Publications

dusky-footed wood rats (neotoma fuscipes) as reservoirs of granulocytic ehrlichiae (rickettsiales: ehrlichieae) in northern california.	dusky-footed wood rats (neotoma fuscipes) and peromyscus sp. mice (p. maniculatus and p. truei) were collected from one site in placer county, one site in santa cruz county, and two sites in sonoma county in northern california. serum or plasma samples from 260 rodents were tested for antibodies to the agent of human granulocytic ehrlichiosis. of these, samples from 25 wood rats (34% of those tested) and 10 (8%) peromyscus sp. mice were found to be seropositive, but only those from one site. pcr ...	1999	10488199
molecular typing of borrelia burgdorferi sensu lato: taxonomic, epidemiological, and clinical implications.	borrelia burgdorferi sensu lato, the spirochete that causes human lyme borreliosis (lb), is a genetically and phenotypically divergent species. in the past several years, various molecular approaches have been developed and used to determine the phenotypic and genetic heterogeneity within the lb-related spirochetes and their potential association with distinct clinical syndromes. these methods include serotyping, multilocus enzyme electrophoresis, dna-dna reassociation analysis, rrna gene restri ...	1999	10515907
serodiagnosis of human granulocytic ehrlichiosis by a recombinant hge-44-based enzyme-linked immunosorbent assay.	current antibody testing for human granulocytic ehrlichiosis relies predominantly on indirect fluorescent-antibody assays and immunoblot analysis. shortcomings of these techniques include high cost and variability of test results associated with the use of different strains of antigens derived from either horses or cultured hl-60 cells. we used recombinant protein hge-44, expressed and purified as a maltose-binding protein (mbp) fusion peptide, as an antigen in a polyvalent enzyme-linked immunos ...	1999	10523549
association of ixodes pacificus (acari: ixodidae) with the spatial and temporal distribution of equine granulocytic ehrlichiosis in california.	this study was conducted to determine if the biology of certain ticks associated with horses regulates the spatial and temporal distribution of equine granulocytic ehrlichiosis (ege) in california north of monterey county. we compared the spatial and temporal distribution of ege cases with the seasons of activity and life histories of ticks that infest horses. spatially, cases collected from equine veterinarians clustered around each other in a manner different from the way in which control citi ...	1999	10534948
quantitative evaluation of ehrlichial burden in horses after experimental transmission of human granulocytic ehrlichia agent by intravenous inoculation with infected leukocytes and by infected ticks.	this paper describes the kinetics of the human granulocytic ehrlichiosis agent in the blood of horses experimentally infected by intravenous inoculation with infected leukocytes and by infected ticks as evaluated by using a real-time quantitative pcr assay. the data obtained indicated differences in the period of incubation, duration of rickettsemia, and initial and maximal ehrlichial loads between the two routes of infection.	1999	10565928
granulocytic ehrlichiosis and tick infestation in mountain lions in california.	forty-seven mountain lions (puma concolor) collected year-round in 1996 to 1998 from the sierra nevada foothills, the northern coast ranges, and in monterey county (california, usa) were examined for infestation with ixodes pacificus and dermacentor variabilis ticks. ticks were found predominantly in winter and spring. the seroprevalence of granulocytic ehrlichiae (ge) antibodies (ehrlichia equi or the agent of human granulocytic ehrlichiosis) was 17% and the pcr-prevalence of dna characteristic ...	1999	10574529
variation in the density of questing ixodes pacificus (acari:ixodidae) nymphs infected with borrelia burgdorferi at different spatial scales in california.	the density of, and prevalence of infection with borrelia burgdorferi in, ixodes pacificus nymphs as well as the density of infected nymphs were compared at 12 properties at a small rural community at high risk for lyme disease (chr) and at 12 areas at the university of california hopland research and extension center (hrec), mendocino county, california. the mean infection prevalence and density of infected nymphs were 1.7% (range, 0-4.2%) and 0.10 infected nymphs per 100 m2 (range, 0-0.23 per ...	1999	10577716
abundance of ticks (acari: ixodidae) infesting the western fence lizard, sceloporus occidentalis, in relation to environmental factors.	we examined the impact of environmental characteristics, such as habitat type, topographic exposure and presence of leaf litter, on the abundance of ixodes pacificus ticks infesting the western fence lizard (sceloporus occidentalis) at the university of california hopland research and extension center (hrec), mendocino county, california. a total of 383 adult lizards were slip-noosed and examined for tick infestation in april and may 1998. at least 94% of the lizards were infested by ticks and a ...	1999	10581712
mitochondrial dna sequence variation in ixodes pacificus (acari: ixodidae).	the western black-legged tick, ixodes pacificus, is a primary vector of the spirochaete, borrelia burgdorferi, that causes lyme disease. we used variation in a 355-bp dna portion of the mitochondrial cytochrome oxidase iii gene to assess the population structure of the tick across its range from british columbia to southern california and east to utah. ixodes pacificus showed considerable haplotype diversity despite low nucleotide diversity. maximum parsimony and isolation-by-distance analyses r ...	1999	10583539
anti-arthropod saliva antibodies among residents of a community at high risk for lyme disease in california.	the role of the western black-legged tick (ixodes pacificus) versus that of other potential arthropod vectors in the epidemiology of lyme disease was evaluated by determining the prevalence of anti-arthropod saliva antibodies (aasa) among residents (n = 104) of a community at high-risk (chr). salivary gland extracts prepared from i. pacificus, the pacific coast tick (dermacentor occidentalis), the western cone-nose bug (triatoma protracta), and the western tree-hole mosquito (aedes sierrensis) w ...	1999	10586924
experimental and field evaluations of two acaracides for control of i. pacificus (acari: ixodidae) in northern california.	use of acaricides for the control of ixodes pacificus (cooley & kohls), the vector of lyme borreliosis in the western united states, can be a beneficial component in a program to reduce the morbidity of lyme borreliosis in california. three commercially available acaricides, carbaryl, chlorpyrifos, and diazinon, were evaluated in laboratory bioassays for their effectiveness against i. pacificus adults. based on bioassay results, chlorpyrifos and carbaryl were selected for field evaluations. chlo ...	1999	10593063
cytokine responses of c3h/hen mice infested with ixodes scapularis or ixodes pacificus nymphs.	lyme borreliosis, caused by borrelia burgdorferi, is transmitted by ixodes scapularis in the eastern and midwestern united states and by ixodes pacificus in the far-western united states. studies have shown that infestation with i. scapularis nymphs modulates host cytokine production; however, the influence of i. pacificus infestation on host cytokines remains uninvestigated. this study demonstrated how repeated infestations with pathogen-free i. scapularis or i. pacificus nymphs affects the pro ...	2000	10607289
