Publications

TitleAbstractYear
Filter
PMID
Filter
granulocytic anaplasmosis in three dogs from saskatoon, saskatchewan.three dogs from saskatoon, saskatchewan were diagnosed with acute granulocytic anaplasmosis. fever, lethargy, inappetence, vomiting, diarrhea, and lameness were reported. lymphopenia, thrombocytopenia, and splenomegaly were identified in all dogs. inclusions were identified within the cytoplasm of blood neutrophils, and infection with anaplasma phagocytophilum was confirmed by polymerase chain reaction.200919881921
survival rates of immature ixodes pacificus (acari: ixodidae) ticks estimated using field-placed enclosures.granulocytic anaplasmosis (ga) and lyme borreliosis are emerging tick-borne diseases caused by infection with anaplasma phagocytophilum and borrelia burgdorferi, respectively, and maintained in rodent-ixodes spp. tick cycles, including i. pacificus in the western u.s. ixodes pacificus has a multiple-year life cycle and b. burgdorferi and a. phagocytophilum are transstadially, but not transovarially, transmitted within ticks, thus ticks function importantly in maintaining infection in nature. in ...201020618646
detection of lyme disease spirochete, borrelia burgdorferi sensu lato, including three novel genotypes in ticks (acari: ixodidae) collected from songbirds (passeriformes) across canada.lyme disease is reported across canada, but pinpointing the source of infection has been problematic. in this three-year, bird-tick-pathogen study (2004-2006), 366 ticks representing 12 species were collected from 151 songbirds (31 passerine species/subspecies) at 16 locations canada-wide. of the 167 ticks/pools tested, 19 (11.4%) were infected with borrelia burgdorferi sensu lato (s.l.). sequencing of the rrf-rrl intergenic spacer gene revealed four borrelia genotypes: b. burgdorferi sensu stri ...201020618658
comparative microarray analysis of rhipicephalus (boophilus) microplus expression profiles of larvae pre-attachment and feeding adult female stages on bos indicus and bos taurus cattle.rhipicephalus (boophilus) microplus is an obligate blood feeder which is host specific to cattle. existing knowledge pertaining to the host or host breed effects on tick transcript expression profiles during the tick - host interaction is poor.201020637126
effect of climate change on lyme disease risk in north america.an understanding of the influence of climate change on ixodes scapularis, the main vector of lyme disease in north america, is a fundamental component in assessing changes in the spatial distribution of human risk for the disease. we used a climate suitability model of i. scapularis to examine the potential effects of global climate change on future lyme disease risk in north america. a climate-based logistic model was first used to explain the current distribution of i. scapularis in north amer ...200519008966
lyme disease vaccine. 200018159278
a spatially-explicit model of acarological risk of exposure to borrelia burgdorferi-infected ixodes pacificus nymphs in northwestern california based on woodland type, temperature, and water vapor.in the far-western united states, the nymphal stage of the western black-legged tick, ixodes pacificus, has been implicated as the primary vector to humans of borrelia burgdorferi sensu stricto (hereinafter referred to as b. burgdorferi), the causative agent of lyme borreliosis in north america. in the present study, we sought to determine if infection prevalence with b. burgdorferi in i. pacificus nymphs and the density of infected nymphs differ between dense-woodland types within mendocino cou ...201020532183
impact of the experimental removal of lizards on lyme disease risk.the distribution of vector meals in the host community is an important element of understanding and predicting vector-borne disease risk. lizards (such as the western fence lizard; sceloporus occidentalis) play a unique role in lyme disease ecology in the far-western united states. lizards rather than mammals serve as the blood meal hosts for a large fraction of larval and nymphal western black-legged ticks (ixodes pacificus-the vector for lyme disease in that region) but are not competent reser ...201121325326
lysophosphatidylcholine: a novel modulator of trypanosoma cruzi transmission.lysophosphatidylcholine is a bioactive lipid that regulates a large number of cellular processes and is especially present during the deposition and infiltration of inflammatory cells and deposition of atheromatous plaque. such molecule is also present in saliva and feces of the hematophagous organism rhodnius prolixus, a triatominae bug vector of chagas disease. we have recently demonstrated that lpc is a modulator of trypanosoma cruzi transmission. it acts as a powerful chemoattractant for inf ...201222132309
genetic diversity of borrelia burgdorferi and detection of b. bissettii-like dna in serum of north-coastal california residents.in north america, lyme borreliosis (lb) is a tick-borne disease caused by infection with the spirochete borrelia burgdorferi. we studied the genetic diversity of lb spirochetes in north-coastal california residents. spirochete dna was detected in 23.7% (27/114) of the study subjects using a pcr protocol optimized for increased sensitivity in human sera. californians were most commonly infected with b. burgdorferi ospc genotype a, a globally widespread spirochete associated with high virulence in ...201021177909
differential impact of west nile virus on california birds.the strain of west nile virus (wnv) currently epidemic in north america contains a genetic mutation elevating its virulence in birds, especially species in the family corvidae. although dead american crows (corvus brachyrhynchos) have been the hallmark of the epidemic, the overall impact of wnv on north america's avifauna remains poorly understood and has not been addressed thoroughly in california. here, we evaluate variation by species in the effect of wnv on california birds from 2004 to 2007 ...200920589226
Seroprevalence of Borrelia burgdorferi, Anaplasma phagocytophilum, Ehrlichia canis, and Dirofilaria immitis among dogs in Canada.The seropositivity of dogs to Borrelia burgdorferi, Anaplasma phagocytophilum, and Ehrlichia canis antibodies, and Dirofilaria immitis antigen was assessed in Canada. Borrelia burgdorferi had the highest seroprevalence, while that of Dirofilaria immitis has not changed significantly in the past 20 y. The risk for these vector-borne infectious agents in Canadian dogs is low but widespread with foci of higher prevalence.201122043075
