与2010年Yonaguni206(HQ697589)、Yonaguni138(HQ697588)和2009年HLAE178(GU075695)处于同一分支。安远县微小扇头蜱检测均为阴性结论 本文对江西省赣州市采集的蜱进行了鉴定,首次在江西省赣州市的蜱中检测到日本立克次体、扇头蜱立克次体、马赛立克次体、R. raoultii和埃立克体,为江西省蜱种类的调查及其传播疾病的预防控制提供根据。     

黑河口岸地区蜱类调查及研究

目的 调查分析黑河口岸地区蜱种类多样性。方法 对2012年至2014年黑龙江省黑河区域内蜱种群密度、数量、分布以及季节变迁方面的数据进行整理及总结,通过形态学的观察及PCR检测明确黑河地区蜱的分类及携带病原体情况。结果 黑河口岸地区的蜱类采集活动中,共获得蜱类1 343只,经鉴定分属3属3种,其中森林革蜱1 054只,占总体构成78.48%,为优势蜱种;嗜群血蜱236只,占总体构成17.57%;全沟硬蜱53只,占总体构成3.94%。之后本试验对采集到的1 343只蜱针对10种病原体进行PCR检测。在黑河地区的蜱类中,森林革蜱的立克次体感染率为64.37%、巴尔通体感染率为3.35%、类似巴贝西虫病原体检出率为1.70%,其他相关蜱虫病原检测结果为阴性。结论 森林革蜱为试验采集蜱虫中的优势蜱种;进行病原体检查发现立克次体具有较高感染率,其中病原体主要在森林革蜱中发现,森林革蜱仍然是监测新发蜱媒传染病的前哨种类。携带的病原体的种类随着生态环境的变化在慢慢发生变化,边境的生态环境复杂多样,在蜱虫比较活跃繁多的地区和季节应该增大防范措施,以免人们在工作以及生活中被其感染,从而造成生命财产损失。     

Illumina MiSeq对热带环境血蜱属成蜱内共生真菌多样性分析

目的 探讨海南热带环境血蜱属成蜱内共生真菌的群落组成及多样性分析。方法 对成蜱样本进行形态学分类,扩增线粒体COI基因进行分子鉴定;应用Illumina MiSeq平台对血蜱属内共生真菌ITS1基因进行高通量测序,以OTU聚类分析、Alpha多样性分析阐明内共生真菌群落组成及多样性。结果 热带环境游离血蜱属内共生真菌聚类为245个OTU;群落组成分布于子囊菌门(Ascomycota)占80.56%、担子菌门(Basidiomycota)占15.43%及接合菌门(Zygomycota)占0.37%;优势菌种为Zasmidium citrigriseum,占7.72%。Alpha多样性分析表明,血蜱属内共生真菌具有十分丰富的生物多样性。结论 热带环境血蜱属成蜱内共生真菌多样性的研究,可为揭示蜱与内共生真菌复杂的互作关系提供依据,为进一步阐明热带蜱的行为特征并探索有效的生物学防控策略提供新思路。     

