Bovint coronavirus hos kalv : virusutskilling, overføring og fullgenomsekvensering

The two most costly infections in Norwegian cattle. Is it possible to control bovine respiratory syncytial virus and bovine coronavirus?Bovine coronavirus (BCoV) is a significant cause of respiratory disease and diarrhea in calves and of winter dysentery in adult cattle. These endemic diseases result in substantial economic losses and reduced animal welfare in cattle worldwide. Inter-herd transmission can occur directly, with contact between live animals, or indirectly, via contaminated personnel and equipment. This thesis aims to elucidate transmission of BCoV via animals, contaminated personnel and equipment, and to develop methods for tracing of the virus.Bovint coronavirus (BCoV) er ein viktig årsak til luftvegssjukdom og diaré hos kalvar og vinterdysenteri hos vaksne. Desse sjukdommane fører til store økonomiske tap og redusert dyrevelferd hos storfe over heile verda. Smitte mellom besetningar kan skje ved direkte kontakt mellom levande dyr eller indirekte, ved personar og utstyr som drar mellom besetningar. Denne avhandlinga tar for seg smitteoverføring av viruset, både mellom dyr og via forureina utstyr og personar, og metodar for å spore virusoverføringar.TINE Norwegian Dairies SA ; The Norwegian Research Funding for Agriculture and Food Industr

Bovine coronavirus in calves : experimental studies on virus shedding, transmission and whole genome sequencing

Bovine coronavirus (BCoV) is a significant cause of respiratory disease and diarrhea in calves and of winter dysentery in adult cattle. These endemic diseases result in substantial economic losses and reduced animal welfare in cattle worldwide. Inter-herd transmission can occur directly, with contact between live animals, or indirectly, via contaminated personnel and equipment. This thesis aims to elucidate transmission of BCoV via animals, contaminated personnel and equipment, and to develop methods for tracing of the virus

Genome Sequence of a Bovine Rhinitis B Virus Identified in Cattle in Sweden

publishedVersio

Single primer isothermal amplification (SPIA) combined with next generation sequencing provides complete bovine coronavirus genome coverage and higher sequence depth compared to sequence-independent single primer amplification (SISPA)

publishedVersio

Temporary carriage of bovine coronavirus and bovine respiratory syncytial virus by fomites and human nasal mucosa after exposure to infected calves

Abstract Background In order to prevent spread of the endemic pathogens bovine coronavirus (BCoV) and bovine respiratory syncytial virus (BRSV) between herds, knowledge of indirect transmission by personnel and fomites is fundamental. The aims of the study were to determine the duration of viral RNA carriage and the infectivity of viral particles on fomites and human nasal mucosa after exposure to BCoV and BRSV. During two animal infection experiments, swabs were collected from personnel (nasal mucosa) and their clothes, boots and equipment after contact with calves shedding either virus. Viral RNA was quantified by RT-qPCR or droplet digital RT-PCR (RT-ddPCR), and selected samples with high levels of viral RNA were tested by cell culture for infectivity. Results For BCoV, 46% (n = 80) of the swabs from human nasal mucosa collected 30 min after exposure were positive by RT-qPCR. After two, four and six hours, 15%, 5% and 0% of the swabs were positive, respectively. Infective virions were not detected in mucosal swabs (n = 2). A high viral RNA load was detected on 97% (n = 44) of the fomites 24 h after exposure, and infective virions were detected in two of three swabs. For BRSV, 35% (n = 26) of the human nasal mucosa swabs collected 30 min after exposure, were positive by RT-ddPCR, but none were positive for infective virions. Of the fomites, 89% (n = 38) were positive for BRSV RNA 24 h after exposure, but all were negative for infective viruses. Conclusions The results indicate that human nasal mucosa can carry both BCoV and BRSV RNA after exposure to virus shedding calves, but the carriage seems short-lived and the transmission potential is likely limited. High viral loads on contaminates fomites 24 h after exposure to infected animals, and detection of infective BCoV, indicate that contaminated fomites represent a significant risk for indirect transmission between herds

Using Biosecurity Measures to Combat Respiratory Disease in Cattle: The Norwegian Control Program for Bovine Respiratory Syncytial Virus and Bovine Coronavirus

Bovine respiratory disease (BRD) cause important health problems in all cattle husbandry systems. It contributes substantially to the use of antimicrobial substances and compromises animal welfare and the sustainability of the cattle industry. The existing preventive measures of BRD focus at the individual animal or herd level and include vaccination, mass treatment with antimicrobials and improvement of the animal's environment and general health status. Despite progress in our understanding of disease mechanism and technological development, the current preventive measures are not sufficiently effective. Thus, there is a need for alternative, sustainable strategies to combat the disease. Some of the primary infectious agents in the BRD complex are viruses that are easily transmitted between herds such as bovine respiratory syncytial virus (BRSV) and bovine coronavirus (BCoV). This conceptual analysis presents arguments for combatting BRD through improved external biosecurity in the cattle herds. As an example of a population-based approach to the control of BRD, the Norwegian BRSV/BCoV control-program is presented. The program is voluntary and launched by the national cattle industry. The core principle is classification of herds based on antibody testing and subsequent prevention of virus-introduction through improved biosecurity measures. Measures include external herd biosecurity barriers and regulations in the organization of animal trade to reduce direct and indirect transmission of virus. Improved biosecurity in a large proportion of herds will lead to a considerable effect at the population level. Positive herds are believed to gain freedom by time if new introduction is avoided. Vaccination is not used as part of the program. Dissemination of information to producers and veterinarians is essential. We believe that reducing the incidence of BRD in cattle is essential and will lead to reduced antimicrobial usage while at the same time improving animal health, welfare and production. Alternative approaches to the traditional control measures are needed

Using Biosecurity Measures to Combat Respiratory Disease in Cattle: The Norwegian Control Program for Bovine Respiratory Syncytial Virus and Bovine Coronavirus

Bovine respiratory disease (BRD) cause important health problems in all cattle husbandry systems. It contributes substantially to the use of antimicrobial substances and compromises animal welfare and the sustainability of the cattle industry. The existing preventive measures of BRD focus at the individual animal or herd level and include vaccination, mass treatment with antimicrobials and improvement of the animal’s environment and general health status. Despite progress in our understanding of disease mechanism and technological development, the current preventive measures are not sufficiently effective. Thus, there is a need for alternative, sustainable strategies to combat the disease. Some of the primary infectious agents in the BRD complex are viruses that are easily transmitted between herds such as bovine respiratory syncytial virus (BRSV) and bovine coronavirus (BCoV). This conceptual analysis presents arguments for combatting BRD through improved external biosecurity in the cattle herds. As an example of a population-based approach to the control of BRD, the Norwegian BRSV/BcoV control-program is presented. The program is voluntary and launched by the national cattle industry. The core principle is classification of herds based on antibody testing and subsequent prevention of virus-introduction through improved biosecurity measures. Measures include external herd biosecurity barriers and regulations in the organization of animal trade to reduce direct and indirect transmission of virus. Improved biosecurity in a large proportion of herds will lead to a considerable effect at the population level. Positive herds are believed to gain freedom by time if new introduction is avoided. Vaccination is not used as part of the program. Dissemination of information to producers and veterinarians is essential. We believe that reducing the incidence of BRD in cattle is essential and will lead to reduced antimicrobial usage while at the same time improving animal health, welfare and production. Alternative approaches to the traditional control measures are needed