Infection prevalences of common tick-borne pathogens in adult lone star ticks (Amblyomma americanum) and American dog ticks (Dermacentor variabilis) in Kentucky.Rocky Mountain spotted fever, Lyme disease, and ehrlichiosis are tick-borne diseases that are reported annually in Kentucky. We conducted a survey to describe infection prevalence of tick-borne pathogens in Amblyomma americanum and Dermacentor variabilis ticks collected in Kentucky. During 2007-2008, we collected 287 ticks (179 D. variabilis and 108 A. americanum) from canine, feral hog, horse, raccoon, white-tailed deer, and human hosts in six counties in Kentucky. Ticks were screened for Ricke ...201121976578
subversion of complement by hematophagous parasites.the complement system is a crucial part of innate and adaptive immunity which exerts a significant evolutionary pressure on pathogens. it has selected for those pathogens, mainly microorganisms but also parasites, that have evolved countermeasures. the characterization of how pathogens evade complement attack is a rapidly developing field of current research. in recent years, multiple complement evasion strategies have been characterized. in this review, we focus on complement escape mechanisms ...200918762211
of ticks, mice and men: understanding the dual-host lifestyle of lyme disease spirochaetes.in little more than 30 years, lyme disease, which is caused by the spirochaete borrelia burgdorferi, has risen from relative obscurity to become a global public health problem and a prototype of an emerging infection. during this period, there has been an extraordinary accumulation of knowledge on the phylogenetic diversity, molecular biology, genetics and host interactions of b. burgdorferi. in this review, we integrate this large body of information into a cohesive picture of the molecular and ...201222230951
differences in prevalence of borrelia burgdorferi and anaplasma spp. infection among host-seeking dermacentor occidentalis, ixodes pacificus, and ornithodoros coriaceus ticks in northwestern california.previous studies revealed that the pacific coast tick (dermacentor occidentalis) is infected occasionally with the agents of lyme disease (borrelia burgdorferi) or human granulocytic anaplasmosis (anaplasma phagocytophilum) and that it is an inefficient experimental vector of b. burgdorferi. the relationship of the pajahuello tick (ornithodoros coriaceus) to each of these bacterial zoonotic agents has not been reported. the primary bridging vector of both bacterial zoonotic agents to humans is t ...201021359090
evolution, expansion and expression of the kunitz/bpti gene family associated with long-term blood feeding in ixodes scapularis.abstract: background: recent studies of the tick saliva transcriptome have revealed the profound role of salivary proteins in blood feeding. kunitz/bpti proteins are abundant in the salivary glands of ticks and perform multiple functions in blood feeding, such as inhibiting blood coagulation, regulating host blood supply and disrupting host angiogenesis. however, kunitz/bpti proteins in soft and hard ticks have different functions and molecular mechanisms. how these differences emerged and whet ...201222244187
multilocus sequence analysis of borrelia bissettii strains from north america reveals a new borrelia species, borrelia kurtenbachii.using multilocus sequence analyses (mlsa), we investigated the phylogenetic relationship of spirochaete strains from north america previously assigned to the genospecies borrelia bissettii. we amplified internal fragments of 8 housekeeping genes (clpa, clpx, nifs, pepx, pyrg, recg, rplb, and uvra) located on the main linear chromosome by polymerase chain reaction. phylogenetic analysis of concatenated sequences of the 8 loci showed that the b. bissettii clade consisted of 4 closely related clust ...201021157575
diverse borrelia burgdorferi strains in a bird-tick cryptic cycle.the blacklegged tick ixodes scapularis is the primary vector of the most prevalent vector-borne zoonosis in north america, lyme disease (ld). enzootic maintenance of the pathogen borrelia burgdorferi by i. scapularis and small mammals is well documented, whereas its "cryptic" maintenance by other specialist ticks and wildlife hosts remains largely unexplored because these ticks rarely bite humans. we quantified b. burgdorferi infection in a cryptic bird-rabbit-tick cycle. furthermore, we explore ...201121257811
effects of an invasive forest pathogen on abundance of ticks and their vertebrate hosts in a california lyme disease focus.invasive species, including pathogens, can have important effects on local ecosystems, including indirect consequences on native species. this study focuses on the effects of an invasive plant pathogen on a vertebrate community and ixodes pacificus, the vector of the lyme disease pathogen (borrelia burgdorferi) in california. phytophthora ramorum, the causative agent of sudden oak death, is a non-native pathogen killing trees in california and oregon. we conducted a multi-year study using a grad ...201020941513
human granulocytic anaplasmosis: first reported case in canada.human granulocytic anaplasmosis (hga) is a tick-borne rickettsial infection of peripheral blood neutrophils caused by anaplasma phagocytophilum. while this infection is increasingly recognized as endemic throughout much of the united states, no canadian cases have been previously described, despite the agent being identified in canadian ticks. herein we present a case of hga acquired in an urban alberta centre. canadian physicians must be aware of the possibility of tick-borne rickettsial diseas ...200920808448
natural product studies of u.s. endangered plants: volatile components of lindera melissifolia (lauraceae) repel mosquitoes and ticks.the number of endangered plant species in the u.s. is significant, yet studies aimed towards utilizing these plants are limited. ticks and mosquitoes are vectors of significant pathogenic diseases of humans. repellents are critical means of personal protection against biting arthropods and disease transmission. the essential oil and solvent extracts from lindera melissifolia (walt.) blume (lauraceae) (pondberry) drupes were gathered and analyzed by gc and gc-ms. the essential oil obtained from t ...201222704653
novel exposure sites for nymphal ixodes pacificus within picnic areas.risk of exposure to nymphal ixodes pacificus cooley and kohls ticks was investigated at 7 picnic areas in tilden regional park, a heavily used recreation area of over 2000 acres in northwestern california, east of san francisco bay. wooden picnic tables, tree trunks, logs, leaf litter, surrounding vegetation, and rock walls were checked for ticks using standard 1-m(2) flannel tick flags at biweekly intervals from march to august 2008. results indicate that nymphal i. pacificus were commonly foun ...201122108011
