Persistent Ehrlichia ewingii Infection in Dogs after Natural Tick Infestation
نویسندگان
چکیده
BACKGROUND Ehrlichia ewingii, which causes disease in dogs and people, is the most common Ehrlichia spp. infecting dogs in the United States, but little is known about how long E. ewingii infection persists in dogs. HYPOTHESIS/OBJECTIVES To evaluate the persistence of natural infection with E. ewingii in dogs. ANIMALS Four Class A Beagles; no previous exposure to ticks or tick-borne infectious agents. METHODS Dogs were exposed to ticks by weekly walks through tick habitat in north central Oklahoma; dogs positive for infection with Ehrlichia spp. by sequence-confirmed PCR and peptide-specific serology were evaluated for 733 days (D). Whole blood was collected once weekly for PCR, and serum was collected once monthly for detection of antibodies to Ehrlichia canis (peptide p16), Ehrlichia chaffeensis (indirect fluorescence antibody [IFA] and variable-length PCR target [VLPT]), and E. ewingii (peptide p28). RESULTS All dogs (4/4) became infected with Ehrlichia spp. as evidenced by seroconversion on IFA to E. chaffeensis (4/4); PCR detection of E. ewingii (4/4) and E. chaffeensis (2/4) DNA using both nested and real-time assays; and presence of specific antibodies to E. ewingii (4/4) and E. chaffeensis (2/4). Infection with E. chaffeensis was not detected after D55. Intermittent E. ewingii rickettsemia persisted in 3 of 4 dogs for as long as 733 days. CONCLUSIONS AND CLINICAL IMPORTANCE Our data demonstrate that dogs infected with E. ewingii from tick feeding are capable of maintaining infection with this pathogen long-term, and may serve as a reservoir host for the maintenance of E. ewingii in nature.
منابع مشابه
Ehrlichia ewingii Infection in White-Tailed Deer (Odocoileus virginianus)
Two closely related zoonotic ehrlichiae, Ehrlichia chaffeensis and E. ewingii, are transmitted by Amblyomma americanum, the lone star tick. Because white-tailed deer (Odocoileus virginianus) are critical hosts for all mobile stages of A. americanum and are important vertebrate reservoirs of E. chaffeensis, we investigated whether deer may be infected with E. ewingii, a cause of granulocytotropi...
متن کاملA serological survey of tick-borne pathogens in dogs in North America and the Caribbean as assessed by Anaplasma phagocytophilum, A. platys, Ehrlichia canis, E. chaffeensis, E. ewingii, and Borrelia burgdorferi species-specific peptides
INTRODUCTION Tick-borne pathogens cause a spectrum of disease manifestations in both dogs and humans. Recognizing regional and temporal shifts in exposure are important as tick distributions change. To better delineate regional exposure to canine tick-borne pathogens, an expanded set of species-specific peptides were used to detect Anaplasma phagocytophilum (Aph), Anaplasma platys (Apl), Ehrlic...
متن کاملIs the detection of anti-Rhipicephalus sanguineus (Rs24p) antibodies a valuable epidemiological tool of tick infestation in dogs?
Antibodies against the 24 kDa Rhipicephalus sanguineus (Rs24p) protein were detected by ELISA to evaluate the relationship between antibodies and tick infestation. The mean titer of 3 dogs that underwent 2 experimental infestations with adult ticks was transiently increased after the second infestation. There was a significant difference in mean titers between positive control dogs naturally in...
متن کاملPrevalence of Ehrlichia ewingii in Amblyomma americanum in North Carolina.
Ticks as vectors of Ehrlichia parasites have been the subject of study in North Carolina since 1993. Recently, Ehrlichia ewingii, which causes canine granulocytic ehrlichiosis, was documented as causing human illness in Missouri (3). Previously, the Lone Star tick, Amblyomma americanum, was confirmed as the vector of this parasite in dogs (2). Accordingly, in 1999, we focused our efforts on det...
متن کاملInfection of Anaplasma phagocytophilum and Ehrlichia spp. in Opossums and Dogs in Campeche, Mexico: The Role of Tick Infestation
In recent years, some tick-borne diseases such as anaplasmosis and ehrlichiosis became widespread worldwide, threatening the health of humans, domestic animals and wildlife. The aims of this study were to determine the presence of Anaplasma phagocytophilum, Ehrlichia canis, and Ehrlichia chaffeensis in 102 opossums (Didelphis spp.) and 44 owned free-ranging dogs in southeastern Mexico using a s...
متن کامل