Prevalence of Rickettsia species in Dermacentor variabilis ticks from Ontario, Canada.
Relatively little is known about the prevalence of rickettsial species in Dermacentor ticks in eastern Canada. In this study, Dermacentor ticks from the province of Ontario, Canada, were tested for the presence of spotted fever group rickettsial (SFGR) species, Coxiella burnetii and Francisella tularensis. Rickettsia rickettsii was not detected in any ticks tested, but R. montanensis was detected at a prevalence of 2.2% in D. variabilis (17/778). Two other SFGR species, R. parkeri and Candidatus R. andeanae, were detected individually in 2 Amblyomma maculatum ticks. Rickettsia peacockii, a non-pathogenic endosymbiont, was detected in two D. andersonii ticks. Given the highly abundant nature of D. variabilis, surveillance for human pathogens in this species of tick has important public health implications, but the lack of detection of known human pathogens indicates a low risk of infection via this tick species in Ontario. However, the detection of R. parkeri in an adventive A. maculatum tick indicates that health care providers should be aware of the possibility of spotted fever rickettsioses in individuals with a history of travel outside of Ontario and symptoms compatible with a spotted fever rickettsiosis. Coxiella burnetii and Francisella tularensis, human pathogens also potentially transmitted by D. variabilis, were not detected in a subset of the ticks.
National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada. Electronic address: Heidi.Wood@phac-aspc.gc.ca.
Heidi
H
Wood
National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada. Electronic address: Liz.Dillon@phac-aspc.gc.ca.
Liz
L
Dillon
Public Health Ontario Laboratory, Public Health Ontario, Toronto, Ontario, Canada. Electronic address: Samir.Patel@oahpp.ca.
Samir N
SN
Patel
Public Health Ontario Laboratory, Public Health Ontario, Toronto, Ontario, Canada. Electronic address: Filip.Ralevski@oahpp.ca.
Filip
F
Ralevski
D000818:Animals; D001096:Arachnid Vectors / Q000382:microbiology*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D016997:Coxiella burnetii / Q000235:genetics / Q000302:isolation & purification; D003870:Dermacentor / Q000382:microbiology*; D005604:Francisella tularensis / Q000235:genetics / Q000302:isolation & purification; D009864:Ontario / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012281:Rickettsia / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D012284:Rickettsia rickettsii / Q000235:genetics / Q000302:isolation & purification
D001425:Bacterial Outer Membrane Proteins; C078167:OMPA outer membrane proteins
Canada; Dermacentor ticks; Spotted fever group rickettsiae