increasing incidence of ehrlichia chaffeensis and anaplasma phagocytophilum in the united states, 2000-2007.ehrlichia chaffeensis causes human monocytic ehrlichiosis, and anaplasma phagocytophilum causes human granulocytic anaplasmosis. these related tick-borne rickettsial organisms can cause severe and fatal illness. during 2000-2007, the reported incidence rate of e. chaffeensis increased from 0.80 to 3.0 cases/million persons/year. the case-fatality rate was 1.9%, and the hospitalization rate was 49%. during 2000-2007, the reported incidence of a. phagocytophilum increased from 1.4 to 3.0 cases/mil ...201121734137
mechanisms of obligatory intracellular infection with anaplasma phagocytophilum.anaplasma phagocytophilum persists in nature by cycling between mammals and ticks. human infection by the bite of an infected tick leads to a potentially fatal emerging disease called human granulocytic anaplasmosis. a. phagocytophilum is an obligatory intracellular bacterium that replicates inside mammalian granulocytes and the salivary gland and midgut cells of ticks. a. phagocytophilum evolved the remarkable ability to hijack the regulatory system of host cells. a. phagocytophilum alters vesi ...201121734244
clinical manifestations of tick-borne infections in children. 200010882645
lyme disease vaccine. 200020177519
the dusky-footed woodrat (neotoma fuscipes) is susceptible to infection by anaplasma phagocytophilum originating from woodrats, horses, and dogs.the dusky-footed woodrat (neotoma fuscipes) is the putative reservoir for anaplasma phagocytophilum in the western united states based on high prevalence of a. phagocytophilum genetic material detected by polymerase chain reaction (pcr), high antibody prevalence, and infestation with the vector tick ixodes pacificus. following inoculation of nine wild-caught woodrats with woodrat-, canine-, or equine-origin a. phagocytophilum, all became pcr-positive and seroconverted. however, when pcr-positive ...201020688687
host specialization in ticks and transmission of tick-borne diseases: a review.determining patterns of host use, and the frequency at which these patterns change, are of key importance if we are to understand tick population dynamics, the evolution of tick biodiversity, and the circulation and evolution of associated pathogens. the question of whether ticks are typically host specialists or host generalists has been subject to much debate over the last half-century. indeed, early research proposed that morphological diversity in ticks was linked to host specific adaptation ...201324109592
nidicolous ticks of small mammals in anaplasma phagocytophilum-enzootic sites in northern california.ixodes spp. tick-borne zoonotic diseases are present across the holarctic in humans, domestic animals, and wildlife. small mammals are reservoirs for the rickettsial pathogen anaplasma phagocytophilum and tick vectors may include catholic-feeding bridge vectors as well as host-specialist or nidicolous ticks. far western north american communities in which a. phagocytophilum is maintained are complex ecologically, with multiple reservoir host and tick species, multiple strains of the bacterial pa ...201121686062
lyme disease: a zoonotic disease of increasing importance to canadians. 200818854461
geographic differences in genetic locus linkages for borrelia burgdorferi.borrelia burdorferi genotype in the northeastern united states is associated with lyme borreliosis severity. analysis of dna sequences of the outer surface protein c gene and rrs-rrla intergenic spacer from extracts of ixodes spp. ticks in 3 us regions showed linkage disequilibrium between the 2 loci within a region but not consistently between regions.201020587192
larval keys to the genera of ixodidae (acari) and species of ixodes (latreille) ticks established in california.in california, hard (ixodidae) ticks transmit at least 8 zoonotic disease agents (1 virus, 6 bacteria, 1 protozoan) to humans or other animals. the correct taxonomic identification of all 3 parasitic stages (larvae, nymphs, adults) of ticks is integral to understanding host-tick associations and disease dynamics, but immature ticks, especially the larvae, can be difficult to identify. here, we present larval keys to the 4 genera of ixodidae (dermacentorkoch, 1844; haemaphysaliskoch, 1844; ixodes ...200820027236
the emergence of lyme disease in canada. 200919506281
lyme disease in canada: q & a for paediatricians. 200920514158
lyme disease in canada: q & a for paediatricians. 200919436561
brief, recurrent, and spontaneous episodes of loss of consciousness in a healthy young male.lyme disease is caused by bacterial spirochete borrelia burgdorferi and is transmitted by ixodes scapularis and ixodes pacificus ticks, which get infected while feeding on the reservoir host of the bacteria.1 about 248,074 cases of lyme disease were reported by the us centers for disease control and prevention from 1992-2006.2 over 95% of these cases are reported from the northeastern and upper midwestern united states.3 carditis is usually a clinical manifestation/complication of lyme disease a ...201023754893
tick cell culture isolation and growth of rickettsia raoultii from dutch dermacentor reticulatus ticks.tick cell lines play an important role in research on ticks and tick-borne pathogenic and symbiotic microorganisms. in an attempt to derive continuous dermacentor reticulatus cell lines, embryo-derived primary cell cultures were set up from eggs laid by field ticks originally collected as unfed adults in the netherlands and maintained for up to 16 months. after several months, it became evident that cells in the primary cultures were infected with a rickettsia-like intracellular organism. supern ...201223140894
analysis of an ordered, comprehensive stm mutant library in infectious borrelia burgdorferi: insights into the genes required for mouse infectivity.the identification of genes important in the pathogenesis of lyme disease borrelia has been hampered by exceedingly low transformation rates in low-passage, infectious organisms. using the infectious, moderately transformable b. burgdorferi derivative 5a18np1 and signature-tagged versions of the himar1 transposon vector pgkt, we have constructed a defined transposon library for the efficient genome-wide investigation of genes required for wild-type pathogenesis, in vitro growth, physiology, morp ...201223133514