内蒙古大兴安岭林区牙克石段的蜱种及蜱携病原体感染调查

目的 调查内蒙古东部大兴安岭林区牙克石段的蜱种分布及病原体感染状况。方法 2016-2019年,在东部林区蜱活跃高峰期(5-6月)采用布旗法采集游离蜱标本,使用体视显微镜对蜱初步分类;提取蜱全基因组DNA,采用斑点热立克次体、无形体属、埃立克体属、莱姆病螺旋体和新型回归热螺旋体病原体的特异性基因进行PCR检测。结果 本次共采集蜱虫2 786只,通过体视显微镜和基因检测分析,隶属于1科3属4种,分别为全沟硬蜱(Ixodes persulcatus)、嗜群血蜱(Haemaphysalinae concinna)、日本血蜱(Haemaphysalinae japonica)、森林革蜱(Dermacentor silvarum)。其中,全沟硬蜱(78.6%,2 191/2 786)、嗜群血蜱(15.9%,442/2 786)为本地区的优势蜱种。在大兴安岭林区牙克石段的7个采样地区的蜱中,乌奴耳镇斑点热立克次体检出率最高,为74.2%(222/299);博克图镇无形体属检出率较高,为18.9%(39/206);库都尔镇埃立克体属、莱姆病螺旋体、新型回归热螺旋体的检出率均较高,分别为26.1%(12/46)、76.1%(35/46)、13.0%(6/46)。除新型回归热螺旋体外,其他4种病原体的检出率雄蜱均高于雌蜱(P<0.05);成蜱的无形体、埃立克体、莱姆病螺旋体检出率均高于幼蜱(P<0.05)。大兴安岭林区牙克石段蜱的复合感染率为19.5%(544/2 786)。其中,免渡河镇蜱携2种病原体复合感染率为40.6%(186/458),乌奴耳镇蜱携3种及以上病原体复合感染率分别是47.4%(36/76)、90%(9/10)。结论 大兴安岭林区牙克石段共存在4种蜱,蜱携莱姆病螺旋体最普遍,其中免渡河镇和乌奴耳镇的蜱普遍携带多种病原体,需重点加强该地区蜱媒传染病的监测和预防。     

云南临沧地区蜱种分子生物学鉴定及埃立克体基因序列分析

目的 了解云南临沧地区蜱虫种类及其自然感染埃立克体的情况。方法 采集耕牛体表寄生的蜱虫,经形态学鉴定和分组后,从蜱虫中提取DNA,应用PCR扩增蜱虫COI基因以及埃立克体16S rRNA和groEL基因,并测序分析。结果 共采集到蜱虫42只,其中微小牛蜱38只占90.48%、血蜱4只占9.52%。将每种蜱的2只为1组,在21组样本中,检出COI片断21份(检出率100%);在相同的4组样本中均检出埃立克体16S rRNA片断和groEL片断4份(检出率19.05%)。基因序列分析,检出的COI片断序列中有2份与澳大利亚pava血蜱(JX573136)的同源性最高(89.3%),其余19份序列与马来西亚微小牛蜱B3的同源性最高(99.5%);检出的4份16S rRNA片断序列完全一致,与美国查菲埃立克体Arkansas和埃文埃立克体Aa2FT349及中国北京查菲埃立克体BY-YQ-HME-O18株的同源性均为100%;检出的4份groEL片断序列也完全一致,与日本埃立克体Yonaguni206 株的同源性最高均为93.9%。结论 经分子检测证实云南临沧地区耕牛体表微小牛蜱中存在一种类似日本Yonaguni206株的埃立克体感染,耕牛体表还可能寄生一种新的血蜱。     

北京市首例莱姆病合并斑点热混合感染确诊病例的流行病学调查分析

目的 分析北京市首例莱姆病合并斑点热混合感染确诊病例的流行病学特征,为蜱传疾病防控工作提供科学依据。方法 通过现场流行病学个案调查,了解患者活动史、发病就诊过程, 临床表现以及实验室检测结果,并对其进行分析。结果 调查结果提示北京市郊可能存在莱姆病和斑点热重叠自然疫源地。结论 本起疫情是北京市首例莱姆病合并斑点热混合感染确诊病例,建议在相关地区开展人群和病媒生物监测,明确莱姆病和斑点热疫区范围,警惕人群感染蜱传疾病的风险。     

COI基因DNA条形码技术在福建省蜱类鉴定中的应用

目的 探讨基于线粒体细胞色素C氧化酶亚基I(COI)基因的DNA条形码技术应用于福建省蜱类鉴定的可行性。方法 蜱标本经形态学鉴定后提取基因组DNA,PCR扩增COI基因片段,并进行测序和比对,用Kimura-2-parameter模型计算种内及种间遗传距离,以邻接法构建系统发育树。结果 经形态学鉴定,97只蜱隶属于5属12种,遗传距离计算结果显示,种间遗传距离(14.65%~26.79%)显著大于种内遗传距离(0~7.14%);BLAST同源性比对发现GenBank数据库中尚无越原血蜱(Haemophysalis Yeni)与基刺硬蜱(Ixodes spinicoxalis)的COI基因序列,褐黄血蜱(H.flava)、台岛血蜱(H.formosensis)、豪猪血蜱(H.hystricis)、粒形硬蜱(I.granulatus)、微小扇头蜱(Rhipicephalus microplus)与血红扇头蜱(R.sanguineus)的形态学鉴定与DNA条形码鉴定结果一致,但是,龟形花蜱(Amblyomma testudinarium)、台湾革蜱(Dermacentor taiwanensis)、中华硬蜱(I.sinensis)的形态学鉴定与COI基因DNA条形码鉴定结果不一致;系统发育树显示,同一物种的不同个体均形成高支持率的单系,种间分支很明显。结论 COI基因DNA条形码测定是一种快速准确的蜱类鉴定新兴技术,但现阶段,COI基因DNA条形码技术尚不能完全脱离传统的形态学鉴定而独立进行,两者应有机结合。     