isolation, cultivation, and characterization of borrelia burgdorferi from rodents and ticks in the charleston area of south carolina.	twenty-eight borrelia burgdorferi isolates from the charleston, s.c., area are described. this represents the first report and characterization of the lyme disease spirochete from that state. the isolates were obtained from december 1994 through december 1995 from the tick ixodes scapularis, collected from vegetation, and from the rodents peromyscus gossypinus (cotton mouse), neotoma floridana (eastern wood rat), and sigmodon hispidus (cotton rat). all isolates were screened immunologically by i ...	2000	10618074
human granulocytic ehrlichiosis agent infection in a pony vaccinated with a borrelia burgdorferi recombinant ospa vaccine and challenged by exposure to naturally infected ticks.	a pony was vaccinated with recombinant ospa vaccine (rospa) and then exposed 3 months later to borrelia burgdorferi-infected ticks (ixodes scapularis) collected in westchester county, n.y. at 2 weeks after tick exposure, the pony developed a high fever (105 degrees f). buffy coat smears showed that 20% of neutrophils contained ehrlichial inclusion bodies (morulae). flunixin meglumine (1 g daily) was given for 2 days, and the body temperature returned to normal. pcr for ehrlichial dna was perform ...	2000	10618280
conservation and heterogeneity of vlse among human and tick isolates of borrelia burgdorferi.	the vls (variable major protein [vmp]-like sequence) locus of borrelia burgdorferi encodes an antigenic variation system that closely resembles the vmp system of relapsing fever borreliae. to determine whether vls sequences are present consistently in low-passage, infectious isolates of b. burgdorferi, 22 blood and erythema migrans biopsy isolates from lyme disease patients in westchester county, new york, were examined by southern blot and pcr analysis. each of the strains contained a single pl ...	2000	10678995
prevalence of lyme disease borrelia spp. in ticks from migratory birds on the japanese mainland.	borrelia sp. prevalence in ticks on migratory birds was surveyed in central japan. in autumn, a total of 1,733 birds representing 40 species were examined for ticks. a total of 361 ticks were obtained from 173 birds of 15 species, and these ticks were immature haemaphysalis flava (94.4%), haemaphysalis longicornis, ixodes columnae, ixodes persulcatus, ixodes turdus, and an unidentified ixodes species. of these, 27 juveniles of h. flava on turdus pallidus, turdus cardis, or emberiza spodocephala, ...	2000	10698761
pcr detection of granulocytic ehrlichiae in ixodes ricinus ticks and wild small mammals in western switzerland.	the presence of granulocytic ehrlichiae was demonstrated by pcr in ixodes ricinus ticks and wild small mammals in switzerland in two areas of endemicity for bovine ehrlichiosis. six ticks (three females and three nymphs) (1.4%) of 417 i. ricinus ticks collected by flagging vegetation contained ehrlichial dna. a total of 201 small mammals from five species, wood mouse (apodemus sylvaticus), yellow-necked mouse (apodemus flavicollis), earth vole (pitymys subterraneus), bank vole (clethrionomys gla ...	2000	10698987
experimental inoculation with human granulocytic ehrlichia agent derived from high- and low-passage cell culture in horses.	we report the successful infection throughout intravenous inoculation with low and high passage of in vitro-grown human granulocytic ehrlichiosis (hge) agent in horses. differences in disease severity but not in incubation time, hematological changes, pcr detection, ehrlichial load, seroconversion time, and titer range were noted between horses infected with a low and a high passage of in vitro-grown hge agent.	2000	10699041
comparison of the nucleotide sequences of 16s rrna, 444 ep-ank, and groesl heat shock operon genes in naturally occurring ehrlichia equi and human granulocytic ehrlichiosis agent isolates from northern california.	we examined 11 naturally occurring isolates of ehrlichia equi in horses and two human granulocytic ehrlichiosis agent isolates in california for sequence diversity in three genes. ehrlichia equi isolates were from sierra (n = 6), mendocino (n = 3), sonoma (n = 1), and marin (n = 1) counties, and human granulocytic ehrlichiosis (hge) agent isolates were obtained from humboldt county. pcr with specific primers for 16s rrna, 444 ep-ank and groesl heat shock operon genes successfully produced amplic ...	2000	10747108
[distribution of cytoplasmically inherited bacteria spiroplasma causing female bias in the eurasian populations of adalia bipunctata].	two-spot ladybirds adalia bipunctata were collected from the populations of western and eastern europe and central asia. the agent killing males at the early embryonic stage in these populations was identified as bacteria of the genus spiroplasma. bacteria found in a. bipunctata proved to be phylogenetically related to spiroplasma ixodetis (typical line y-32) found in tick ixodes pacificus but not to spiroplasma causing the death of male embryos in drosophila.	2000	10752031
ehrlichia equi infection of horses from minnesota and wisconsin: detection of seroconversion and acute disease investigation.	equine granulocytic ehrlichiosis (ege) is caused by infection with ehrlichia equi. ege has been reported primarily in northern california, where e equi is transmitted by the tick ixodes pacificus. reports of ege and the emergence of human granulocytic ehrlichia in minnesota prompted a seroprevalence study of e equi in horses of minnesota and wisconsin. tick (ixodes scapularis) endemic areas of minnesota and wisconsin were compared to nonendemic regions of minnesota. indirect fluorescent antibody ...	2000	10830537
genetic diversity of borrelia burgdorferi sensu lato in ticks from mainland portugal.	to date borrelia lusitaniae is the only genospecies of borrelia burgdorferi sensu lato isolated from ixodes ricinus ticks collected in portugal and tunisia. this suggests that the genospecies diversity of b. burgdorferi sensu lato decreases toward the southwestern margin of its old world subtropical range. in order to further explore the genetic diversity of b. burgdorferi sensu lato from this region, 55 i. ricinus and 27 hyalomma marginatum questing adults, collected during the spring of 1998 f ...	2000	10834965
genetic characteristics of borrelia coriaceae isolates from the soft tick ornithodoros coriaceus (acari: argasidae).	two borrelia isolates (ca434 and ca435) cultured from the soft tick ornithodoros coriaceus were analyzed by contour-clamped homogeneous electric field gel electrophoresis of unrestricted and apai-restricted dna, standard electrophoresis of bamhi- and hindiii-restricted dna, southern hybridization, restriction fragment length polymorphism and sequencing of the 16s rrna gene, and amplification of the 5s-23s intergenic spacer region. these isolates were compared with borrelia coriaceae type strain ...	2000	10878063
identification of ehrlichia chaffeensis by nested pcr in ticks from southern china.	a total of 717 ticks collected from southern china were examined by nested pcr for the presence of ehrlichia chaffeensis. sixteen (55. 2%) of 29 adult amblyomma testudinarium ticks and 28 (11.7%) of 240 adult and at least 4.2% of 215 nymphal (pooled specimens) haemaphysalis yeni ticks tested positive. four other species of ticks were negative. selected positive amplicons were confirmed by dna sequencing.	2000	10878087
clinical manifestations of tick-borne infections in children.		2000	10882645