evolving perspectives on lyme borreliosis in canada.with cases now documented in every province, lyme borreliosis (lb) is emerging as a serious public health risk in canada. controversy over the contribution of lb to the burden of chronic disease is maintained by difficulty in capturing accurate canadian statistics, especially early clinical cases of lb. the use of dogs as sentinel species demon-strates that potential contact with borrelia burgdorferi spirochetes, as detected by c6 peptide, extends across the country. dissemination of infected ti ...201223091570
two boundaries separate borrelia burgdorferi populations in north america.understanding the spread of infectious diseases is crucial for implementing effective control measures. for this, it is important to obtain information on the contemporary population structure of a disease agent and to infer the evolutionary processes that may have shaped it. here, we investigate on a continental scale the population structure of borrelia burgdorferi, the causative agent of lyme borreliosis (lb), a tick-borne disease, in north america. we test the hypothesis that the observed po ...201222729536
borrelia burgdorferi infections in the united states.it is becoming increasingly evident that the clinical presentation of infection with borrelia burgdorferi varies greatly between different parts of the world. a growing number of european and asian isolates of lyme borreliae, differing from the american strain of borrelia burgdorferi, have been identified in several different disorders. in light of the increasing number of reports describing an association between various cutaneous disorders and infection with borrelia burgdorferi and the contro ...201222916311
impacts of an introduced forest pathogen on the risk of lyme disease in california.global changes such as deforestation, climate change, and invasive species have the potential to greatly alter zoonotic disease systems through impacts on biodiversity. this study examined the impact of the invasive pathogen that causes sudden oak death (sod) on the ecology of lyme disease in california. the lyme disease bacterium, borrelia burgdorferi, is maintained in the far western united states by a suite of animal reservoirs including the dusky-footed woodrat (neotoma fuscipes) and deer mo ...201222607076
association of bartonella spp bacteremia with chagas cardiomyopathy, endocarditis and arrhythmias in patients from south america.infection with bartonella spp may cause cardiac arrhythmias, myocarditis and endocarditis in humans. the aim of the present study was to evaluate a possible association between bartonella spp bacteremia and endocarditis, arrhythmia and chagas cardiomyopathy in patients from brazil and argentina. we screened for the presence of bacterial 16s rrna in human blood by pcr using oligonucleotides to amplify a 185-bp bacterial dna fragment. blood samples were taken from four groups of subjects in brazil ...201222584639
lyme disease: knowledge, beliefs, and practices of physicians in a low-endemic area.to determine physicians' level of awareness and knowledge of lyme disease (ld) in a low-prevalence area and whether physicians' practices align with current guidelines for treatment of ld.201222734172
clinical findings and diagnosis in human granulocytic anaplasmosis: a case series from massachusetts.to describe clinical findings and the use of a tick-associated pathogen panel in a series of patients with human granulocytic anaplasmosis (hga) at a suburban boston hospital.201222386178
field studies on lyme disease in north america.the primary tick vector of borrelia burgdorferi in eastern and central north america is ixodes dammini; in western north america, ixodes pacificus. searching for the appropriate vector is the first step in determining whether a region is endemic and enzootic for the spirochete b burgdorferi, the etiological agent of lyme disease, followed by examination of the ticks (questing or already attached to hosts) and wildlife for the spirochete. questing ticks can be collected through a variety of metho ...199122529709
consensus conference on lyme disease. 199122529708
need for improved methods to collect and present spatial epidemiologic data for vectorborne diseases.improved methods for collection and presentation of spatial epidemiologic data are needed for vectorborne diseases in the united states. lack of reliable data for probable pathogen exposure site has emerged as a major obstacle to the development of predictive spatial risk models. although plague case investigations can serve as a model for how to ideally generate needed information, this comprehensive approach is cost-prohibitive for more common and less severe diseases. new methods are urgently ...200718258029
the relapsing fever spirochete borrelia miyamotoi is cultivable in a modified kelly-pettenkofer medium, and is resistant to human complement.borrelia miyamotoi is a relapsing fever spirochete found in ixodes ticks in north america, europe, and asia, and has recently been found to be invasive in humans. cultivation of this spirochete has not yet been described, but is important for patient diagnostics and scientific purposes. host specificity of borrelia species is dependent on resistance to host complement (serum resistance), and since b. miyamotoi has been identified as a human pathogen we were interested whether b. miyamotoi is res ...201425189195
the laboratory diagnosis of lyme borreliosis: guidelines from the canadian public health laboratory network.lyme borreliosis is uncommonly seen in canada. most cases have occurred in close proximity to small geographical areas where infected ticks have become established. although few cases are seen, thousands of patients are tested yearly. unless patients are carefully selected and an appropriately sensitive and specific testing algorithm is applied, large numbers of patients without lyme borreliosis will be incorrectly diagnosed. the canadian public health laboratory network has developed the presen ...200718923770
tick salivary compounds: their role in modulation of host defences and pathogen transmission.ticks require blood meal to complete development and reproduction. multifunctional tick salivary glands play a pivotal role in tick feeding and transmission of pathogens. tick salivary molecules injected into the host modulate host defence responses to the benefit of the feeding ticks. to colonize tick organs, tick-borne microorganisms must overcome several barriers, i.e., tick gut membrane, tick immunity, and moulting. tick-borne pathogens co-evolved with their vectors and hosts and developed m ...201323971008