新疆克拉玛依地区蜱媒病原体的调查

目的 调查新疆克拉玛依地区蜱种类及其携带病原体。方法 于克拉玛依市不同区采集游离蜱和寄生蜱,鉴定蜱种类,利用荧光定量PCR或套氏PCR/半套氏PCR检测发热伴血小板减少综合征布尼亚病毒、斑点热群立克次体、克里米亚-刚果出血热病毒、蜱传脑炎病毒、巴贝斯虫/泰勒虫、贝氏立克次体、查菲埃立克次体、恙虫病东方体和伯氏疏螺旋体等9种病原体。结果 共采集蜱683只,分3属3种,其中亚东璃眼蜱数量(n=362)最多,其次为银盾革蜱(n=311)、图兰扇头蜱(n=10)。银盾革蜱中斑点热群立克次体的阳性率为3.2%(10/311),巴贝斯虫的阳性率为1.0%(3/311);亚东璃眼蜱中巴贝斯虫的阳性率为0.8%(3/362),泰勒虫阳性率为0.3%(1/362);其他病原体检测结果均呈阴性。PCR扩增阳性基因序列分析显示银盾革蜱携斑点热群立克次体阳性与劳氏立克次体最相关,银盾革蜱和亚东璃眼蜱携带驽巴贝斯虫。结论 新疆克拉玛依地区优势蜱为亚东璃眼蜱和银盾革蜱,银盾革蜱携带劳氏立克次体,银盾革蜱和亚东璃眼蜱携带驽巴贝斯虫,提示该地区存在斑点热、巴贝斯虫病的自然疫源地,因此有必要加强对这些蜱携疾病的防控。     

内蒙古部分地区草原革蜱携带无形体检测与进化分析

目的 探究内蒙古地区草原革蜱无形体感染情况,鉴定蜱传无形体种属并进行系统进化分析。方法 基于无形体16S rRNA基因、groEL基因和MSP4基因合成特异引物,对内蒙古地区采集的蜱虫标本进行PCR扩增,将阳性样本进行测序和分析并构建系统发育进化树。结果 将采集的905只蜱虫经形态学鉴定后将168只饱血蜱与737只未饱血蜱分为220个蜱虫混合样本,经检测有41个无形体阳性样本均来自于单只饱血蜱样本,总阳性检出率为4.53%(41/905),其中呼伦贝尔地区阳性率为1.03%(3/292);赤峰地区阳性率为3.13%(17/543);鄂尔多斯地区阳性率为30%(21/70),Blast比对分析结果显示与绵羊无形体同源性高达99%以上。系统发育进化树和同源性比对分析结果显示内蒙古地区16S rRNA基因的序列与新疆绵羊无形体xjmns03(JN400674)同源性最高,为99.49%;groEL基因序列与苏丹青尼罗州绵羊无形体G-BN-40(MG383903)同源性最高,为98.77%;MSP4基因序列与与陕西绵羊无形体D/SX786(MN307493)同源性最高,为100.00%。结论 内蒙古地区存在蜱传绵羊无形体,鄂尔多斯地区阳性率最高,为避免蜱传疾病对动物及人类健康造成危害,应重点对鄂尔多斯地区进行科学防控。     

