Association of Ixodes pacificus (Acari

Ixodidae) with the spatial and temporal distribution of equine granulocytic ehrlichiosis in California

Larisa K. Vredevoe, Phillip J. Richter, John E Madigan, Robert B. Kimsey

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

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 cities of practice were distributed, with foci limited to the Sierra Nevada and coastal foothills. Cases also clustered seasonally; most were diagnosed between November and April. The spatial and temporal pattern of EGE cases closely parallels the well-characterized life history and distribution of Ixodes pacificus Cooley & Kohls, but not other ticks commonly associated with horses. Building on previous studies, there is compelling evidence that this tick has the vectorial capacity to transmit Ehrlichia equi to horses. Based on the life history and distribution of I. pacificus in relation to EGE cases, we reason that this tick is the only biologically plausible vector of E. equi in California, and provide evidence for a tightly linked association between I. pacificus and the epidemiology of EGE.

Original languageEnglish (US)
Pages (from-to)551-561
Number of pages11
JournalJournal of Medical Entomology
Volume36
Issue number5
StatePublished - Sep 1999

Fingerprint

granulocytic ehrlichiosis
Ixodes pacificus
Ehrlichiosis
Ixodidae
Ixodes
Horses
Acari
horses
Ticks
ticks
Anaplasma phagocytophilum
life history
vectorial capacity
Veterinarians
veterinarians
epidemiology
Epidemiology

Keywords

  • Ehrlichia
  • Ehrlichia equi
  • Equine ehrlichiosis
  • Ixodes pacificus
  • Tick
  • Vectorial capacity

ASJC Scopus subject areas

  • Insect Science
  • veterinary(all)

Cite this

Association of Ixodes pacificus (Acari : Ixodidae) with the spatial and temporal distribution of equine granulocytic ehrlichiosis in California. / Vredevoe, Larisa K.; Richter, Phillip J.; Madigan, John E; Kimsey, Robert B.

In: Journal of Medical Entomology, Vol. 36, No. 5, 09.1999, p. 551-561.

Research output: Contribution to journalArticle

@article{c7f7193197bd443d8e1164556aeb13ac,
title = "Association of Ixodes pacificus (Acari: Ixodidae) with the spatial and temporal distribution of equine granulocytic ehrlichiosis in California",
abstract = "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 cities of practice were distributed, with foci limited to the Sierra Nevada and coastal foothills. Cases also clustered seasonally; most were diagnosed between November and April. The spatial and temporal pattern of EGE cases closely parallels the well-characterized life history and distribution of Ixodes pacificus Cooley & Kohls, but not other ticks commonly associated with horses. Building on previous studies, there is compelling evidence that this tick has the vectorial capacity to transmit Ehrlichia equi to horses. Based on the life history and distribution of I. pacificus in relation to EGE cases, we reason that this tick is the only biologically plausible vector of E. equi in California, and provide evidence for a tightly linked association between I. pacificus and the epidemiology of EGE.",
keywords = "Ehrlichia, Ehrlichia equi, Equine ehrlichiosis, Ixodes pacificus, Tick, Vectorial capacity",
author = "Vredevoe, {Larisa K.} and Richter, {Phillip J.} and Madigan, {John E} and Kimsey, {Robert B.}",
year = "1999",
month = "9",
language = "English (US)",
volume = "36",
pages = "551--561",
journal = "Journal of Medical Entomology",
issn = "0022-2585",
publisher = "Entomological Society of America",
number = "5",

}

TY - JOUR

T1 - Association of Ixodes pacificus (Acari

T2 - Ixodidae) with the spatial and temporal distribution of equine granulocytic ehrlichiosis in California

AU - Vredevoe, Larisa K.

AU - Richter, Phillip J.

AU - Madigan, John E

AU - Kimsey, Robert B.

PY - 1999/9

Y1 - 1999/9

N2 - 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 cities of practice were distributed, with foci limited to the Sierra Nevada and coastal foothills. Cases also clustered seasonally; most were diagnosed between November and April. The spatial and temporal pattern of EGE cases closely parallels the well-characterized life history and distribution of Ixodes pacificus Cooley & Kohls, but not other ticks commonly associated with horses. Building on previous studies, there is compelling evidence that this tick has the vectorial capacity to transmit Ehrlichia equi to horses. Based on the life history and distribution of I. pacificus in relation to EGE cases, we reason that this tick is the only biologically plausible vector of E. equi in California, and provide evidence for a tightly linked association between I. pacificus and the epidemiology of EGE.

AB - 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 cities of practice were distributed, with foci limited to the Sierra Nevada and coastal foothills. Cases also clustered seasonally; most were diagnosed between November and April. The spatial and temporal pattern of EGE cases closely parallels the well-characterized life history and distribution of Ixodes pacificus Cooley & Kohls, but not other ticks commonly associated with horses. Building on previous studies, there is compelling evidence that this tick has the vectorial capacity to transmit Ehrlichia equi to horses. Based on the life history and distribution of I. pacificus in relation to EGE cases, we reason that this tick is the only biologically plausible vector of E. equi in California, and provide evidence for a tightly linked association between I. pacificus and the epidemiology of EGE.

KW - Ehrlichia

KW - Ehrlichia equi

KW - Equine ehrlichiosis

KW - Ixodes pacificus

KW - Tick

KW - Vectorial capacity

UR - http://www.scopus.com/inward/record.url?scp=0033195412&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033195412&partnerID=8YFLogxK

M3 - Article

VL - 36

SP - 551

EP - 561

JO - Journal of Medical Entomology

JF - Journal of Medical Entomology

SN - 0022-2585

IS - 5

ER -