lyme disease in canada: focus on children.lyme disease, the most common tick-borne infection in canada and much of the united states, is caused by the bacteria borrelia burgdorferi. peak incidence for lyme disease is among children five to nine years of age and older adults (55 to 59 years of age). the bacteria are transmitted through the bite of infected black-legged ticks of the ixodes species. the primary hosts of black-legged ticks are mice and other rodents, small mammals, birds (which are reservoirs for b burgdorferi) and white-ta ...201425332678
comparison of a real-time pcr method with serology and blood smear analysis for diagnosis of human anaplasmosis: importance of infection time course for optimal test utilization.anaplasmosis and ehrlichiosis are emerging tick-borne diseases with clinically similar presentations caused by closely related pathogens. currently, laboratories rely predominantly on blood smear analysis (for the detection of intracellular morulae) and on serologic tests, both of which have recognized limitations, for diagnostic purposes. we compared the performance of a published real-time pcr assay that incorporates melt curve analysis to differentiate anaplasma and ehrlichia species with blo ...201323637292
population and demographic structure of ixodes scapularis say in the eastern united states.the most significant vector of tick-borne pathogens in the united states is ixodes scapularis say (the blacklegged tick). previous studies have identified significant genetic, behavioral and morphological differences between northern vs. southern populations of this tick. because tick-borne pathogens are dependent on their vectors for transmission, a baseline understanding of the vector population structure is crucial to determining the risks and epidemiology of pathogen transmission.201425025532
avian hosts of ixodes pacificus (acari: ixodidae) and the detection of borrelia burgdorferi in larvae feeding on the oregon junco.larval and nymphal western blacklegged tick, ixodes pacificus cooley & kohls (acari: ixodidae), were collected from birds, rodents, and lizards at quail ridge reserve located in napa county in northwestern california. species from three vertebrate classes were sampled simultaneously from two transects during two consecutive spring seasons. feeding larval and nymphal ticks were removed and preserved for counting, examination and testing for the presence of borrelia burgdorferi johnson, schmid, hy ...201121845945
granulocytic anaplasmosis in a horse from nova scotia caused by infection with anaplasma phagocytophilum.a 16-year-old paint stallion was presented with intermittent fever, inappetance, lethargy, icterus, distal limb edema, and submandibular lymphadenopathy. the horse was native to nova scotia and had never left that province. morulae were detected in granulocytes. ananaplasma phagocytophilum infection was confirmed by serology and polymerase chain reaction (pcr). the horse responded to treatment with oxytetracycline.201122043078
temporal patterns of tick-borne granulocytic anaplasmosis in california.granulocytic anaplasmosis (ga) is a tick-borne emerging infectious disease caused by the bacterium anaplasma phagocytophilum. from fall 2005 to spring 2007, a. phagocytophilum infection prevalence in small mammals and tick abundance were monitored at 4 study sites in coastal california. the abundance of different life stages of questing ixodes pacificus ticks fluctuated seasonally with the number of adults peaking december to february, nymphs peaking may to july, and larvae peaking april to june ...201121771541
the use of deer vehicle accidents as a proxy for measuring the degree of interaction between human and deer populations and its correlation with the incidence rate of lyme disease.the study described in this article examined the relationship between the incidence rate of deer vehicle accidents (dvas), a proxy for measuring the interaction between populations of humans and deer, and human lyme disease incidence rate. the authors also examined the relationship between deer population density and human lyme incidence rate. they analyzed data from connecticut's department of environmental protection and the department of public health from 1999 through 2008 by deer management ...201323621054
co-infection of blacklegged ticks with babesia microti and borrelia burgdorferi is higher than expected and acquired from small mammal hosts.humans in the northeastern and midwestern united states are at increasing risk of acquiring tickborne diseases--not only lyme disease, but also two emerging diseases, human granulocytic anaplasmosis and human babesiosis. co-infection with two or more of these pathogens can increase the severity of health impacts. the risk of co-infection is intensified by the ecology of these three diseases because all three pathogens (borrelia burgdorferi, anaplasma phagocytophilum, and babesia microti) are tra ...201424940999
serum antibodies to borrelia burgdorferi, anaplasma phagocytophilum, and babesia microti in recaptured white-footed mice.a mark-release-recapture study was conducted during 2007 through 2010 in six, tick-infested sites in connecticut, united states to measure changes in antibody titers for borrelia burgdorferi sensu stricto, anaplasma phagocytophilum, and babesia microti in peromyscus leucopus (white-footed mice). there was an overall recapture rate of 40%, but only four tagged mice were caught in ≥2 yr. sera from 561 mice were analyzed for total antibodies to b. burgdorferi and a. phagocytophilum by using whole-c ...201323568904
outer surface protein c peptide derived from borrelia burgdorferi sensu stricto as a target for serodiagnosis of early lyme disease.current serodiagnostic assays for lyme disease are inadequate at detecting early infection due to poor sensitivity and nonspecificity that arise from the use of whole bacteria or bacterial proteins as assay targets; both targets contain epitopes that are cross-reactive with epitopes found in antigens of other bacterial species. tests utilizing peptides that contain individual epitopes highly specific for borrelia burgdorferi as diagnostic targets are an attractive alternative to current assays. ...201323365204
prevalence and burden of two rickettsial phylotypes (g021 and g022) in ixodes pacificus from california by real-time quantitative pcr.the western black-legged tick, ixodes pacificus cooley and kohls, commonly bites humans in the far western u.s. in addition to transmitting lyme borreliosis and anaplasmosis, it is a host of nonpathogenic bacteria as well as some of unknown pathogenicity. in this study, we report the detection, prevalence, and burden of 2 rickettsial phylotypes with unknown pathogenicity in i. pacificus ticks from 6 california counties using real-time quantitative pcr with phylotype-specific primers and probes. ...201323522936
