Coinfection of Western Gray Squirrel (Sciurus griseus) and other Sciurid Rodents with Borrelia burgdorferi sensu stricto and Anaplasma phagocytophilum in California

Abstract

ABSTRACT:Overlapping geographic distributions of tick-borne disease agents utilizing the same tick vectors are common, and coinfection of humans, domestic animals, wildlife, and ticks with both Borrelia burgdorferi and Anaplasma phagocytophilum has been frequently reported. This study was undertaken in order to evaluate the prevalence of both B. burgdorferi sensu stricto (hereinafter referred to as B. burgdorferi) and A. phagocytophilum in several species of sciurid rodents from northern California, USA. Rodents were either collected dead as road-kills or live-trapped in four state parks from 13 counties. Thirty-seven western gray squirrels (Sciurus griseus), nine nonnative eastern gray squirrels (S. carolinensis) and an eastern fox squirrel (S. niger), four Douglas squirrels (Tamiasciurus douglasii), and two northern flying squirrels (Glaucomys sabrinus) were tested by polymerase chain reaction (PCR) and serology for evidence of coinfection. Of the 14 individual S. griseus that were PCRpositive for B. burgdorferi, two (14%) also were PCR-positive for A. phagocytophilum and 11 (79%) had serologic evidence of A. phagocytophilum exposure. Two of the four Douglas squirrels were PCR positive for B. burgdorferi and seropositive to A. phagocytophilum. Evidence of coinfection with these zoonotic pathogens in western gray squirrels suggests that both bacteria may be maintained in a similar transmission cycle involving this sciurid and the western black-legged tick Ixodes pacificus, the primary bridging vector to humans in the far-western US.

Assessment of a quantitative 5′ nuclease real-time polymerase chain reaction using groEL gene for Ehrlichia and Anaplasma species in rodents in Brazil

“…rodent species are recognized as important sources of infections for the HZ, MRK and Dog_CA strains of An. phagocytophilum in the USA (Nieto et al, 2010).…”

Anaplasma phagocytophilum—a widespread multi-host pathogen with highly adaptive strategies

“…Prevalence ranges from 1.8 to 88.4%. The gray squirrel ( Sciurus carolinensis ) has also been found to be reservoir competent (Levin et al, 2002) and the redwood chipmunk ( Tamias ochrogenys ) and sciurid rodents are discussed as important reservoir hosts for A. phagocytophilum in the Western US (Nieto et al, 2010; Foley and Nieto, 2011). Similarly to other small mammals that have been suggested to maintain niche cycles, the redwood chipmunk hosts both antropophilic ( I. pacificus ) and nidicolous ( I. angustus ) ticks (Foley and Nieto, 2011).…”

Anaplasma phagocytophilum in Questing Ixodes ricinus Ticks: Comparison of Prevalences and Partial 16S rRNA Gene Variants in Urban, Pasture, and Natural Habitats

“…In urban sites R1 and M2, (12,24). Furthermore, as wild ungulates are rare to nonexistent on study sites R1 and M2, there must be other reservoir hosts present, such as foxes, small rodents, hedgehogs, squirrels, or birds (13,(17)(18)(19)(20)(21). Variant A has also been detected in a human patient (22) and in granulocytic anaplasmosis cases in horses and dogs (3,4).…”