title: Use of competition ELISA for monitoring of West Nile virus infections in horses in Germany.
abstract: West Nile virus (WNV) is a mosquito-borne viral pathogen of global importance and is considered to be the most widespread flavivirus in the World. Horses, as dead-end hosts, can be infected by bridge mosquito vectors and undergo either subclinical infections or develop severe neurological diseases. The aim of this study was to detect WNV specific antibodies in horses in Germany as an indicator for an endemic circulation of WNV. Sera from more than 5,000 horses (primarily fallen stock animals) were collected in eight different federal states of Germany from 2010 to 2012. Sera were screened by a competitive ELISA and positive reactions were verified by an indirect IgM ELISA and/or by virus neutralization tests (VNT) for WNV and Tick-borne encephalitis virus (TBEV) in order to exclude cross-reacting antibody reactions. In essence WNV specific antibodies could not be detected in any of the horse sera. Not surprisingly, a small number of sera contained antibodies against TBEV. It is noteworthy that equine sera were often collected from horse carcasses and therefore were of poor quality. Nonetheless, these sera were still suitable for WNV ELISA testing, i.e., they did not produce a high background reaction which is a frequently observed phenomenon. According to these data there is no evidence for indigenous WNV infections in horses in Germany at present.
authors.affiliation: Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Südufer 10, D-17493 Greifswald-Insel Riems, Germany. ute.ziegler@fli.bund.de
authors.forename: Ute
authors.initials: U
authors.lastname: Ziegler
authors.forename: Joke
authors.initials: J
authors.lastname: Angenvoort
authors.forename: Christine
authors.initials: C
authors.lastname: Klaus
authors.forename: Uschi
authors.initials: U
authors.lastname: Nagel-Kohl
authors.forename: Claudia
authors.initials: C
authors.lastname: Sauerwald
authors.forename: Sabine
authors.initials: S
authors.lastname: Thalheim
authors.forename: Steffen
authors.initials: S
authors.lastname: Horner
authors.forename: Bettina
authors.initials: B
authors.lastname: Braun
authors.forename: Susanne
authors.initials: S
authors.lastname: Kenklies
authors.forename: Judith
authors.initials: J
authors.lastname: Tyczka
authors.forename: Markus
authors.initials: M
authors.lastname: Keller
authors.forename: Martin H
authors.initials: MH
authors.lastname: Groschup
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D000918:Antibody Specificity; D003429:Cross Reactions; D004669:Encephalitis Viruses, Tick-Borne / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005416:Flavivirus; D005858:Germany / Q000453:epidemiology; D006734:Horse Diseases / Q000453:epidemiology*; D006736:Horses; D016036:Seroepidemiologic Studies; D014901:West Nile Fever / Q000453:epidemiology / Q000662:veterinary*; D014902:West Nile virus / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral