Submitted to: Transboundary and Emerging Diseases
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/30/2013
Publication Date: 2/1/2016
Publication URL: http://handle.nal.usda.gov/10113/61252
Citation: Weber, M.N., Mosena, A.C., Simoes, V.D., Almeida, L.L., Pessoa, C.R., Budaszewski, R.F., Silva, T.R., Ridpath, J.F., Riet-Correa, F., Driemeier, D., Canal, C.W. 2016. Clinical presentation resembling mucosal disease associated with 'HoBi'-like pestivirus in a field outbreak. Transboundary and Emerging Diseases. 63(1):92-100. doi: 10.1111/tbed.12223. Interpretive Summary: Pestiviruses are a group of viruses that cause economically import diseases in the livestock industry. Recently a new member of this group called "Hobi-like viruses" have been isolated from cattle during outbreaks of respiratory or reproductive disease. The clinical signs noted during these outbreaks were very similar to another type of pestivirus that infects cattle, known as bovine viral diarrhea virus (BVDV). In addition to reproductive and respiratory disease, BVDV also cause a highly fatal disease called mucosal disease (MD). MD occurs when a calf persistently infected with a noncytopathic BVDV is super infected with a cytopathic BVDV. In this report, the authors describe an case in which a calf presented with MD like symptoms but was infected with HoBi-like virus rather than BVDV. This is the first report of MD caused by a pestivirus other than BVDV. In the past animals presenting with MD like symptoms were assumed to have been infected with BVDV. This report suggests that diagnosticians must do a differential diagnosis to determine if the pestivirus causing MD is a BVDV or a HoBi-like virus.
Technical Abstract: The genus Pestivirus of the family Flaviviridae consists of four recognized species: Bovine viral diarrhea virus 1 (BVDV-1), Bovine viral diarrhea virus 2 (BVDV-2), Classical swine fever virus (CSFV) And Border disease virus (BDV). Recently, atypical pestiviruses (‘HoBi’-like pestiviruses) were identified in batches of contaminated foetal calf serum and in naturally infected cattle with and without clinical symptoms. Here, we describe the first report of a mucosal disease-like clinical presentation (MD) associated with a ‘HoBi’-like pestivirus occurring in a cattle herd. The outbreak was investigated using immunohistochemistry, antibody detection, viral isolation and RT-PCR. The sequence and hylogenetic analysis of 50NCR, Npro and E2 regions of the RT-PCR positive samples showed that four different ‘HoBi’-like strains were circulating in the herd. The main clinical signs and lesions were observed in the respiratory and digestive systems, but skin lesions and corneal opacity were also observed. MD characteristic lesions and a pestivirus with cytopathic biotype were detected in one calf. The present study is the first report of a MD like presentation associated with natural infection with ‘HoBi’-like pestivirus. This report describes the clinical signs and provides a pathologic framework of an outbreak associated with at least two different ‘HoBi’-like strains. Based on these observations, it appears that these atypical pestiviruses are most likely underdiagnosed in Brazilian cattle.