Publications

nonpathogenic rickettsias related to the spotted fever group isolated from ticks, dermacentor variabilis and dermacentor andersoni from eastern montana.		1963	14053295
collection of dermacentor andersoni (stiles) with carbon dioxide and its application in studies of colorado tick fever virus.		1965	5841585
natural history of tick-borne spotted fever in the usa. susceptibility of small mammals to virulent rickettsia rickettsii.	in the ecology of spotted fever rickettsiae, one of the as yet unsolved problems concerns the significance of small animals in the distribution of rickettsia rickettsii in nature. in the bitter root valley of western montana, a great variety of rodents, rabbits and hares are known to serve as the preferred hosts for the immature stages of the vector tick, dermacentor andersoni.the authors analyse the susceptibility of various species of small mammals to virulent r. rickettsii and evaluate their ...	1966	5296999
spotted fever group rickettsiae in dermacentor variabilis from cape cod, massachusetts.	spotted fever group (sfg) rickettsiae were identified by indirect immunofluorescent antibody tests in 1.1% of 6,956 specimens of dermacentor variabilis collected on cape cod, massachusetts. forty-one of 45 rickettsial isolates were serotyped as rickettsia montana, one as rickettsia rickettsii, and three were unidentified. studies of canines and humans with clinical evidence of spotted fever, and of healthy dogs with antibody to sfg rickettsiae, indicated that exposure of the canine population to ...	1980	6773430
rocky mountain spotted fever in clermont county, ohio. ii. distribution of population and infected ticks in an endemic area.	the epidemiology of rocky mountain spotted fever (rmsf) in relation to the distribution of the human population and infected ticks has not been defined. a study was undertaken in clermont county, ohio, to describe the distribution of population in a highly endemic focus of rmsf and to determine the prevalence of ticks infected with rickettsiae of the spotted fever group. this area was compared to another area of similar size in the same county where the incidence of rmsf was much lower. the popu ...	1980	7352458
endemicity of spotted fever group rickettsiae in connecticut.	to compare rickettsial infectivity and seropositivity rates against spotted fever group (sfg) rickettsiae, ticks and wild mammals were collected from three areas where rickettsia rickettsii was thought to be enzootic in connecticut during 1978-1979, and from four additional sites (with no reported human cases) between 1976 and 1979. of the 1,001 dermacentor variabilis examined by the hemolymph test, 59 (5.9%) contained rickettsia-like organisms; direct immunofluorescence tests verified the prese ...	1981	6789690
serotypes of spotted fever group rickettsiae isolated from dermacentor andersoni (stiles) ticks in western montana.	adult dermacentor andersoni ticks were collected by flagging vegetation in 18 canyons bordering the bitterroot valley, montana, an area where nearly 400 cases of rocky mountain spotted fever (rmsf) have occurred since 1900. three hundred and nine (8.3%) of the 3,705 ticks collected contained hemocyte-associated rickettsia-like organisms of three morphologic types, coccobacillary, fine bacillary, and coarse bacillary (long forms). only the coccobacillary and fine bacillary organisms stained with ...	1981	6782899
antibodies to spotted fever-group rickettsiae in dogs and prevalence of infected ticks in southern connecticut.	blood samples and ticks were obtained from dogs to assess canine exposure to spotted fever-group (sfg) rickettsiae during 1978-1980 in southern connecticut. of the 1,576 dog sera screened by microimmunofluorescence. 174 (11.0%) contained specific antibodies at titers greater than or equal to 1:64 against rickettsia montana (n = 34), r rickettsii (n = 31), r rhipicephali (n = 19), or the unclassified 369-c rickettsia (n = 90). end points greater than or equal to 1:8,192 to r rickettsii and to r r ...	1982	6803626
clinically mild tularemia associated with tick-borne francisella tularensis.	between may 9 and july 3, 1979, 12 cases of glandular or ulceroglandular tularemia occurred in residents of the crow indian reservation in southcentral montana; only 13 cases had been reported from this geographic area in the preceding 25 years. the illness was mild, characterized by fever and cervical or occipital adenopathy. systemic symptoms were self-limited although residual lymphadenopathy was common. francisella tularensis was isolated from ticks (dermacentor variabilis), the suspected ve ...	1983	6886487
epidemiology of rocky mountain spotted fever in ohio, 1981: serologic evaluation of canines and rickettsial isolation from ticks associated with human case exposure sites.	a survey for the prevalence of rocky mountain spotted fever (rmsf) antibodies in dogs associated with confirmed human cases in ohio was conducted during 1981. twelve of 14 confirmed cases (85%) had a history of dog association prior to onset of rmsf. a total of 29 dogs were included in the study, with 16 dogs providing serum samples for antibody testing and the remainder providing tick samples. serum samples tested by indirect microimmunofluorescence techniques revealed 12/16 dogs (75%) to be se ...	1984	6435461
rickettsia rickettsii and rickettsia montana from ixodid ticks in connecticut.	dermacentor variabilis, infected with spotted fever group rickettsiae, parasitized 8 of 70 raccoons captured in newtown, connecticut. the spotted fever agent, rickettsia rickettsii, was isolated and identified from 4 adult d. variabilis and from 1 nymphal ixodes texanus removed from raccoons. this verifies the presence of this etiologic agent in ticks in an area where 6 people had clinical signs and symptoms of rocky mountain spotted fever (rmsf) and antibodies to r. rickettsii. these are the fi ...	1986	3946737
the distribution and dynamics of rickettsia in the tick population of ohio.	a five-year survey of ticks and associated rickettsia in ohio shows a partitioning of spotted fever group rickettsia (namely, rickettsia montana and r. rickettsii) into three areas of the state where the majority of human spotted fever cases occur. the percentage of ticks infected, even in areas with a high incidence of disease, is remarkably low, less than 1%. the statewide infection rate for r. bellii approaches 3%, and this organism appears to be more evenly distributed throughout the state. ...	1990	2378449
