title: Prevalence of the causative agents of equine piroplasmosis in the South West of The Netherlands and the identification of two autochthonous clinical Theileria equi infections.
abstract: Equine piroplasmosis (EP) has not been considered indigenous in The Netherlands. However, following the detection of an apparently indigenous subclinical Babesia caballi infection in a horse on Schouwen-Duiveland (an island in the Zeeland Province), a survey was undertaken between May and September 2010 to assess the prevalence of the causative agents of EP in the South-West of The Netherlands. Blood samples from 300 randomly selected horses were tested for specific antibodies against Theileria equi and B. caballi using an indirect fluorescence antibody test (IFAT), and for parasite DNA using a specific polymerase chain reaction combined with reverse line blotting (PCR-RLB). Twelve of the horses (4%) were seropositive for EP. Of these, nine (75%) were positive (titre⩾1:160) for B. caballi alone and three (25%) were also positive for T. equi. PCR-RLB detected T. equi DNA in five horses (1.6%), two of which were seronegative. Four (1.3%) of the positive horses (three positive for T. equi and one for both B. caballi and T. equi) were considered truly indigenous. During the study, two indigenous ponies from a farm situated outside the sampling area were diagnosed with acute clinical piroplasmosis characterized by severe anaemia and pyrexia. Blood smears showed T. equi - like inclusions in red blood cells, and T. equi infection was confirmed in both ponies by PCR-RLB. The initial subclinical B. caballi infection, the survey results and the two acute clinical EP cases confirmed the autochthonous transmission of B. caballi and T. equi infections in The Netherlands.
authors.affiliation: Department of Equine Sciences, Utrecht University, Yalelaan 114, 3584 CM Utrecht, The Netherlands.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Butler
authors.forename: Marianne M
authors.initials: MM
authors.lastname: Sloet van Oldruitenborgh-Oosterbaan
authors.forename: Tom A E
authors.initials: TA
authors.lastname: Stout
authors.forename: Johannus H
authors.initials: JH
authors.lastname: van der Kolk
authors.forename: Linda van den
authors.initials: Lv
authors.lastname: Wollenberg
authors.forename: Mirjam
authors.initials: M
authors.lastname: Nielen
authors.forename: Frans
authors.initials: F
authors.lastname: Jongejan
authors.forename: Arno H
authors.initials: AH
authors.lastname: Werners
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Houwers
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D058345:Asymptomatic Infections / Q000453:epidemiology; D001399:Azure Stains / Q000737:chemistry; D001403:Babesia / Q000276:immunology / Q000302:isolation & purification*; D001404:Babesiosis / Q000097:blood / Q000453:epidemiology / Q000662:veterinary*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000662:veterinary; D006734:Horse Diseases / Q000097:blood / Q000453:epidemiology*; D006736:Horses; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D015995:Prevalence; D016036:Seroepidemiologic Studies; D016794:Theileria / Q000276:immunology / Q000302:isolation & purification*; D013801:Theileriasis / Q000097:blood / Q000453:epidemiology*
chemical_list: D000913:Antibodies, Protozoan; D001399:Azure Stains