title: Experimental infection of calves, sheep, goats and pigs with HoBi-like viruses by direct inoculation or exposure to persistently infected calves.
abstract: HoBi-like viruses are an emerging species of pestiviruses associated with respiratory and reproductive disease in cattle and in water buffaloes. Although cattle appear to be the main natural hosts, little is know about the potential for HoBi-like viruses to be transmitted to other livestock. In this study, seronegative calves, goats and pigs, and sheep harboring pestivirus antibodies (probably due to previous exposure to BVDV) were exposed to HoBi-like viruses either by direct inoculation (GIn) or by contact with calves persistently infected with HoBi-like viruses (GEx). Both GIn and GEx groups were monitored for clinical signs, lymphocyte count, virus in buffy coats and nasal swabs up to day 18 post-inoculation (pi). Evidence of transmission of HoBi-like virus by PI calves was observed in all studied species. No difference in clinical presentation was observed between animals in the GIn or GEx groups. Evidence of infection, depending on the species included lymphocyte depletion, fever, viral RNA detection, and/or seroconversion. Depletion of lymphocytes was observed in calves and goats (35% and 50%, respectively) but not in pigs. Seroconversion was observed in at least one animal of each group and for all exposed species. The rate of seroconversion was higher in animals in the GIn experimental groups. In sheep, pre-existing moderate to high neutralizing titers against BVDV did not prevent viral replication and shed. The study demonstrated that naive cattle, goats and pigs, in addition to antibody positive sheep, can be infected by HoBi-like virus via persistently infected calf and potentially transmit the virus.
authors.affiliation: Ruminant Disease and Immunology Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, P.O. Box 70, Ames, IA 50010, USA; Universidade Federal de Santa Maria, Santa Maria, RS 97015040, Brazil. Electronic address: Fernando.bauermann@ars.usda.gov.
authors.forename: F V
authors.initials: FV
authors.lastname: Bauermann
authors.affiliation: Elanco Animal Health, Vaccine Development, 2500 Innovation Way, Greenfield, IN 46160, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Falkenberg
authors.affiliation: Department of Veterinary Medicine, University of Bari, Valenzano, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Decaro
authors.affiliation: Universidade Federal de Santa Maria, Santa Maria, RS 97015040, Brazil.
authors.forename: E F
authors.initials: EF
authors.lastname: Flores
authors.affiliation: Ruminant Disease and Immunology Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, P.O. Box 70, Ames, IA 50010, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Ridpath
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D002417:Cattle / Q000821:virology*; D006041:Goats / Q000821:virology*; D010576:Pestivirus / Q000472:pathogenicity*; D018182:Pestivirus Infections / Q000276:immunology / Q000662:veterinary*; D012367:RNA, Viral / Q000302:isolation & purification; D034561:Sheep, Domestic / Q000821:virology*; D034421:Sus scrofa / Q000821:virology*; D014611:Vaccination; D017201:Virus Shedding
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D012367:RNA, Viral
keywords: Bovine viral diarrhea virus; Clinical signs; Epidemiology; Pestivirus; Transmission