babesiosis.	babesiosis is an emerging, tick-transmitted, zoonotic disease caused by hematotropic parasites of the genus babesia. babesial parasites (and those of the closely related genus theileria) are some of the most ubiquitous and widespread blood parasites in the world, second only to the trypanosomes, and consequently have considerable worldwide economic, medical, and veterinary impact. the parasites are intraerythrocytic and are commonly called piroplasms due to the pear-shaped forms found within inf ...	2000	10885987
borrelia isolates in northern colorado identified as borrelia bissettii.	previous work described borrelia burgdorferi sensu lato group dn127 as a new genospecies, borrelia bissettii, and prompted the present study to identify the borrelia spp. that exist in northern colorado. to determine the genospecies present, we analyzed two specific intergenic spacer regions located between the 5s and 23s and the 16s and 23s ribosomal genes. phylogenetic analysis of the derived sequences clearly demonstrated that these isolates, originating from rodents captured in the foothills ...	2000	10921989
a state-by-state survey of ticks recorded from humans in the united states.	based on tick specimens accessioned into the u.s. national tick collection, the species of ticks recorded as ectoparasites of humans are documented and compared for 49 u.s. states. a total of 44 tick species was recorded as parasites of humans, consisting of 11 species of soft ticks (argasidae) and 33 species of hard ticks (ixodidae). four of the hard tick species are not native to the u.s. and were removed from travelers returning from foreign destinations. therefore, we record 40 of the 84 spe ...	2000	10925803
density and spatial distribution of ixodes pacificus (acari: ixodidae) in two recreational areas in north coastal california.	the density and distribution of ixodes pacificus was assessed at 2 parks in north coastal california. the density of i. pacificus adults and nymphs varied significantly between years, trails, and sides of trails. adult ticks occurred on vegetation along sun-exposed trails in january through march, their density (0-1.93 per 20 m) correlated with brush density, trail width, and presence of an uphill slope. nymphs (0.06-5.10 per 20 m) occurred in leaf litter along shaded trails in may-july. adult i ...	2000	11037789
granulocytic ehrlichiae in ixodes persulcatus ticks from an area in china where lyme disease is endemic.	a total of 372 adult ixodes persulcatus ticks were collected from vegetation in a forest area of heilongjiang province in northeastern china, where lyme disease is known to be endemic. the ticks were examined for the presence of granulocytic ehrlichiae by heminested pcr with primers derived from the 16s rrna gene. of 310 ticks obtained from the dahe forestry farm, two pools (each containing 5 ticks) were found positive, with a minimum infection rate of 0.6%. ehrlichial dna was also detected in o ...	2000	11060091
interleukin-10 modulates proinflammatory cytokines in the human monocytic cell line thp-1 stimulated with borrelia burgdorferi lipoproteins.	we determined previously that lipoproteins of borrelia burgdorferi stimulate inflammatory and anti-inflammatory cytokines (interleukin-10 [il-10]) in monocytes. il-10 could have an effect on innate and acquired immune responses to b. burgdorferi and influence the magnitude of the infectious inoculum and disease outcome. to understand the mechanism(s) of il-10 action during early infection, when innate immunity expressed chiefly by skin macrophages is key, we investigated the effect of exogenous ...	2000	11083779
ecology of borrelia burgdorferi in ticks (acari: ixodidae), rodents, and birds in the sierra nevada foothills, placer county, california.	this study examined the prevalence of borrelia burgdorferi johnson, schmid, hyde, steigerwalt & brenner in host-seeking adult and nymphal ixodes pacificus cooley & kohls and estimated the i. pacificus infestation and b. burgdorferi infection of rodent and avian hosts in the western sierra nevada foothills of northern california. additionally, we identified species likely to participate in an enzootic cycle for b. burgdorferi in this yellow pine transition habitat. evidence of infection with b. b ...	2000	11126549
complement-mediated killing of borrelia burgdorferi by nonimmune sera from sika deer.	various species of cervid deer are the preferred hosts for adult, black-legged ticks (ixodes scapularis and ixodes pacificus) in the united states. although frequently exposed to the agent of lyme disease (borrelia burgdorferi), these animals, for the most part, are incompetent as transmission reservoirs. we examined the borreliacidal activity of normal and b. burgdorferi-immune sera from sika deer (cervus nippon) maintained in a laboratory setting and compared it to that of similar sera from re ...	2000	11191897
specificities and sensitivities of four monoclonal antibodies for typing of borrelia burgdorferi sensu lato isolates.	borrelia burgdorferi, the agent of lyme borreliosis, is genetically more heterogeneous than previously thought. in europe five genospecies have been described from the original b. burgdorferi sensu lato (sl): b. burgdorferi sensu stricto (ss), b. garinii, b. afzelii, b. lusitaniae, and b. valaisiana. in the united states, b. burgdorferi ss as well as b. bissettii in california and b. andersonii on the east coast were differentiated. in asia, b. japonica has been identified along, with b. garinii ...	2001	11238225
ectoparasites of the island fox on santa cruz island.	the ectoparasite fauna for island foxes (urocyon littoralis) on santa cruz island (california, usa) in april (wet season) and september (dry season) 1998 was evaluated. three taxa of ectoparasites were identified. these were fleas (pulex irritans), lice (neotrichodectes mephitidis), and ticks (ixodes pacificus). ectoparasite abundances varied seasonally. typical of insular endemic species, island foxes may be especially vulnerable to the introduction of novel disease organisms and their vectors.	2001	11272496
molecular evidence of bartonella spp. in questing adult ixodes pacificus ticks in california.	ticks are the vectors of many zoonotic diseases in the united states, including lyme disease, human monocytic and granulocytic ehrlichioses, and rocky mountain spotted fever. most known bartonella species are arthropod borne. therefore, it is important to determine if some bartonella species, which are emerging pathogens, could be carried or transmitted by ticks. in this study, adult ixodes pacificus ticks were collected by flagging vegetation in three sites in santa clara county, calif. pcr-res ...	2001	11283031
description and epidemiology of theileria youngi n. sp. from a northern californian dusky-footed woodrat (neotoma fuscipes) population.	an epidemiologic study designed to identify the small mammal reservoir for the zoonotic wa1-type babesial parasite resulted in the discovery of a small, intraerythrocytic piroplasm in smeared blood from dusky-footed woodrats (neotoma fuscipes) in northern california. the woodrat parasites were isolated and compared to other piroplasm parasites based on their morphology, antigenicity, and genetic characteristics. these studies indicated that the woodrat parasites were not the wa1-type babesial ag ...	2001	11318567
genetic heterogeneity of borrelia burgdorferi sensu lato in the southern united states based on restriction fragment length polymorphism and sequence analysis.	fifty-six strains of borrelia burgdorferi sensu lato, isolated from ticks and vertebrate animals in missouri, south carolina, georgia, florida, and texas, were identified and characterized by pcr-restriction fragment length polymorphism (rflp) analysis of rrf (5s)-rrl (23s) intergenic spacer amplicons. a total of 241 to 258 bp of intergenic spacers between tandemly duplicated rrf (5s) and rrl (23s) was amplified by pcr. msei and drai restriction fragment polymorphisms were used to analyze these ...	2001	11427560