dna typing of rickettsiae in naturally infected ticks using a polymerase chain reaction/restriction fragment length polymorphism system.	we used the polymerase chain reaction/restriction fragment length polymorphism (pcr/rflp) rickettsial typing system of regnery and others to rapidly identify rickettsiae in naturally infected ticks. unlike previously described methods, our pcr assays type rickettsiae directly from tick tissues without first isolating the organisms. we collected 226 adult dermacentor andersoni ticks in the bitterroot mountains of western montana and analyzed them for possible rickettsial infection by hemolymph te ...	1994	7906924
rickettsia peacockii sp. nov., a new species infecting wood ticks, dermacentor andersoni, in western montana.	rickettsia peacockii, a new species of spotted fever group rickettsiae, was identified from rocky mountain wood ticks (dermacentor andersoni) collected in the sapphire mountain range on the eastern side of bitterroot valley, montana. dna from r. peacockii skalkahot (t = type strain) in naturally infected tick tissue was amplified by a pcr assay with primer sets derived from eubacterial 16s ribosomal dna (rdna), rickettsial citrate synthase, and 190-kda surface antigen (rompa) genes. partial 16s ...	1997	9103635
prevalence of infection in ticks submitted to the human tick test kit program of the u.s. army center for health promotion and preventive medicine.	in 1997, ticks removed from humans and received alive by the tick-borne disease laboratory of the u.s. army center for health promotion and preventive medicine (usachppm) were tested for pathogens by polymerase chain reaction (pcr). thirty-three of 222 (15%) amblyomma americanum (l.) dnas produced amplicons of the expected size of ehrlichia chaffeensis anderson, dawson & wilson and 26/222 (12%) produced amplicons indicating borrelia burgdorferi johnson, schmid, hyde, steigalt & brenner. five (2% ...	2001	11268694
tick paralysis presenting in an urban environment.	we report the case of a 17-month-old female with tick paralysis presenting to an urban los angeles emergency department. the tick was later identified as the north american wood tick, dermacentor andersoni, and was likely obtained while the family was vacationing on a dude ranch in montana. we discuss the epidemiology of tick paralysis, a differential diagnosis for health care providers, and methods of detection and removal. given the increasing popularity of outdoor activities and ease of trave ...	2004	14984905
sequence and expression analysis of the ompa gene of rickettsia peacockii, an endosymbiont of the rocky mountain wood tick, dermacentor andersoni.	the transmission dynamics of rocky mountain spotted fever in montana appears to be regulated by rickettsia peacockii, a tick symbiotic rickettsia that interferes with transmission of virulent rickettsia rickettsii. to elucidate the molecular relationships between the two rickettsiae and glean information on how to possibly exploit this interference phenomenon, we studied a major rickettsial outer membrane protein gene, ompa, presumed to be involved in infection and pathogenesis of spotted fever ...	2004	15528527
characterization of genetic diversity in dermacentor andersoni (acari: ixodidae) with body size and weight polymorphism.	morphological and discrete genetic differences are found between geographically isolated, allopatric, tick populations. however, we have found differences in sympatric tick populations. notable differences were found in the body size and weight of dermacentor andersoni collected from a single location in montana, usa. these ticks were separated in groups consisting of big (b) and small (s) individuals. the objectives of this study were: (a) to characterize genetic diversity in b and s d. anderso ...	2004	15639135
molecular typing of novel rickettsia rickettsii isolates from arizona.	seven isolates of rickettsia rickettsii were obtained from a skin biopsy, two whole-blood specimens, and from rhipicephalus sanguineus ticks from eastern arizona. molecular typing of seven isolates of r. rickettsii and dna samples from two other rh. sanguineus ticks infected with r. rickettsii was conducted by pcr and dna sequencing of rompa and 12 variable-number tandem repeat regions (vntrs). all dna specimens from arizona were identical to each other and to reference human and dermacentor and ...	2006	17114781
distribution, seasonality, and hosts of the rocky mountain wood tick in the united states.	anaplasma marginale theiler is a tick-borne pathogen that causes anaplasmosis in cattle. there are approximately 20 tick species worldwide that are implicated as vectors of this pathogen. in the united states, dermacentor andersoni stiles and dermacentor variabilis (say) are the principal vectors. the risk of transmission of anaplasmosis to cattle has been largely based on the distribution of d. andersoni in the united states. we developed a centralized geographic database that incorporates coll ...	2006	16506443
absence of rickettsia rickettsii and occurrence of other spotted fever group rickettsiae in ticks from tennessee.	rocky mountain spotted fever (rmsf) is the most common tick-borne illness in tennessee. little is known about the occurrence of r. rickettsii, the causative agent, in ticks in tennessee. to better understand the prevalence and distribution of rickettsial agents in ticks, we tested 1,265 amblyomma, dermacentor, and ixodes adult and nymphal ticks. additionally, we tested 231 amblyomma americanum larvae. ticks were collected from 49 counties from humans, wild animals, domestic canines, and flannel ...	2010	20810834
epidemiology of colorado tick fever in montana, utah, and wyoming, 1995-2003.	colorado tick fever (ctf) is a biphasic, febrile illness caused by a coltivirus and transmitted by the rocky mountain wood tick, dermacentor andersoni, in the western united states and canada. symptoms generally include acute onset of fever, headache, chills, and myalgias; illness often lasts for 3 weeks or more. laboratory-confirmed cases of ctf were identified from public health department records in montana, utah, and wyoming, and from the centers for disease control and prevention diagnostic ...	2010	19725767