title: Experimental infection of South American camelids with bluetongue virus serotype 8.
abstract: Bluetongue (BT) is an infectious, non-contagious disease of wild and domestic ruminants. It is caused by bluetongue virus (BTV) and transmitted by Culicoides biting midges. Since 1998, BT has been emerging throughout Europe, threatening not only the naïve ruminant population. Historically, South American camelids (SAC) were considered to be resistant to BT disease. However, recent fatalities related to BTV in captive SAC have raised questions about their role in BTV epidemiology. Data on the susceptibility of SAC to experimental infection with BTV serotype 8 (BTV-8) were collected in an animal experiment. Three alpacas (Vicugna pacos) and three llamas (Lama glama) were experimentally infected with BTV-8. They displayed very mild clinical signs. Seroconversion was first measured 6-8 days after infection (dpi) by ELISA, and neutralising antibodies appeared 10-13 dpi. BTV-8 RNA levels in blood were very low, and quickly cleared after seroconversion. However, spleens collected post-mortem were still positive for BTV RNA, over 71 days after the last detection in blood samples. Virus isolation was only possible from blood samples of two alpacas by inoculation of highly sensitive interferon alpha/beta receptor-deficient (IFNAR(-/-)) mice. An in vitro experiment demonstrated that significantly lower amounts of BTV-8 adsorb to SAC blood cells than to bovine blood cells. Although this experiment showed that SAC are generally susceptible to a BTV-8 infection, it indicates that these species play a negligible role in BTV epidemiology.
authors.affiliation: Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Schulz
authors.forename: Michael
authors.initials: M
authors.lastname: Eschbaumer
authors.forename: Miriam
authors.initials: M
authors.lastname: Rudolf
authors.forename: Patricia
authors.initials: P
authors.lastname: König
authors.forename: Markus
authors.initials: M
authors.lastname: Keller
authors.forename: Christian
authors.initials: C
authors.lastname: Bauer
authors.forename: Matthias
authors.initials: M
authors.lastname: Gauly
authors.forename: Christoph G
authors.initials: CG
authors.lastname: Grevelding
authors.forename: Martin
authors.initials: M
authors.lastname: Beer
authors.forename: Bernd
authors.initials: B
authors.lastname: Hoffmann
mesh_terms: D000818:Animals; D001819:Bluetongue / Q000276:immunology*; D001820:Bluetongue virus / Q000235:genetics*; D002161:Camelids, New World / Q000821:virology*; D002417:Cattle; D002519:Ceratopogonidae / Q000821:virology; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D004912:Erythrocytes / Q000821:virology; D005060:Europe / Q000453:epidemiology; D008297:Male; D051379:Mice; D053633:Receptor, Interferon alpha-beta / Q000378:metabolism; D013552:Swine
chemical_list: D053633:Receptor, Interferon alpha-beta