health protocol for translocation of free-ranging elk.	when considering an elk (cervus elaphus) restoration program, wildlife managers must evaluate the positive and negative elements of translocation. we prepared this protocol to give an overview of health considerations associated with translocation of elk, with an emphasis on movement of free-ranging elk from western north america to the southeastern usa. we evaluated infectious agents and ectoparasites reported in elk from two perspectives. first, we made a qualitative estimate of the ability of ...	2001	11504216
molecular typing of the etiologic agent of human granulocytic ehrlichiosis.	the p44 gene of the agent of human granulocytic ehrlichiosis (aohge) encodes a 44-kda major outer surface protein. a technique was developed for the typing of the aohge based on the pcr amplification of the p44 gene followed by a multiple restriction digest with hindiii, ecorv, and aspi to generate restriction fragment length polymorphism patterns. twenty-four samples of the aohge were collected from geographically dispersed sites in the united states and included isolates from humans, equines, ...	2001	11526190
birds and their ticks in northwestern california: minimal contribution to borrelia burgdorferi enzootiology.	birds and their attendant ticks were surveyed for infection with the lyme disease spirochete borrelia burgdorferi, in chaparral and woodland-grass habitats in northwestern california from march to july, 1998 to 1999. in total, 234 birds were captured and recaptured (15%); nearly 2.5 times more birds were captured in chaparral than in woodland-grass. overall, 34 species representing 15 families were collected during this study; of these, 24 species were caught in chaparral, 19 in woodland-grass, ...	2001	11534638
evidence for the contribution of point mutations to vlse variation and for apparent constraints on the net accumulation of sequence changes in vlse during infection with lyme disease spirochetes.	in the lyme disease spirochetes, both the ospe and vlse gene families have been demonstrated to undergo sequence variation during infection. to further investigate the mechanisms associated with the generation of vls variation, single-nucleotide polymorphism and subsequent dna sequence analyses were performed on the vlse gene and its paralog, bbj51, a related gene with a frameshift mutation. these analyses focused on a series of postinfection clonal populations obtained from mice infected with b ...	2001	11566983
aortic valve endocarditis in a dog due to bartonella clarridgeiae.	we report the first documented case of endocarditis associated with bartonella clarridgeiae in any species. b. clarridgeiae was identified as a possible etiological agent of human cat scratch disease. infective vegetative valvular aortic endocarditis was diagnosed in a 2.5-year-old male neutered boxer. historically, the dog had been diagnosed with a systolic murmur at 16 months of age and underwent balloon valvuloplasty for severe valvular aortic stenosis. six months later, the dog was brought t ...	2001	11574571
life cycle of ixodes pacificus (acari: ixodidae): timing of developmental processes under field and laboratory conditions.	the developmental timing of ixodes pacficus cooley & kohls, the primary vector of the lyme disease spirochete and the agent of human granulocytic ehrlichiosis in the far-western united states, was determined under field and laboratory conditions. during their seasonal peaks of abundance, each of the three parasitic stages of l. pacificus, both fed and unfed, was placed inside silk-screen packets. these packets were apportioned between four topographic exposures of two hilltop sites in northweste ...	2001	11580041
spatial distribution of seropositivity to the causative agent of granulocytic ehrlichiosis in dogs in california.	to assess spatial and temporal patterns of seroprevalence among dogs in california to the causative agent of granulocytic ehrlichiosis (ge).	2001	11592326
persistent infection in neotoma fuscipes (muridae: sigmodontinae) with ehrlichia phagocytophila sensu lato.	dusky-footed wood rats (neotoma fuscipes baird) and two species of peromyscus mice (p. maniculatus wagner and p. truei shufeldt) were collected over a 16-month period from three sites in sonoma county, california. blood was collected from 93 wood rats and 177 mice and serum or plasma was tested for seroreactivity with ehrlichia phagocytophila sensu lato (also known as the human granulocytic ehrlichiosis agent). thirty-five (37.6%) wood rats and 15 (8.5%) mice were seropositive. positive neotoma ...	2001	11693866
use of a sentinel host system to study the questing behavior of ixodes spinipalpis and its role in the transmission of borrelia bissettii, human granulocytic ehrlichiosis, and babesia microti.	ixodes spinipalpis maintains borrelia bissettii spirochetes in colorado in a cycle involving wood rats and deer mice. this tick has been described as nidicolous, remaining either attached to its rodent hosts or in the rodent nest. nidicolous ticks pose little risk of pathogen transmission to humans if they do not actively quest for hosts. to investigate the questing potential of i. spinipalpis, sentinel mice were placed in an area where i. spinipalpis had been commonly found on wood rats and dee ...	2001	11693872
differentiation of ehrlichia platys and e. equi infections in dogs by using 16s ribosomal dna-based pcr.	we have encountered a previously unrecognized specificity problem when using the small-subunit ribosomal dna (16s rdna)-based pcr primers recommended for use in the identification of ehrlichia equi in clinical samples. these pcr primers annealed to e. platys 16s rdna in blood samples containing high levels of e. platys organisms. therefore, we designed and tested new pcr primers for the identification of e. equi.	2001	11724889
prevalence and abundance of ixodes pacificus immatures (acari: ixodidae) infesting western fence lizards (sceloporus occidentalis) in northern california: temporal trends and environmental correlates.	the prevalence and abundance of immature ixodes pacificus ticks on western fence lizards (sceloporus occidentalis) were examined in relation to time of year, host attributes (i.e., age, gender, and presence or absence of blood parasites), and 5 environmental characteristics, including topographic exposure and ground cover substrate, over a 2-year period in northern california. lizards were infested with subadult ticks from early march until late july or early august, with peak median numbers of ...	2001	11780813
nymphs of the western black-legged tick (ixodes pacificus) collected from tree trunks in woodland-grass habitat.	nymphs of the western black-legged tick, ixodes pacificus, were found on the trunks of trees during spring and summer in northwestern california. in a woodland-grass habitat, large- and medium-sized (> 130 cm and 80-130 cm in circumference, respectively), moss-covered oak (quercus spp.) trees supported ticks significantly more often than trees without these characteristics. additionally, trees with basal leaf-litter and lacking shade (at time of sampling) were significantly associated with the p ...	2001	11813653
lyme disease and current aspects of immunization.	lyme disease is a tick-borne multisystem disease that affects primarily the skin, nervous system, heart and joints. at least three species of borrelia burgdorferi sensu lato, namely borrelia burgdorferi sensu stricto, borrelia garinii, and borrelia afzelii, can cause the disease. this review will focus mainly on the pathophysiology of lyme arthritis, the long-term outcome of lyme disease, and the recently licensed vaccine against lyme disease.	2002	11879534