what is the risk for exposure to vector-borne pathogens in united states national parks?united states national parks attract > 275 million visitors annually and collectively present risk of exposure for staff and visitors to a wide range of arthropod vector species (most notably fleas, mosquitoes, and ticks) and their associated bacterial, protozoan, or viral pathogens. we assessed the current state of knowledge for risk of exposure to vector-borne pathogens in national parks through a review of relevant literature, including internal national park service documents and organismal ...201323540107
vaccination against lyme disease: past, present, and future.lyme borreliosis is a zoonotic disease caused by borrelia burgdorferi sensu lato bacteria transmitted to humans and domestic animals by the bite of an ixodes spp. tick (deer tick). despite improvements in diagnostic tests and public awareness of lyme disease, the reported cases have increased over the past decade to approximately 30,000 per year. limitations and failed public acceptance of a human vaccine, comprised of the outer surface a (ospa) lipoprotein of b. burgdorferi, led to its demise, ...201323407755
comparative bioinformatics, temporal and spatial expression analyses of ixodes scapularis organic anion transporting polypeptides.organic anion-transporting polypeptides (oatps) are an integral part of the detoxification mechanism in vertebrates and invertebrates. these cell surface proteins are involved in mediating the sodium-independent uptake and/or distribution of a broad array of organic amphipathic compounds and xenobiotic drugs. this study describes bioinformatics and biological characterization of 9 oatp sequences in the ixodes scapularis genome. these sequences have been annotated on the basis of 12 transmembrane ...201424582512
vector biodiversity did not associate with tick-borne pathogen prevalence in small mammal communities in northern and central california.vector and host abundance affect infection transmission rates, prevalence, and persistence in communities. biological diversity in hosts and vectors may provide "rescue" hosts which buffer against pathogen extinction and "dilution" hosts which reduce the force of infection in communities. anaplasma phagocytophilum is a tick-transmitted zoonotic pathogen that circulates in small mammal and tick communities characterized by varying levels of biological diversity. we examined the prevalence of a. p ...201424582513
evolution and distribution of the ospc gene, a transferable serotype determinant of borrelia burgdorferi.borrelia burgdorferi, an emerging bacterial pathogen, is maintained in nature by transmission from one vertebrate host to another by ticks. one of the few antigens against which mammals develop protective immunity is the highly polymorphic ospc protein, encoded by the ospc gene on the cp26 plasmid. intragenic recombination among ospc genes is known, but the extent to which recombination extended beyond the ospc locus itself is undefined. we accessed and supplemented collections of dna sequences ...201020877579
whole-genome sequences of borrelia bissettii, borrelia valaisiana, and borrelia spielmanii.it has been known for decades that human lyme disease is caused by the three spirochete species borrelia burgdorferi, borrelia afzelii, and borrelia garinii. recently, borrelia valaisiana, borrelia spielmanii, and borrelia bissettii have been associated with lyme disease. we report the complete genome sequences of b. valaisiana vs116, b. spielmanii a14s, and b. bissettii dn127.201222207749
flab gene as a molecular marker for distinct identification of borrelia species in environmental samples by the pcr-restriction fragment length polymorphism method.a new protocol employing nested pcr-restriction fragment length polymorphism (rflp) based on the flab gene and two restriction enzymes was worked out. this protocol allows the identification of all borrelia species transmitted by ixodes ricinus in europe, including borrelia miyamotoi and 3 genetic variants of b. garinii. a dendrogram of flab sequence similarity was in accordance with rflp variants.201121841027
stage-specific global alterations in the transcriptomes of lyme disease spirochetes during tick feeding and following mammalian host adaptation.borrelia burgdorferi, the agent of lyme disease, is maintained in nature within an enzootic cycle involving a mammalian reservoir and an ixodes sp. tick vector. the transmission, survival and pathogenic potential of b. burgdorferi depend on the bacterium's ability to modulate its transcriptome as it transits between vector and reservoir host. herein, we employed an amplification-microarray approach to define the b. burgdorferi transcriptomes in fed larvae, fed nymphs and in mammalian host-adapte ...201425425211
the western progression of lyme disease: infectious and nonclonal borrelia burgdorferi sensu lato populations in grand forks county, north dakota.scant attention has been paid to lyme disease, borrelia burgdorferi, ixodes scapularis, or reservoirs in eastern north dakota despite the fact that it borders high-risk counties in minnesota. recent reports of b. burgdorferi and i. scapularis in north dakota, however, prompted a more detailed examination. spirochetes cultured from the hearts of five rodents trapped in grand forks county, nd, were identified as b. burgdorferi sensu lato through sequence analyses of the 16s rrna gene, the 16s rrna ...201425304515
borrelia burgdorferi (lyme disease). 201425452659
molecular characterization of borrelia burgdorferi from case of autochthonous lyme arthritis. 201425423131
pathogenic landscape of transboundary zoonotic diseases in the mexico-us border along the rio grande.transboundary zoonotic diseases, several of which are vector borne, can maintain a dynamic focus and have pathogens circulating in geographic regions encircling multiple geopolitical boundaries. global change is intensifying transboundary problems, including the spatial variation of the risk and incidence of zoonotic diseases. the complexity of these challenges can be greater in areas where rivers delineate international boundaries and encompass transitions between ecozones. the rio grande serve ...201425453027
the first case of locally acquired tick-borne babesia microti infection in canada.a child with a complicated medical history that included asplenia acquired an infection with babesia microti in the summer of 2013 and had not travelled outside of manitoba. although the clinical findings were subtle, astute laboratory work helped to reach a preliminary identification of babesia species, while reference laboratory testing confirmed the diagnosis. blacklegged ticks (ixodes scapularis) are known to transmit borrelia burgdorferi and anaplasma phagocytophilum in the province; howeve ...201425587297