我国蜱和人群中TBEV流行情况的Meta分析

目的 通过评价蜱、人群中蜱传脑炎病毒阳性率及血清抗体阳性率的情况,分析蜱传脑炎在我国的流行特点,明确我国现行蜱传脑炎预防控制措施疫苗接种的重要意义,为该病的预防控制提供科学依据。方法 检索PubMed、万方、维普和知网数据库搜集2000-2019年发表的关于蜱中蜱传脑炎病毒阳性率和人血清学调查的文章,通过Meta分析方法利用Stata15软件对选定的11篇和12篇相关文献进行汇总和分析,得到蜱传脑炎在我国蜱和人群中的流行特点。结果 2000-2019年我国TBEV阳性蜱主要分布在吉林、黑龙江和内蒙古。不同蜱种中TBEV阳性率不同,森林革蜱中TBEV阳性率最高为5%(95%CI:2%~10%,P<0.05)。人群特征分析显示:男性抗体阳性率高于女性,林区工人、军人和农民易感染。不同地区人群血清抗体阳性率差异很大,新疆地区的抗体阳性率最高为14%(95%CI:9%~21%,P<0.05)。结论 我国TBEV流行多在东北地区,阳性蜱以森林草蜱为主,感染人群多为林区工人、军人和农民。     

Ixodes ricinus density and infection prevalence of Borrelia burgdorferi sensu lato along a North-facing altitudinal gradient in the Rhône Valley (Switzerland)

Questing Ixodes ricinus ticks were sampled monthly along a north-facing altitudinal gradient in the canton of Valais, Switzerland, from March 2004 to February 2005. Tick density and infection with Borrelia burgdorferi sensu lato were monitored. Ticks were collected by flagging vegetation at three different altitudes (750 m, 880 m, and 1020 m above sea level). Ticks were examined for Borrelia by polymerase chain reaction (PCR) followed by reverse line blot. At the three altitudes, questing tick activity was not observed under 10 degrees C and was reduced when saturation deficit was higher than 5 mm Hg, most questing tick activity was occurred between 2 mm Hg and 7 mm Hg. Tick density and peak tick density were highest at 1020 m. High saturation deficits at the lowest altitudes appear to impair the tick population. The prevalence of B. burgdorferi infection in nymphs and adults decreased with altitude. The prevalence of infection was higher in adult ticks (47%) than in nymphs (29%). Four B. burgdorferi sensu lato genospecies were detected: B. afzelii (40%), B. garinii (22%), B. valaisiana (12%) and B. burgdorferi sensu stricto (6%). Mixed infections were detected in 13% of infected ticks.     

Seasonality of Ixodes ricinus ticks on vegetation and on rodents and Borrelia burgdorferi sensu lato genospecies diversity in two lyme borreliosis-endemic areas in Switzerland

We compared Ixodes ricinus questing density, the infestation of rodents by immature stages, and the diversity of Borrelia burgdorferi sensu lato (sl) in questing ticks and ticks collected from rodents in two Lyme borreliosis (LB)-endemic areas in Switzerland (Portes-Rouges [PR] and Staatswald [SW]) from 2003 to 2005. There were variations in the seasonal pattern of questing tick densities among years. Questing nymphs were globally more abundant at PR than at SW, but the proportion of rodents infested by immature ticks was similar (59.4% and 61%, respectively). Questing tick activity lasted from February to November with a strong decline in June. The seasonal pattern of ticks infesting rodents was different. Ticks infested rodents without decline in summer, suggesting that the risk of being bitten by ticks remains high during the summer. Rodents from SW showed the highest infestation levels (10±21.6 for larvae and 0.54±1.65 for nymphs). The proportion of rodents infested simultaneously by larvae and nymphs (co-feeding ticks) was higher at SW (28%) than at PR (11%). Apodemus flavicollis was the species the most frequently infested by co-feeding ticks, and Myodes glareolus was the most infective rodent species as measured by xenodiagnosis. At PR, the prevalence of B. burgdorferi sl in questing ticks was higher (17.8% for nymphs and 32.4% for adults) than at SW (10.4% for nymphs and 24.8% for adults), with B. afzelii as the dominant species, but B. garinii, B. burgdorferi sensu stricto, and B. valaisiana were also detected. Rodents transmitted only B. afzelii (at PR and at SW) and B. bavariensis (at SW) to ticks, and no mixed infection by additional genospecies was observed in co-feeding ticks. This implies that co-feeding transmission does not contribute to genospecies diversity. However, persistent infections in rodents and co-feeding transmission contribute to the perpetuation of B. afzelii in nature.     

