infections acquired in the fields and forests of the united states.sportsmen, backpackers, and outdoor workers may present with unusual infections acquired in the fields and forests of the united states. infections to be considered in such persons with a febrile illness include rocky mountain spotted fever, colorado spotted tick fever, babesiosis, borreliosis, and lyme disease. the differential diagnoses for clinical presentations of pulmonary and gastrointestinal disease are also discussed.19846549506
population genetics and phylogenetic analysis of colorado borrelia burgdorferi.borrelia burgdorferi is transmitted in an enzootic cycle in colorado between the tick ixodes spinipalpis and the woodrat neotoma mexicana. the genetic relationship of colorado isolates to other b. burgdorferi isolates is unknown nor have relationships among various colorado isolates been determined. portions of the flagellin (fla), 66-kd protein, and outer surface protein a (ospa) genes were amplified from 71 colorado isolates, screened for genetic variability using single strand conformation po ...199910348251
serologic survey for selected infectious disease agents in swift and kit foxes from the western united states.a serologic survey of swift fox (vulpes velox) and kit fox (v. macrotis) from the western usa was conducted for 12 infectious diseases. samples from swift fox were collected between 1987 and 1992 from colorado (n = 44), kansas (n = 10), and wyoming (n = 9). samples from kit fox were collected in california (n = 86), new mexico (n = 18), utah (n = 9), and arizona (n = 6). overall antibody prevalence rates were 33 of 110 (30%) for canine parvovirus (cpv), 9 of 72 (13%) for canine distemper virus ( ...200011085448
predicting human west nile virus infections with mosquito surveillance data.west nile virus (wnv) has become established across the americas with recent heightened activity causing significant human illness. surveillance methods to predict the risk of human infection are urgently needed to initiate timely preventative measures and justify the expense of implementing costly or unpopular control measures, such as aerial spraying or curfews. we quantified the links between mosquito surveillance data and the spatiotemporal patterns of 3,827 human wnv cases reported over 5 y ...201323825164
elevated lyme disease seroprevalence among dogs in a nonendemic county: harbinger or artifact?lyme disease, a tick-borne illness caused by borrelia burgdorferi, infects humans and other species, including dogs. canine seroprevalence has been suggested as a sentinel marker of human disease risk. a recent publication reported high canine seroprevalence (>5%) in routt county, colorado, an area where lyme disease is generally considered nonendemic. we surveyed veterinarians in routt county and discovered that 11 of 12 seropositive dogs (>90%) had a documented history of travel to or residenc ...201323421882
detection and characterization of borrelia bissettii in rodents from the central california coast.this is the first report of borrelia burgdorferi sensu lato in rodents from san luis obispo county, with most isolates obtained from a previously unreported host, neotoma lepida thomas. b. burgdorferi sensu lato was identified in seven rodent species, including the california vole, microtus californicus peale; dusky-footed woodrat, neotoma fuscipes baird; desert woodrat, neotoma lepida thomas; brush mouse, peromyscus boylii baird; california mouse, peromyscus californicus gambel; deer mouse, per ...200415311469
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 ...200111693872
transmission of the agent of human granulocytic ehrlichiosis by ixodes spinipalpis ticks: evidence of an enzootic cycle of dual infection with borrelia burgdorferi in northern colorado.previous work described an enzootic cycle of borrelia burgdorferi sensu lato (hereafter referred to as b. burgdorferi) maintained by the rodent neotoma mexicana and the tick ixodes spinipalpis in northern colorado. we investigated the incidence of coinfection among rodents with the agent of human granulocytic ehrlichiosis (aohge). aohge was detected in 23.5% of 119 rodent spleens examined. biopsy results indicated that 78 (65.5%) of the 119 rodents were positive for b. burgdorferi, whereas 22 (7 ...200010915099
discovery of an enzootic cycle of borrelia burgdorferi in neotoma mexicana and ixodes spinipalpis from northern colorado, an area where lyme disease is intensive enzootic cycle of borrelia burgdorferi was seen in populations of the mexican wood rat, neotoma mexicana, and ixodes spinipalpis ticks in northern colorado. cultures of rodent ear tissue and ticks yielded 63 spirochetal isolates: 38 n. mexicana, 2 peromyscus difficilis, and 23 i. spinipalpis. all 63 isolates were identified as b. burgdorferi sensu lato by polymerase chain reaction; a representative subset was characterized as b. burgdorferi by sds-page and immunoblotting. a tick-der ...19948077722
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 ...200010921989
culturing selects for specific genotypes of borrelia burgdorferi in an enzootic cycle in colorado, borrelia burgdorferi sensu stricto, the etiologic agent of lyme disease, is maintained in an enzootic cycle between ixodes spinipalpis ticks and neotoma mexicana rats (27). the frequencies of flagellin (fla), 66-kda protein (p66), and outer surface protein a (ospa) alleles were examined in 71 b. burgdorferi isolates from samples from colorado. approximately two-thirds of these samples were isolates from i. spinipalpis ticks that had been cultured in bsk-h medium prior to dna extract ...19979276416
tick-borne illnesses.tick-borne diseases are prevalent throughout the united states. these illnesses are caused by a variety of different pathogens that use ticks as vectors, including bacteria, viruses, rickettsia, and protozoa. some of the most common illnesses caused by ticks are lyme disease, rocky mountain spotted fever, babesiosis, ehrlichiosis, anaplasmosis, tularemia, colorado tick fever, tick-borne relapsing fever, and powassan disease. unique skin changes, fever, and influenza-like symptoms may indicate ti ...201626963018
tick-borne disease.tick-borne diseases in the united states include rocky mountain spotted fever, lyme disease, ehrlichiosis, tularemia, babesiosis, colorado tick fever, and relapsing fever. it is important for family physicians to consider these illnesses when patients present with influenza-like symptoms. a petechial rash initially affecting the palms and soles of the feet is associated with rocky mountain spotted fever, whereas erythema migrans (annular macule with central clearing) is associated with lyme dise ...200515999870
dermatoses from ticks.ticks are ectoparasites that cause dermatologic disease directly by their bite and indirectly as vectors of bacterial, rickettsial, protozoal, and viral diseases. in north america, where ticks are the leading cause of vector-borne infection, dermatologists should recognize several tick species. basic tick biology and identification will be reviewed. tick bites cause a variety of acute and chronic skin lesions. the tick-borne diseases include lyme disease, tick-borne relapsing fever, tularemia, b ...200312963900
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