efficacy and safety of pharmacological treatments for neuroborreliosis--protocol for a systematic review.neuroborreliosis is a tick-borne infectious disease of the nervous system caused by borrelia burgdorferi. common clinical manifestations of neuroborreliosis are cranial nerve dysfunctions, polyradiculoneuritis, and meningitis. diagnosis is usually based on clinical presentation, serologic testing, and analysis of cerebrospinal fluid. many aspects of pharmacological treatment, such as choice of drug, dosage, and duration are subject of intense debate, leading to uncertainties in patients and heal ...201425336085
large scale spatial risk and comparative prevalence of borrelia miyamotoi and borrelia burgdorferi sensu lato in ixodes pacificus.borrelia miyamotoi is a newly described emerging pathogen transmitted to people by ixodes species ticks and found in temperate regions of north america, europe, and asia. there is limited understanding of large scale entomological risk patterns of b. miyamotoi and of borreila burgdorferi sensu stricto (ss), the agent of lyme disease, in western north america. in this study, b. miyamotoi, a relapsing fever spirochete, was detected in adult (n=70) and nymphal (n=36) ixodes pacificus ticks collecte ...201425333277
evaluation of selected borrelia burgdorferi lp54 plasmid-encoded gene products expressed during mammalian infection as antigens to improve serodiagnostic testing for early lyme disease.laboratory testing for the diagnosis of lyme disease is performed primarily by serologic assays and is accurate for detection beyond the acute stage of the infection. serodiagnostic assays to detect the early stages of infection, however, are limited in their sensitivity, and improvement is warranted. we analyzed a series of borrelia burgdorferi proteins known to be induced within feeding ticks and/or during mammalian infection for their utility as serodiagnostic markers against a comprehensive ...201526376927
first isolation of the relapsing fever spirochete, borrelia hermsii, from a domestic dog.in north america, tick-borne relapsing fever of humans is most frequently caused by infection with the spirochete borrelia hermsii. prior to our investigation, this spirochete was not known to infect dogs although another species, borrelia turicatae, has been isolated from domestic canids in florida and texas. a clinically ill dog in washington, usa, was spirochetemic upon examination. spirochetes were isolated from the dog's serum and examined by pcr and multi-locus sequence typing. dna sequenc ...201324252262
single-tube real-time pcr assay for differentiation of ixodes affinis and ixodes scapularis.ixodes affinis neumann (1899) and ixodes scapularis say (1821) are tick vectors of the etiologic agent of lyme disease, borrelia burgdorferi sensu stricto. ixodes affinis and i. scapularis are morphologically very similar, and as they are sympatric in the mid- and south-atlantic u.s. coastal states, their accurate identification is crucial to studies of disease and vector ecology in this area. this work describes a rapid, single-tube sybr(®) green-based real-time pcr assay for differentiation of ...201324192510
multilocus sequence typing of borrelia burgdorferi suggests existence of lineages with differential pathogenic properties in humans.the clinical manifestations of lyme disease, caused by borrelia burgdorferi, vary considerably in different patients, possibly due to infection by strains with varying pathogenicity. both rrna intergenic spacer and ospc typing methods have proven to be useful tools for categorizing b. burgdorferi strains that vary in their tendency to disseminate in humans. neither method, however, is suitable for inferring intraspecific relationships among strains that are important for understanding the evolut ...201324069170
temporal and spatial variation in anaplasma phagocytophilum infection in swedish moose (alces alces).the occurrence of anaplasma phagocytophilum was investigated in spleen and serum samples from swedish moose (alces alces) in southern sweden (island and mainland). samples were analysed for presence of a. phagocytophilum dna by real-time pcr (n = 263), and for anaplasma antibodies with elisa serology (n = 234). all serum samples had antibodies against a. phagocytophilum. the mean dna-based prevalence was 26·3%, and significant (p < 0·01) temporal, and spatial variation was found. island moose ha ...201324001524
irspi, a tick serine protease inhibitor involved in tick feeding and bartonella henselae infection.ixodes ricinus is the most widespread and abundant tick in europe, frequently bites humans, and is the vector of several pathogens including those responsible for lyme disease, tick-borne encephalitis, anaplasmosis, babesiosis and bartonellosis. these tick-borne pathogens are transmitted to vertebrate hosts via tick saliva during blood feeding, and tick salivary gland (sg) factors are likely implicated in transmission. in order to identify such tick factors, we characterized the transcriptome of ...201425057911
a 24-48 h fed amblyomma americanum tick saliva immuno-proteome.multiple tick saliva proteins, the majority of which are unknown, confer tick resistance in repeatedly infested animals. the objective of this study was to identify the 24-48 h fed amblyomma americanum tick saliva immuno-proteome. the 24-48 h tick-feeding phase is critical to tick parasitism as it precedes important events in tick biology, blood meal feeding and disease agent transmission. fed male, 24 and 96 h fed female phage display cdna expression libraries were biopanned using rabbit antibo ...201424962723
emergence of ixodes scapularis and borrelia burgdorferi, the lyme disease vector and agent, in ohio.lyme disease, the most common vector-borne disease in the united states, is caused by a tick-borne infection with borrelia burgdorferi. currently, ohio is considered by the centers for disease control and prevention (cdc) to be non-endemic for lyme disease. the low incidence of lyme disease in this state was largely attributed to the absence of the transmitting vector, ixodes scapularis, commonly known as the blacklegged tick. however, a tick surveillance program established by ohio department o ...201424926441
case 2: a seven-year-old girl with diplopia. 201425382993