Prevalence of Borrelia burgdorferi sensu lato in Ixodes ricinus population in forests of north-western Poland

The ticks Ixodes ricinus were collected during three growing seasons in forested areas of north-western Poland. The ticks were collected by flagging at 30 sites. The specimens collected (nymphs and adults) were subjected, after an appropiate treatment, to indirect immunofluorescence analysis (IFA). In addition, effects of temperature and atmospheric precipitation on the tick infection with the spirochaete Borrelia burgdorferi were investigated based on data supplied by the Institute of Meteorology. A total of 8519 individuals of I. ricinus were collected at the sampling sites within May-October of three consecutive years. The pool of individuals obtained consisted of 7356 nymphs, 559 females, and 604 males. The B. burgdorferri prevalence varied rather widely, from 10 to 19%. Compared to nymphs, adult individuals showed a higher infection rate. A relationship between infection rate and I. ricinus activity in different years and months was studied in detail. The boreliosis risk was found to increase with increasing tick activity. On the other hand, no correlation was found between the meteorological parameters (temperature, precipitation), tick abundance, and the B. burgdorferi infection rate.     

Density of questing Ixodes ricinus nymphs and adults infected by Borrelia burgdorferi sensu lato in Switzerland: spatio-temporal pattern at a regional scale

Lyme borreliosis, the most important vector-borne disease in the Northern hemisphere, causes health problem for populations in endemic areas. In the present study, the density of questing Ixodes ricinus ticks and their infection with Borrelia burgdorferi sensu lato (sl) was examined in 11 areas located on the Swiss Plateau and in an alpine valley. From 1999 to 2001, free-living I. ricinus ticks were collected on a monthly basis by flagging vegetation in these areas. Each tick was examined for the presence of B. burgdorferi sl using direct fluorescent antibody assay, and for isolation of the bacteria. Borreliae were characterized by PCR followed by RFLP. Density of questing ticks varied greatly between studied areas. Borreliae were observed in ticks collected in all investigated sites. However, the prevalence of infection differed significantly among areas. Infection prevalence varied from 9% to 40% in nymphs and from 22% to 47% in adults. Adult ticks were significantly more infected (129/366, 35%) than nymphs (109/552, 20%). There was no correlation between nymphal density and infection prevalence as well as between adult density and infection prevalence, but there was a correlation between density of ticks and density of infected ticks. During the spring peak of questing tick density, a range of 2-30.3 infected ticks per 100 m(2) was observed. B. burgdorferi sl isolates (n = 129) were obtained from ticks collected in 10/11 areas. Five Borrelia species were identified: B. garinii, B. burgdorferi sensu stricto, B. afzelii, B. valaisiana, B. lusitaniae, and six mixed infections were also obtained. Borrelia species were heterogeneously distributed in the different areas.     

Temporal variation of Ixodes ricinus intensity on the rodent host Apodemus flavicollis in relation to local climate and host dynamics

The risk to humans of contracting tick-borne zoonotic diseases depends on the risk of a bite from an infected tick, which can be broken down into its component parts as the number of host-seeking ticks in the environment, in particular nymphs, and the prevalence of tick-borne pathogens they are carrying. In turn, the prevalence of tick-borne pathogens is dependent upon tick biting intensity on hosts that support transmission between ticks; namely rodents. These ticks once fed moult into the next life stage and search for the next blood meal, thus posing a zoonotic risk. Here, we analyse tick biting intensity on rodents in a known tick-borne encephalitis (TBE) focus in Trentino (northern Italy). We examine patterns of tick demography and the influence of host densities and climate on ticks' generation time, development rates, tick density and intensity. During the period 2000-2004, a population of the yellow-necked mouse, Apodemus flavicollis, the most important TBE transmission host, was intensively monitored. Ticks feeding on individual rodents were counted, distinguishing between the larval and nymph life-stages. Local temperature and relative humidity was calculated using both data-loggers in the field site and regional weather stations. We investigated which factors had a predictive value both on feeding tick intensity and on the overall density of larvae or nymphs feeding on rodents in a year. We observed a negative effect of rodent density on tick intensity, while temperature influenced positively both larvae and nymph intensity. Overall larval density was higher in the years and trapping grids where rodent density was higher, while for nymphs no such effect was observed. The best explanatory variable for nymph density was the larval density in the previous year, confirming the discrete nature of tick demography. This provides important information in terms of monitoring the risk to humans of acquiring pathogen-infected ticks.     

