Excerpt:

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 PCR-positive 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.