title: Pulmonary artery haemorrhage in newborn calves following bluetongue virus serotype 8 experimental infections of pregnant heifers.
abstract: The emergence of bluetongue disease (BT) among livestock in Europe in 2006 raised many questions including the occurrence and epidemiological significance of foetal infections in cattle. To clarify these aspects, vaccinated and unvaccinated pregnant heifers were sequentially infected twice in an isolation facility (biosafety level 3) with a northern European outbreak strain of Bluetongue virus serotype 8 (BTV-8). The study was terminated 2 months after calving with necropsy of the dams and their offspring. The cattle were monitored throughout the study by clinical scoring and for the presence of circulating neutralising antibodies, and after calving for the presence of infectious virus and viral RNA in blood and milk. Four calves, one born from a vaccinated dam and three from non-vaccinated ones, that were infected at 120 days of gestation had obvious haemorrhage of the pulmonary artery at necropsy. Although haemorrhage of the pulmonary artery is highly characteristic of BT, viral RNA was not detected in any of these calves. Furthermore, although none of the calves born from heifers infected prior to mid-gestation had teratogenic BTV typical brain lesions, some had lesions at birth suggestive of in utero BTV infection. Despite the lack of viral RNA detection, the presence of haemorrhage of the pulmonary artery deserves to be reported as a new observation in the context of the multiple investigations having as main subject the BTV placental crossing in cattle.
authors.affiliation: Research Unit of Epidemiology and Risk Analysis Applied to the Veterinary Sciences (UREAR-ULg), Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, Boulevard de Colonster 20, B-4000 Liège, Belgium.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Martinelle
authors.forename: Fabiana
authors.initials: F
authors.lastname: Dal Pozzo
authors.forename: Pierre
authors.initials: P
authors.lastname: Sarradin
authors.forename: Ilse
authors.initials: I
authors.lastname: De Leeuw
authors.forename: Kris
authors.initials: K
authors.lastname: De Clercq
authors.forename: Christine
authors.initials: C
authors.lastname: Thys
authors.forename: Etienne
authors.initials: E
authors.lastname: Thiry
authors.forename: Claude
authors.initials: C
authors.lastname: Saegerman
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000276:immunology; D000914:Antibodies, Viral / Q000032:analysis / Q000097:blood; D001819:Bluetongue / Q000175:diagnosis / Q000276:immunology / Q000473:pathology*; D001820:Bluetongue virus / Q000502:physiology; D001921:Brain / Q000473:pathology; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis / Q000276:immunology / Q000473:pathology*; D005060:Europe; D005260:Female; D008892:Milk / Q000276:immunology; D010920:Placenta / Q000473:pathology; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000473:pathology / Q000662:veterinary*; D011651:Pulmonary Artery / Q000473:pathology*; D012367:RNA, Viral / Q000032:analysis / Q000097:blood; D012756:Sheep; D014611:Vaccination / Q000662:veterinary
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D012367:RNA, Viral
keywords: Bluetongue disease; Experimental infection; Haemorrhage; Pulmonary artery; Transplacental