Geographic and temporal variations in population dynamics of Ixodes ricinus and associated Borrelia infections in The Netherlands

In a countrywide investigation of the ecological factors that contribute to Lyme borreliosis risk, a longitudinal study on population dynamics of the sheep tick Ixodes ricinus and their infections with Borrelia burgdorferi sensu lato (s.l.) was undertaken at 24 sites in The Netherlands from July 2006 to December 2007. Study sites were mature forests, dune vegetations, or new forests on land reclaimed from the sea. Ticks were sampled monthly and nymphal ticks were investigated for the presence of Borrelia spp. I. ricinus was the only tick species found. Ticks were found in all sites, but with significant spatial and temporal variations in density between sites. Peak densities were found in July and August, with lowest tick numbers collected in December and January. In some sites, questing activities of I. ricinus nymphs and adults were observed in the winter months. Mean monthly Borrelia infections in nymphs varied from 0% to 29.0% (range: 0%-60%), and several sites had significantly higher mean nymphal Borrelia infections than others. Four genospecies of Borrelia burgdorferi s.l. were found, with B. afzelii being dominant at most sites. Borrelia infection rates in nymphal ticks collected in July, September, and November 2006 were significantly higher (23.7%, p<0.01) than those in the corresponding months of 2007 (9.9%). The diversity in Borrelia genospecies between sites was significantly different (p<0.001). Habitat structure (tree cover) was an effective discriminant parameter in the determination of Borrelia infection risk, as measured by the proportion of nymphal ticks infected with B. burgdorferi s.l. Thickness of the litter layer and moss cover were positively related to nymphal and adult tick densities. The study shows that Borrelia-infected ticks are present in many forest and dune areas in The Netherlands and suggests that in such biotopes, which are used for a wide variety of recreational activities, the infection risk is high.     

Questing ticks in suburban forest are infected by at least six tick-borne pathogens

The role of Ixodes ricinus ticks in the transmission of pathogens of public health importance such as Borrelia burgdorferi s.l. is widely recognized and is suspected in several emerging vector-borne pathogens in Europe. Here, we assess prevalence rates of several endemic and emerging zoonotic pathogens in tick populations in an area of high human population density in France, to contribute to a risk assessment for potential transmission to humans. Pathogen prevalence rates were evaluated by polymerase chain reaction detection and sequencing in questing ticks, individually for adults and in pools of 10 for nymphs. In addition to finding micro-organisms corresponding to symbionts, we found high prevalence rates of B. burgdorferi s.l. (32% of adult females and 10% of nymphs) and low to moderate ones of Anaplasma phagocytophilum (~1%), spotted fever group Rickettsia spp. (~6%), Babesia sp. EU1 (~1%), Bartonella birtlesii (0.1%), and Francisella tularensis (!1%). Our findings extend the knowledge of the geographical distribution of these endemic and emergent pathogens and support the conclusion that ticks are important vectors of pathogenic micro-organisms in suburban forests. Moreover, tick coinfection with multiple pathogens was found to occur frequently, which poses a serious challenge for diagnosis and appropriate treatment. The incrimination of these pathogens in potentially severe pathologies requires widespread surveillance to assess the risk of infection, thereby facilitating diagnosis and treatment, as well as raising local awareness of tick-borne diseases.     