pcr detection and serological evidence of granulocytic ehrlichial infection in roe deer (capreolus capreolus) and chamois (rupicapra rupicapra).	the role of wild mammals, such as roe deer (capreolus capreolus) and chamois (rupicapra rupicapra), in the epidemiology of granulocytic ehrlichiae in switzerland was investigated. we tested blood samples for ehrlichia phagocytophila genogroup 16s rrna gene sequences by pcr and for immunoglobulin g antibodies against granulocytic ehrlichiae by indirect fluorescent-antibody assay (ifa). overall means of 60.9% of 133 roe deer serum samples and 28.2% of 39 chamois serum samples were seroreactive by ...	2002	11880411
the effect of two different oxytetracycline treatments in experimental ehrlichia phagocytophila infected lambs.	the effect of 2 different oxytetracycline treatments in acute e. phagocytophila infected lambs was investigated. twenty 5-month-old lambs of the dala and rygja breeds were used. ten lambs were inoculated intravenously with a stabilate of an ovine e. phagocytophila strain. on the third day of fever, 4 lambs were given long-acting oxytetracycline (terramycin prolongatum vet, pfizer) (20 mg/kg) intramuscularly and another 4 lambs were given short-acting oxytetracycline (terramycin vet, pfizer) (10 ...	2001	11887394
persistence of granulocytic ehrlichia infection during wintertime in two sheep flocks in norway.	granulocytic ehrlichia infection in sheep is common in norway in areas with ixodes ricinus. in this study, 2 sheep flocks that had been grazing on i. ricinus infested pastures the previous season, were blood sampled after being housed indoors for nearly 6 months during wintertime. thirty animals from each flock were examined for granulocytic ehrlichia infection in the peripheral blood by blood inoculation studies, stained blood smear evaluation, polymerase chain reaction (pcr) analysis and serol ...	2001	11887395
borrelia burgdorferi population kinetics and selected gene expression at the host-vector interface.	by using real-time quantitative pcr, the population dynamics and gene transcription of borrelia burgdorferi were examined in ticks and skin of mice during acquisition of the infection from mice by ticks and during transmission of the infection from ticks to mice. population dynamics were determined by using a flab dna target. a quantitative analysis of flab, ospa, ospc, dbpa, and arp transcription was also performed. the results revealed that both uninfected larval and nymphal ixodes scapularis ...	2002	12065476
investigation of bartonella infection in ixodid ticks from california.	a total of 1253 ixodid ticks (254 tick pools) collected between the end of 1995 and the spring of 1997 from six california counties (el dorado, los angeles, orange, santa cruz, shasta and sonoma) were examined for the presence of bartonella dna by pcr of the citrate synthase gene. of 1,119 adult ixodes pacificus ticks tested, 26 (11.6%) of 224 pools, each containing five ticks, were positive (minimum percentage of ticks harboring detectable bartonella dna, 2.3%). bartonella pcr-positive ticks we ...	2002	12135237
seasonal activity patterns of ixodes pacificus nymphs in relation to climatic conditions.	in western north america, the tick ixodes pacificus cooley & kohls (acari: ixodidae) is the primary vector to humans and domestic animals of the disease agents causing lyme disease and granulocytic ehrlichiosis. we examined the seasonal activity patterns of i. pacificus nymphs over a 4-year period, including the wet and cold el niño winter/spring of 1998, in a dry oak/madrone woodland, and for one year in a cooler and moister redwood/tanoak woodland in mendocino county, california. linear regres ...	2002	12243224
seasonal correlation of sporadic schizophrenia to ixodes ticks and lyme borreliosis.	background: being born in winter and spring is considered one of the most robust epidemiological risk factors for schizophrenia. the aetiology and exact timing of this birth excess, however, has remained elusive so far. since during phylogeny, borrelia dna has led to multiple germ-line mutations within the cb1 candidate gene for schizophrenia, a meta analysis has been performed of all papers on schizophrenic birth excesses with no less than 3000 cases each. all published numerical data were then ...	2002	12453316
relative importance of lizards and mammals as hosts for ixodid ticks in northern california.	abstract lizards and mammals were trapped and examined for ticks from august 1992 to june 1993 in two habitat types, chaparral and woodland-grass, in northern california. five tick species were collected from mammals (dermacentor occidentalis, haemaphysalis leporispalustris, ixodes pacificus, i. spinipalpis, i. woodi), but only i. pacificus was found on lizards. dermacentor occidentalis, i. pacificus, and i. woodi occurred in both habitats, whereas h. leporispalustris and i. spinipalpis were fou ...	2002	12475082
[histopathological changes in lizard skin (reptilia: lacertidae) in feeding places of ticks of the genus ixodes (acari: ixodidae)].	histopathological changes in a skin of lacerta agilis in the places of attachment and feeding of nymphs of ixodes pacificus and i. ricinus were investigated. the mouthparts of ticks are surrounded by the fibrin cone and collagen capsula formed by their hosts. ticks of these species do not produce the cement. a proliferation stage of skin inflammation is expressed, the large collagen capsula is formed as the result of proliferation. neutrophils and eosinophils predominate in the inflammate cell i ...	2002	12481605
antibiotic susceptibilities of anaplasma (ehrlichia) phagocytophilum strains from various geographic areas in the united states.	we tested the antibiotic susceptibilities of eight strains of anaplasma phagocytophilum (the agent of human granulocytic ehrlichiosis) collected in various geographic areas of the united states, including minnesota, wisconsin, california, and new york. the results are homogeneous and show that doxycycline, rifampin, and levofloxacin are the most active antibiotics against these strains in vitro.	2003	12499227
ehrlichia chaffeensis: a prototypical emerging pathogen.	ehrlichia chaffeensis is an obligately intracellular, tick-transmitted bacterium that is maintained in nature in a cycle involving at least one and perhaps several vertebrate reservoir hosts. the moderate to severe disease caused by e. chaffeensis in humans, first identified in 1986 and reported for more than 1,000 patients through 2000, represents a prototypical "emerging infection." knowledge of the biology and natural history of e. chaffeensis, and of the epidemiology, clinical features, and ...	2003	12525424
geographical and seasonal correlation of multiple sclerosis to sporadic schizophrenia.	background: clusters by season and locality reveal a striking epidemiological overlap between sporadic schizophrenia and multiple sclerosis (ms). as the birth excesses of those individuals who later in life develop schizophrenia mirror the seasonal distribution of ixodid ticks, a meta analysis has been performed between all neuropsychiatric birth excesses including ms and the epidemiology of spirochaetal infectious diseases. results: the prevalence of ms and schizophrenic birth excesses entirely ...	2002	12537588
