Detection and analysis of tick-borne infections in communal dogs of northwest Zimbabwe

Abstract

Domestic dogs (Canis familiaris) may serve as a reservoir or a sentinel for infectious disease pathogens that can affect human and wildlife health. To understand the role of tick-borne diseases in rural and lesser developed regions, we investigated the prevalence of several tick-borne pathogens in communal dogs of Zimbabwe. Blood samples from 225 dogs in northwest Zimbabwe were assessed by serology for Ehrlichia canis, Anaplasma phagocytophilum and Borrelia burgdorferi, and 241 samples were assessed by polymerase chain reaction (PCR) for Ehrlichia. There was a high seroprevalence (73%) of E. canis-specific antibodies in domestic dogs in northwest Zimbabwe, but follow up analyses via PCR and genetic sequencing indicated only 7.5% of the canines were actively infected with the organism. Whilst indicating that an organism serologically related to E. canis is likely present in the region, this data also shows that the organism is currently present in a relative minority of the domestic dogs in the region. Its presence as evidenced by both serologic and PCR analysis is significant because of the 'one health' paradigm, where humans and wildlife may be affected by the exposure to this pathogen in domestic dogs.

Keywords: Ehrlichia; Southern Africa; canine; one health; tick.