Publications

the global distribution of lyme disease.	erythema chronicum migrans (ecm), the skin lesion characteristic of lyme disease, was first described in sweden in 1909; subsequently, cases of ecm have been reported from at least 19 countries on three continents. in europe cases have occurred within the range of ixodes ricinus ticks, the recognized vector of ecm in europe, although one case outside this range has been ascribed to mosquito bites. in 1970 the first case of ecm acquired in the united states was reported, and in 1977, the full sym ...	1985	3885366
ixodes pacificus cooley and kohls, 1943: its life-histor and occurrence.		1968	5693986
population genetic structure of ixodes pacificus (acari:ixodidae) using allozymes.	genetic analysis of the population structure of the western blacklegged tick, ixodes pacificus cooley & kohls, was conducted using allozymes. this vector tick transmits the lyme disease spirochete, borrelia burgdorferi johnson, schmid, hyde, steigerwalt & brenner, in the far-western united states. it ranges from british columbia to baja california and disjunct populations are present in oregon, nevada, utah, and arizona. host-seeking adult ticks were collected from vegetation across the range of ...	1997	9220679
reported distribution of ixodes scapularis and ixodes pacificus (acari: ixodidae) in the united states.	lyme disease, caused by infection with borrelia burgdorferi, is the most frequently reported arthropod-borne disease in the united states. to develop a national map of the distribution of the vectors of b. burgdorferi to humans (ixodes scapularis say and ixodes pacificus cooley & kohls ticks), we sent questionnaires to acarologists, health officials, and lyme disease researchers; surveyed the 1966-1996 medline data base; and reviewed 1907-1995 national tick collection data. tick collection metho ...	1998	9775584
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
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
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
spatial patterns of lyme disease risk in california based on disease incidence data and modeling of vector-tick exposure.	ixodes pacificus, particularly the nymphal life stage, is the primary vector to humans of the lyme disease agent borrelia burgdorferi in california. during 2004, we collected i. pacificus nymphs from 78 woodland sites in ecologically diverse mendocino county, which has a moderately high incidence of lyme disease. within this county, nymphal density was elevated in forested areas with a growing degree day range of 2,600-3,000 (10 degrees c base). using a geographic information systems approach, w ...	2006	17038692
differential exposure to anaplasma phagocytophilum in rodent species in northern california.	anaplasma phagocytophilum is a zoonotic tick-borne rickettsial pathogen that causes granulocytic anaplasmosis (ga) in humans, horses, and dogs. in california, dusky-footed woodrats (neotoma fuscipes) are a putative reservoir host, and ixodes pacificus is a vector for transmission from rodents to humans, dogs, and horses. cases are clustered in coastal and sierra nevada foothill regions, but not necessarily in proximity to infected woodrats. this study was designed to compare exposures and active ...	2008	18047398