glycerol-3-phosphate acquisition in spirochetes: distribution and biological activity of glycerophosphodiester phosphodiesterase (glpq) among borrelia species.	relapsing-fever spirochetes achieve high cell densities (>10(8)/ml) in their host's blood, while lyme disease spirochetes do not (<10(5)/ml). this striking contrast in pathogenicity of these two groups of bacteria suggests a fundamental difference in their ability to either exploit or survive in blood. borrelia hermsii, a tick-borne relapsing-fever spirochete, contains orthologs to glpq and glpt, genes that encode glycerophosphodiester phosphodiesterase (glpq) and glycerol-3-phosphate transporte ...	2003	12562805
acarologic risk of exposure to emerging tick-borne bacterial pathogens in a semirural community in northern california.	an acarologic study was conducted in a semirural community in northern california to determine the relative abundance of, and the prevalence of infection with, three emerging bacterial pathogens in the western black-legged tick (ixodes pacificus). these included the agents causing lyme disease (borrelia burgdorferi), human granulocytic ehrlichiosis [ehrlichia phagocytophila (formerly ehrlichia equi)], and human monocytic ehrlichiosis (ehrlichia chaffeensis). the study area in sonoma county consi ...	2001	12653148
real-time pcr for simultaneous detection and quantification of borrelia burgdorferi in field-collected ixodes scapularis ticks from the northeastern united states.	the density of spirochetes in field-collected or experimentally infected ticks is estimated mainly by assays based on microscopy. in this study, a real-time quantitative pcr (qpcr) protocol targeting the borrelia burgdorferi-specific reca gene was adapted for use with a lightcycler for rapid detection and quantification of the lyme disease spirochete, b. burgdorferi, in field-collected ixodes scapularis ticks. the sensitivity of qpcr for detection of b. burgdorferi dna in infected ticks was comp ...	2003	12902243
vector competence of ixodes pacificus and i. spinipalpis (acari: ixodidae), and reservoir competence of the dusky-footed woodrat (neotoma fuscipes) and the deer mouse (peromyscus maniculatus), for borrelia bissettii.	we investigated the experimental vector competence of ixodes pacificus cooley and kohls and ixodes spinipalpis hadwen and nuttall, and the reservoir competence of the dusky-footed woodrat (neotoma fuscipes baird) and the deer mouse (peromyscus maniculatus [wagner]), for borrelia bissettii postic, marti ras, lane, hendson, and baranton. both rodent species are capable reservoirs for b. bissettii; infection rates for i. pacificus or i. spinipalpis nymphs fed as larvae on infected animals ranged fr ...	2003	12943110
an enzootic transmission cycle of lyme borreliosis spirochetes in the southeastern united states.	lyme borreliosis, or lyme disease (ld), is a tick-borne zoonotic infection of biomedical significance, caused by borrelia burgdorferi sensu lato (s.l.) spirochetes and transmitted by ixodes species ticks. it usually circulates among wildlife vertebrate reservoirs and vector ticks but may infect humans, causing multisystem problems. in far western and northern north america, the host reservoirs, tick vectors, and genospecies of borrelia are well known but not so in the southern u.s., where there ...	2003	14500917
isolation of bartonella washoensis from a dog with mitral valve endocarditis.	we report the first documented case of bartonella washoensis bacteremia in a dog with mitral valve endocarditis. b. washoensis was isolated in 1995 from a human patient with cardiac disease. the main reservoir species appears to be ground squirrels (spermophilus beecheyi) in the western united states. based on echocardiographic findings, a diagnosis of infective vegetative valvular mitral endocarditis was made in a spayed 12-year-old female doberman pinscher. a year prior to presentation, the re ...	2003	14605197
detection of borrelia burgdorferi, ehrlichia chaffeensis, and anaplasma phagocytophilum in ticks (acari: ixodidae) from a coastal region of california.	a study was conducted in santa cruz county to estimate the prevalence and distribution of the agents of lyme disease, human granulocytic (hge), and human monocytic (hme) ehrlichiosis in 1,187 adult ixodid ticks collected from eight public-use recreation areas over a 2-yr period. borrelia burgdorferi, the causative agent of lyme disease, was detected by a polymerase chain reaction (pcr) in 44 of 776 (5.67%) ixodes pacificus ticks and in 3 of 58 (5.17%) dermacentor variabilis ticks. anaplasma phag ...	2003	14680123
power evaluation of disease clustering tests.	background: many different test statistics have been proposed to test for spatial clustering. some of these statistics have been widely used in various applications. in this paper, we use an existing collection of 1,220,000 simulated benchmark data, generated under 51 different clustering models, to compare the statistical power of several disease clustering tests. these tests are besag-newell's r, cuzick-edwards' k-nearest neighbors (k-nn), the spatial scan statistic, tango's maximized excess e ...	2003	14687424
the western black-legged tick, ixodes pacificus, in the sutter buttes.	the western black-legged tick, ixodes pacificus, was collected from huff canyon in the sutter buttes in north central california, sutter county. the sutter buttes are within the sacramento valley and outside the normal distribution of i. pacificus in california. adult i. pacificus were collected via flagging as they quested along deer trails; subadult life stages were collected from three species of lizard, elgaria multicarinata, sceloporus occidentalis, and s. graciosus. adult ticks were tested ...	2003	14714665
prevalence of bartonella henselae in italian stray cats: evaluation of serology to assess the risk of transmission of bartonella to humans.	bartonella henselae is the major etiological agent of cat scratch disease in humans. cats act as the natural reservoir of b. henselae and can transmit the infection to humans by a bite or scratch. the prevalence of b. henselae in cat populations was evaluated by serological and bacteriological tests. a total of 769 stray cats from three urban and three rural areas in northern italy were sampled between january 1999 and december 2000. the positive and the negative predictive values of serological ...	2004	14715763
sequence analysis of p44 homologs expressed by anaplasma phagocytophilum in infected ticks feeding on naive hosts and in mice infected by tick attachment.	the 44-kda immunodominant outer membrane proteins (p44 proteins) of anaplasma phagocytophilum are encoded by the p44 polymorphic multigene family. the present study examined p44 expression and analyzed the cdna sequences of various p44 transcripts from the spleens and blood of mice infected by the bites of ticks infected with the a. phagocytophilum ntn-1 strain or of naturally infected nymphal ticks and in the salivary glands and midgut tissues of these ticks. a total of 300 p44 cdnas were subje ...	2004	14742506
evaluation of groel gene analysis for identification of borrelia burgdorferi sensu lato.	the nucleotide sequences of the groel genes, the flagellin genes, and the 16s rrna genes from 22 reference strains of borrelia were compared. groel sequence analysis is useful not only in interspecies differentiation but also in intraspecies differentiation of borrelia afzelii and borrelia garinii isolates.	2004	15004091
acarologic risk of exposure to borrelia burgdorferi spirochaetes: long-term evaluations in north-western california, with implications for lyme borreliosis risk-assessment models.	over a 5-year period (1997-2001) the population densities of ixodes pacificus cooley & kohls (acari: ixodidae) nymphs infected with spirochaetes of borrelia burgdorferi sensu lato (s.l.) were evaluated in areas of 2000 ha at two localities (chr, nine sites; hrec, seven sites) 25 km apart in mendocino county, north-western california. the 5-year median density of infected nymphs was significantly higher at chr than at hrec (0.51 vs. 0.09 per 100 m(2) and site-specific yearly densities exceeding o ...	2004	15009444