serum antibodies to whole-cell and recombinant antigens of borrelia burgdorferi in cottontail rabbits.archived serum samples, from 95 eastern cottontail rabbits (sylvilagus floridanus) captured in new york, new york, usa and millbrook, new york, usa, during 1985-86, were analyzed in solid-phase enzyme-linked immunosorbent assays (elisa) for total and class-specific immunoglobulin (ig) m antibodies to whole-cell or recombinant antigens of borrelia burgdorferi sensu stricto. using a polyvalent conjugate, rabbit sera contained antibodies to whole-cell and recombinant antigens (protein [p]35, p37, o ...201222247369
high seroprevalence of borrelia miyamotoi antibodies in forestry workers and individuals suspected of human granulocytic anaplasmosis in the netherlands.substantial exposure to borrelia miyamotoi occurs through bites from ixodes ricinus ticks in the netherlands, which also transmit borrelia burgdorferi sensu lato and anaplasma phagocytophilum. direct evidence for b. miyamotoi infection in european populations is scarce. a flu-like illness with high fever, resembling human granulocytic anaplasmosis, has been attributed to b. miyamotoi infections in relatively small groups. borrelia miyamotoi infections associated with chronic meningoencephalitis ...201425356364
bill c-442: shining the limelight on the lyme-like? 201425371682
population-based passive tick surveillance and detection of expanding foci of blacklegged ticks ixodes scapularis and the lyme disease agent borrelia burgdorferi in ontario, canada.we identified ticks submitted by the public from 2008 through 2012 in ontario, canada, and tested blacklegged ticks ixodes scapularis for borrelia burgdorferi and anaplasma phagocytophilum. among the 18 species of ticks identified, i. scapularis, dermacentor variabilis, ixodes cookei and amblyomma americanum represented 98.1% of the 14,369 ticks submitted. rates of blacklegged tick submission per 100,000 population were highest in ontario's eastern region; d. variabilis in central west and easte ...201425171252
the prevalence of borrelia miyamotoi infection, and co-infections with other borrelia spp. in ixodes scapularis ticks collected in canada.blacklegged ticks, ixodes scapularis are vectors of the tick-borne pathogens borrelia burgdorferi, anaplasma phagocytophilum and babesia microti. recently, the i. scapularis-borne bacterium borrelia miyamotoi has been linked to human illness in north america. the range of this tick is expanding in canada which may increase the potential for human exposure to these agents.201424731287
genetic diversity of salp15 in the ixodes ricinus complex (acari: ixodidae).salp15, a 15-kda tick salivary gland protein, is both essential for ticks to successfully obtain host blood and also facilitates transmission of lyme borreliosis. to determine whether the salp15 gene is expressed in ixodes persulcatus and ixodes sinensis, principle vectors of lyme borreliosis in china, we studied transcriptions of this gene in semi-engorged larvae, nymph and adults of these two species. a total of eight salp15 homologues, five in i. persulcatus and three in i. sinensis, were ide ...201424714063
serological and molecular prevalence of selected canine vector borne pathogens in blood donor candidates, clinically healthy volunteers, and stray dogs in north carolina.canine vector borne diseases (cvbds) comprise illnesses caused by a spectrum of pathogens that are transmitted by arthropod vectors. some dogs have persistent infections without apparent clinical, hematological or biochemical abnormalities, whereas other dogs develop acute illnesses, persistent subclinical infections, or chronic debilitating diseases. the primary objective of this study was to screen healthy dogs for serological and molecular evidence of regionally important cvbds.201424655461
tick-borne pathogens in northwestern california, usa. 201424565119
an ixodes minor and borrelia carolinensis enzootic cycle involving a critically endangered mojave desert rodent.microtus californicus scirpensis is an endangered, isolated subspecies of california vole. it requires water pools and riparian bulrush (schoenoplectus americanus) and occupies some of the rarest habitat of any north american mammal. the minimally vegetated, extremely arid desert surrounding the pools is essentially uninhabitable for ixodes species ticks. we describe an enzootic cycle of borrelia carolinensis in ixodes minor ticks at a site 3500 km distant from the region in which i. minor is kn ...201425035799
insecticide/acaricide resistance in fleas and ticks infesting dogs and cats.this review defines insecticide/acaricide resistance and describes the history, evolution, types, mechanisms, and detection of resistance as it applies to chemicals currently used against fleas and ticks of dogs and cats and summarizes resistance reported to date. we introduce the concept of refugia as it applies to flea and tick resistance and discuss strategies to minimize the impact and inevitable onset of resistance to newer classes of insecticides. our purpose is to provide the veterinary p ...201424393426
detection of lyme borrelia in questing ixodes scapularis (acari: ixodidae) and small mammals in louisiana.lyme borreliosis is caused by spirochetes from the borrelia burgdorferi sensu lato species complex. in the united states, b. burgdorferi sensu stricto (s.s.; johnson, schmid, hyde, steigerwalt, and brenner) is the most common cause of human lyme borreliosis. with >25,000 cases reported annually, it is the most common vector-borne disease in the united states. although approximately 90% of cases are contained to the northeastern and great lake states, areas in canada and some southern states are ...201424605479
gis and remote sensing use in the exploration of lyme disease epidemiology.given the relatively recent recognition of lyme disease (ld) by cdc in 1990 as a nationally notifiable infectious condition, the rise of reported human cases every year argues for a better understanding of its geographic scope. the aim of this inquiry was to explore research conducted on spatiotemporal patterns of lyme disease in order to identify strategies for implementing vector and reservoir-targeted interventions. the focus of this review is on the use of gis-based methods to study populati ...201526633445
human coinfection with borrelia burgdorferi and babesia microti in the united states.borrelia burgdorferi, the causative agent of lyme disease, and babesia microti, a causative agent of babesiosis, are increasingly implicated in the growing tick-borne disease burden in the northeastern united states. these pathogens are transmitted via the bite of an infected tick vector, ixodes scapularis, which is capable of harboring and inoculating a host with multiple pathogens simultaneously. clinical presentation of the diseases is heterogeneous and ranges from mild flu-like symptoms to n ...201526697208
Displaying items 301 - 400 of 512