Ticks infesting wild and domestic animals and humans of Sri Lanka with new host records

An island-wide collection of tick species infesting humans, domesticated and wild animals and questing ticks in domestic and peridomestic environments was carried out during 2009–2011. A total of 30,461 ticks were collected from 30 different hosts and free living stages from the ground. The collection consisted of 22 tick species from 30 different hosts recording 12 tick species from humans, 19 from domesticated animals and 21 from wild animals, with a total of 97 new host records. The most common tick species on humans were Dermacentor auratus and Amblyomma testudinairum, while Haemaphysalis intermedia, Rhipicephalus microplus and Rhipicephalus sanguineus were common in domesticated and wild animals sharing 20 host species. Among the questing ticks, immature D. auratus was the most abundant. Humans and domesticated animals were mostly infested by the nymphal stages while adult ticks were found on wild animals. High number of new host records could be due to domestic animals picking tick species from wildlife and vise versa at the human/animal interface. Habitat destruction due to forest fragmentation has lead to wild animals roaming in urban and semi-urban neighbourhoods increasing the interactions of wild animals with domesticated animals. Wild animals play a significant role as a reservoir of many tick borne infections which can easily be spread to domesticated animals and then to humans via tick infestations. Data in this paper are useful for those interested in tick infesting wild and domestic animals and humans in describing the zoonotic potential of tick borne infections.     

Endothelial function fluctuates with diurnal variation in the frequency of ischemic episodes in patients with variant angina

OBJECTIVES: The aim of the present study was to investigate whether there is diurnal fluctuation in the endothelial function of patients with variant angina (VA). BACKGROUND: Coronary spasm is induced by acetylcholine and is promptly relieved by nitroglycerin. Thus, it is possible that endothelial dysfunction is involved in the pathogenesis of coronary spasm. Furthermore, the frequency of ischemic episodes is known to display diurnal variation. METHODS: Flow-mediated, endothelium-dependent vasodilation of the brachial arteries was measured in the early morning (6 AM), afternoon (2 PM) and evening (8 PM) in 20 patients with VA (mean age 54.5 years; 10 men and 10 women) and in 20 control subjects (mean age 54.2 years; 10 men and 10 women). All patients underwent 24-h ambulatory electrocardiographic monitoring during the study. RESULTS: Flow-mediated vasodilation in patients with VA was deteriorated by the early morning and improved by the afternoon (patients with VA at 8 PM vs. 6 AM vs. 2 PM: 7.8 +/- 2.1% (p < 0.01 vs. VA at 6 AM) vs. 5.4 +/- 2.3% vs. 8.8 +/- 1.9% (p < 0.01 vs. VA at 6 AM); control subjects: 9.5 +/- 2.8% vs. 9.0 +/- 2.2% vs. 9.9 +/- 1.9%, respectively). The frequency of spontaneous ischemic episodes was highest from midnight to morning and was lowest from morning to late afternoon (4 PM to midnight: 7 episodes; midnight to 8 AM: 25 episodes; 8 AM to 4 PM: 3 episodes). CONCLUSION: There is diurnal fluctuation in endothelial function, which is associated with variation in the frequency of ischemic episodes.     

Feeding by the tick, Ixodes scapularis, causes CD4(+) T cells responding to cognate antigen to develop the capacity to express IL-4

Effects of tick feeding on an early antigen-specific T cell response were studied by monitoring a clonotypic population of adoptively transferred T cell receptor (TCR) transgenic CD4 cells responding to a tick-associated antigen. When recipient mice were infested with pathogen-free Ixodes scapularis nymphs several days prior to T cell transfer and intradermal injection of soluble cognate antigen at the feeding site, the clonotypic CD4 cells gained the ability to express the Th2 effector cytokine IL-4. Notably, this effect was not only observed in BALB/c mice predisposed towards developing Th2 responses but also in B10.D2 mice predisposed towards Th1 responsiveness. Furthermore, tick feeding was able to superimpose IL-4 expression potential onto a strong Th1 response (indicated by robust IFN-gamma expression potential) elicited by immunization with a vaccinia virus expressing the cognate antigen. The magnitude to which tick feeding was able to programme IL-4 expression potential in CD4 cells was partially reduced in mice that had been previously exposed to pathogen-free tick nymphs 6 weeks earlier, as well as when the nymphs were infected with Borrelia burgdorferi. Intradermal injection of salivary gland extract programmed IL-4 expression potential similar to that of tick infestation, suggesting that IL-4 programming activity is contained within tick saliva.