human behaviors elevating exposure to ixodes pacificus (acari: ixodidae) nymphs and their associated bacterial zoonotic agents in a hardwood forest.	epidemiological evidence suggests that the nymph of the western black-legged tick, ixodes pacificus cooley and kohls, is the primary vector of the lyme disease spirochete, borrelia burgdorferi johnson, schmid, hyde, steigerwalt, and brenner, to humans in northwestern california. in spring 2002, six different human behaviors were evaluated as potential risk factors for acquiring i. pacificus nymphs in a deciduous woodland in mendocino county, california. also, the prevalence of b. burgdorferi sen ...	2004	15061284
[peritrophic matrix in the midgut of tick females of the genus ixodes (acari: ixodidae)].	the formation of the peritrophic matrix in the midgut of females of 5 ixodid tick species (ixodes pacificus, i. pavlovskyi, i. persulcatus, i. ricinus and i. scapularis) was studied by means of light and electron microscopy in different periods of the feeding and after detachment. the formation of the peritrophic matrix started when the first food portions came into the gut lumen, 9-12 hours after the attachment. renovation of the peritrophic matrix took place during the whole feeding period; ev ...	2004	15069874
the emergence of lyme disease.	since its identification nearly 30 years ago, lyme disease has continued to spread, and there have been increasing numbers of cases in the northeastern and north central us. the lyme disease agent, borrelia burgdorferi, causes infection by migration through tissues, adhesion to host cells, and evasion of immune clearance. both innate and adaptive immune responses, especially macrophage- and antibody-mediated killing, are required for optimal control of the infection and spirochetal eradication. ...	2004	15085185
prevalence of borrelia burgdorferi, bartonella spp., babesia microti, and anaplasma phagocytophila in ixodes scapularis ticks collected in northern new jersey.	pcr analysis of ixodes scapularis ticks collected in new jersey identified infections with borrelia burgdorferi (33.6%), babesia microti (8.4%), anaplasma phagocytophila (1.9%), and bartonella spp. (34.5%). the i. scapularis tick is a potential pathogen vector that can cause coinfection and contribute to the variety of clinical responses noted in some tick-borne disease patients.	2004	15184475
life stage-related differences in density of questing ticks and infection with borrelia burgdorferi sensu lato within a single cohort of ixodes pacificus (acari: ixodidae).	the primary aims of this study were to quantify the density of ixodes pacificus cooley and kohls nymphs and adults of the same generational cohort collected within a single year in six oak or madrone leaf litter habitats and to compare the prevalence of infection with borrelia burgdorferi sensu lato (s.l.) in adults originating from nymphal cohorts with a low (<1%) versus high (>10%) infection prevalence. because adult densities were very low both in and adjacent to several sites, direct compari ...	2004	15311473
comparison of disseminated and nondisseminated strains of borrelia burgdorferi sensu stricto in mice naturally infected by tick bite.	clinical isolates of borrelia burgdorferi sensu stricto have been categorized into disseminated and nondisseminated groups based on distinct ribosomal spacer restriction fragment length polymorphism genotypes (rsts). in order to determine whether transmission by tick bite would alter the dissemination dynamics and disease produced by distinct genotypes, disseminated isolates (rst1), nondisseminated isolates (rst3), and a standard laboratory strain (b-31) were established in a murine cycle utiliz ...	2004	15322021
habitat-related variation in infestation of lizards and rodents with ixodes ticks in dense woodlands in mendocino county, california.	during the spring and early summer of 2002, we examined the relative importance of borrelia-refractory lizards (sceloporus occidentalis, elgaria spp.) versus potential borrelia burgdorferi sensu lato (s.l.)-reservoirs (rodents) as hosts for ixodes pacificus immatures in 14 woodland areas (six oak, five mixed oak/douglas fir, and three redwood/tanoak areas) distributed throughout mendocino county, california. lizards were estimated to serve as hosts for 93-98% of all larvae and > or =99.6% of all ...	2004	15347025
a comparison of serologic tests for the detection of serum antibodies to whole-cell and recombinant borrelia burgdorferi antigens in cattle.	serum samples from healthy dairy and beef cattle, living in tick-infested areas of connecticut, usa, were analyzed by polyvalent enzyme-linked immunosorbent assays (elisa), indirect fluorescent antibody (ifa) staining methods, or western blot procedures to detect antibodies to tick-borne agents. of the 80 sera tested by elisa with whole-cell or 10 separate recombinant antigens (fusion proteins) of borrelia burgdorferi sensu stricto, 57 (71%) were positive to 1 or more antigens, while 36 (45%) re ...	2004	15368740
efficiency of drag sampling for estimating population sizes of ixodes pacificus (acari: ixodidae) nymphs in leaf litter.	drag sampling is a commonly used method to obtain relative estimates of the density of questing nymphal ixodes scapularis say and i pacificus cooley & kohls ticks, which are primary vectors of lyme disease spirochetes to humans in north america. however, the efficiency of drag sampling in determining absolute population densities of questing nymphs has not been evaluated previously. therefore, we assessed the efficiency of a single drag-sampling occasion to estimate the total population size of ...	2000	15535598
remote sensing (normalized difference vegetation index) classification of risk versus minimal risk habitats for human exposure to ixodes pacificus (acari: ixodidae) nymphs in mendocino county, california.	in california, ixodes pacificus cooley & kohls nymphs have been implicated as the primary bridging vectors to humans of the spirochetal bacterium causing lyme disease (borrelia burgdorferi). because the nymphs typically do not ascend emergent vegetation, risk of human exposure is minimal in grasslands, chaparral, and woodland-grass. instead, woodlands with a ground cover dominated by leaf litter (hereinafter referred to as woodland-leaf) have emerged as a primary risk habitat for exposure to b. ...	2005	15691012
genetic variants of anaplasma phagocytophilum infecting dogs in western washington state.	eight dogs from western washington state suspected of being infected with anaplasma phagocytophilum because of the finding of morulae in peripheral blood neutrophils were studied for determination of the etiologic agent of disease. all cases were diagnosed between april 2003 and april 2004. six of the eight dogs had no travel history during the 6 months prior to presentation. two dogs had traveled within the northwest united states and canada. fever, lethargy, and anorexia were the most common c ...	2005	15695682
the roles of birds, lizards, and rodents as hosts for the western black-legged tick ixodes pacificus.	we compared the infestation by ixodid ticks of lizards, rodents, and birds collected simultaneously within areas representing common habitat types in mendocino county, ca. lizards were infested only by ixodes pacificus cooley and kohls, birds by i. pacificus and haemaphysalis leporispalustris (packard), and rodents by i. pacificus, i. spinipalpis hadwen and nuttall, i. woodi bishopp, dermacentor occidentalis marx, and d. variabilis (say). infestation by i. pacificus larvae and nymphs of lizards ...	2004	15709249
