title: Schmallenberg virus experimental infection of sheep.
abstract: Since late 2011, a novel orthobunyavirus, named Schmallenberg virus (SBV), has been implicated in many cases of severely malformed bovine and ovine offspring in Europe. In adult cattle, SBV is known to cause a mild transient disease; clinical signs include short febrile episodes, decreased milk production and diarrhoea for a few days. However, the knowledge about clinical signs and pathogenesis in adult sheep is limited. In the present study, adult sheep of European domestic breeds were inoculated with SBV either as cell culture grown virus or as virus with no history of passage in cell cultures. Various experimental set-ups were used. Sampling included blood collection at different time points during the experimental period and selected organ material at autopsy. Data from this study showed, that the RNAemic period in sheep was as short as reported for cattle; viral genome was detectable for about 3-5 days by real-time RT-PCR. In total, 13 out of 30 inoculated sheep became RNAemic, with the highest viral load in animals inoculated with virus from low cell culture passaged or the animal passaged material. Contact animals remained negative throughout the study. One RNAemic sheep showed diarrhoea for several days, but fever was not recorded in any of the animals. Antibodies were first detectable 10-14 days post inoculation. Viral RNA was detectable in spleen and lymph nodes up to day 44 post inoculation. In conclusion, as described for cattle, SBV-infection in adult sheep predominantly results in subclinical infection, transient RNAemia and a specific antibody response. Maintenance of viral RNA in the lymphoreticular system is observed for an extended period.
authors: Institute of Diagnostic Virology, Friedrich-Loeffler-Institut (FLI), Suedufer 10, 17493 Greifswald - Insel Riems, Germany.
authors: Kerstin
authors: K
authors: Wernike
authors: Bernd
authors: B
authors: Hoffmann
authors: Emmanuel
authors: E
authors: Bréard
authors: Anette
authors: A
authors: Bøtner
authors: Claire
authors: C
authors: Ponsart
authors: Stéphan
authors: S
authors: Zientara
authors: Louise
authors: L
authors: Lohse
authors: Nathalie
authors: N
authors: Pozzi
authors: Cyril
authors: C
authors: Viarouge
authors: Pierre
authors: P
authors: Sarradin
authors: Céline
authors: C
authors: Leroux-Barc
authors: Mickael
authors: M
authors: Riou
authors: Eve
authors: E
authors: Laloy
authors: Angele
authors: A
authors: Breithaupt
authors: Martin
authors: M
authors: Beer
mesh_terms: D000818:Animals; D002044:Bunyaviridae Infections / Q000175:diagnosis / Q000662:veterinary* / Q000821:virology; D005060:Europe; D005260:Female; D008297:Male; D016851:Orthobunyavirus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D012367:RNA, Viral / Q000235:genetics; D012756:Sheep; D012757:Sheep Diseases / Q000175:diagnosis / Q000821:virology*
chemical_list: D012367:RNA, Viral
keywords: Experimental infection; Orthobunyavirus; Schmallenberg virus; Sheep