Prevalentie van Ehrlichia canis in Rhipicephalus sanguineus teken uit het Caribisch gebied

Abstract

Ehrlichiosis is an important tick-borne bacterial disease and is commonly diagnosed on dogs in the Caribbean. The brown dog tick Rhipicephalus sanguineus - the only known vector of Ehrlichia canis- is endemic in this area and frequently detected on dogs. Besides E. canis this tick can also transmit the protozoal parasites Babesia vogeli and Babesia gibsoni. Further it has been recognized - but not confirmed – as a vector of Anaplasma platys and Leishmania infantum. In this current study is attempted with use of molecular dectection which of these tick-borne pathogens are present in R. sanguineus ticks from the island Curaçao in the Caribbean. The purpose was to investigate the prevalence of E.canis and to identify other tick-borne pathogens suspected to be present in this tickpopulation. A total of 360 tick pools were screened for Ehrlichia/Anaplasma, Babesia/ Theileria and Leishmania species using PCR and Reverse Line Blot hybridization. On RLB 133 tick pools (36,9%, n=360) were positive for one ore more species; 95 samples for E. canis (26,4%, n=360); 27 samples for Anaplasma phagocytophilum (7,5%, n=360); 4 samples for Babesia venatorum; 3 for Ehrlichia/Anaplasma catch-all; 3 for Babesia catch-all; and 1 sample for Anaplasma marginale. No ticks were found positive for Leishmania species. Of the 95 tick pools positive for E. canis, were 55 samples (57,9%, n=95) mixed infections; either co-infected with Anaplasma species (51/95) or nonspecific Babesia species (4/95). These results demonstrate a high prevalence of E. canis circulating in the R. sanguineus tickpopulation at the island Curaçao. Detection of Anaplasma phagocytophilum and Babesia venatorum is a surprising finding since the vector Ixodes ricinus is not present on this island. For the exact species identification is further labwork required by DNA sequencing.