columbian black-tailed deer (odocoileus hemionus columbianus) as hosts for borrelia spp. in northern california.	the prevalence of infection of columbian black-tailed deer (odocoileus hemionus columbianus) with borrelia spp. was evaluated in an area of northwestern california (usa) where lyme disease is endemic and the relapsing-fever group spirochete borrelia coriaceae is enzootic, and in a far-removed comparison area having a disparate climate and lower density of vector ticks. blood samples collected from both deer herds in 1987, 1988, and from 2000-02 were assayed for borrelial infection with microscop ...	2005	15827217
gis-facilitated spatial epidemiology of tick-borne diseases in coyotes (canis latrans) in northern and coastal california.	ixodes pacificus is the main tick vector for transmission of anaplasma phagocytophilum and borrelia burgdorferi to large vertebrates in california. the present study was undertaken in i. pacificus-infested counties in california to examine spatial and temporal relationships among a. phagocytophilum and b. burgdorferi-exposed coyotes with vegetation type and climate. the overall a. phagocytophilum and b. burgdorferi seroprevalences were 39.5% (n=215) and 18.9% (n=148), respectively, with no assoc ...	2005	15857659
molecular identification and analysis of borrelia burgdorferi sensu lato in lizards in the southeastern united states.	lyme borreliosis (lb) group spirochetes, collectively known as borrelia burgdorferi sensu lato, are distributed worldwide. wild rodents are acknowledged as the most important reservoir hosts. ixodes scapularis is the primary vector of b. burgdorferi sensu lato in the eastern united states, and in the southeastern united states, the larvae and nymphs mostly parasitize certain species of lizards. the primary aim of the present study was to determine whether wild lizards in the southeastern united ...	2005	15870353
immunoglobulin-regulated expression of borrelia burgdorferi outer surface protein a in vivo.	borrelia burgdorferi, the agent of lyme disease, down-regulates outer surface protein a (ospa), which is abundantly expressed in ticks, during infection of the mammalian host. in this study we examined the signals that may be responsible for maintaining the ospa-negative state of spirochetes during infection. transcription of ospa mrna was found in tissues of c3h-severe combined immunodeficient (c3h-scid) mice, but not immunocompetent c3h mice, inoculated with cultured b. burgdorferi, tick-borne ...	2005	15908357
birds, migration and emerging zoonoses: west nile virus, lyme disease, influenza a and enteropathogens.	wild birds are important to public health because they carry emerging zoonotic pathogens, either as a reservoir host or by dispersing infected arthropod vectors. in addition, bird migration provides a mechanism for the establishment of new endemic foci of disease at great distances from where an infection was acquired. birds are central to the epidemiology of west nile virus (wnv) because they are the main amplifying host of the virus in nature. the initial spread of wnv in the u.s. along the ea ...	2003	15931279
western gray squirrel (rodentia: sciuridae): a primary reservoir host of borrelia burgdorferi in californian oak woodlands?	in california, dense woodlands have been recognized as important biotopes where humans are exposed to the nymphal stage of the western blacklegged tick, ixodes pacificus cooley & kohls, the primary vector of the lyme disease spirochete borrelia burgdorferi sensu stricto (s.s.), in the far-western united states. to identify the principal reservoir host(s) of this spirochete, and of closely related spirochetes in the b. burgdorferi sensu lato (s.l.) complex, in dense woodlands in mendocino county, ...	2005	15962792
clinical, epidemiologic, and environmental surveillance for ehrlichiosis and anaplasmosis in an endemic area of northern california.	two forms of tick-borne leukocytotropic rickettsioses have been recognized in california since the mid-1990s: human monocytic ehrlichiosis (hme) caused by ehrlichia chaffeensis and human granulocytic anaplasmosis (hga) caused by anaplasma phagocytophilum. between 1997 and 1999, two cases of hme and four cases of hga were diagnosed in residents of southern humboldt county, california. environmental followup at case-patients' residences revealed dense populations of ixodes pacificus ticks, particu ...	2005	16007950
the transcriptome of the salivary glands of the female western black-legged tick ixodes pacificus (acari: ixodidae).	sequencing of an ixodes pacificus salivary gland cdna library yielded 1068 sequences with an average undetermined nucleotide of 1.9% and an average length of 487 base pairs. assembly of the expressed sequence tags yielded 557 contigs, 138 of which appear to code for secreted peptides or proteins based on translation of a putative signal peptide. based on the blastx similarity of these contigs to 66 matches of ixodes scapularis peptide sequences, only 58% sequence identity was found, indicating a ...	2005	16102420
equine and canine anaplasma phagocytophilum strains isolated on the island of sardinia (italy) are phylogenetically related to pathogenic strains from the united states.	the presence of anaplasma phagocytophilum, a tick-transmitted zoonotic pathogen, was investigated in sardinia using a molecular approach. phylogenetic analysis revealed that sardinian strains are genetically distinct from the two lineages previously described in europe and are closely related to strains isolated in different areas of the united states.	2005	16204571
tick-borne rickettsioses around the world: emerging diseases challenging old concepts.	during most of the 20th century, the epidemiology of tick-borne rickettsioses could be summarized as the occurrence of a single pathogenic rickettsia on each continent. an element of this paradigm suggested that the many other characterized and noncharacterized rickettsiae isolated from ticks were not pathogenic to humans. in this context, it was considered that relatively few tick-borne rickettsiae caused human disease. this concept was modified extensively from 1984 through 2005 by the identif ...	2005	16223955
anaplasma phagocytophilum infection (granulocytic anaplasmosis) in a dog from vancouver island.	a 7-year-old labrador retriever had nonspecific clinical signs that included lethargy, malaise, and difficult ambulation. the dog was native to vancouver island, british columbia, and had never left this area. morulae were identified in polymorphonuclear cells. serologic studies and polymerase chain reaction (pcr) testing confirmed canine anaplasmosis caused by anaplasma phagocytophilum. the dog recovered after treatment with tetracycline.	2005	16231653
novel genetic variants of anaplasma phagocytophilum, anaplasma bovis, anaplasma centrale, and a novel ehrlichia sp. in wild deer and ticks on two major islands in japan.	wild deer are one of the important natural reservoir hosts of several species of ehrlichia and anaplasma that cause human ehrlichiosis or anaplasmosis in the united states and europe. the primary aim of the present study was to determine whether and what species of ehrlichia and anaplasma naturally infect deer in japan. blood samples obtained from wild deer on two major japanese islands, hokkaido and honshu, were tested for the presence of ehrlichia and anaplasma by pcr assays and sequencing of ...	2006	16461655