BATON ROUGE -- Researchers at Louisiana State University have discovered that a bovine virus not previously believed to cause respiratory-tract infections in cattle is associated with several outbreaks of shipping-fever pneumonia, the most fatal form of bovine respiratory-tract disease. The virus has been detected among cattle in 11 different states in the southern and western United States.
The respiratory bovine coronavirus had not been considered a factor in shipping-fever pneumonia prior to this discovery, said Dr. Johannes Storz of the LSU School of Veterinary Medicine. The research findings could also lead to a vaccine for the coronavirus, Storz said.
"Shipping fever results from the stress of transporting cattle, which favors viral and bacterial infections of the respiratory tracts," said Storz, professor of veterinary microbiology and former head of the Department of Veterinary Microbiology and Parasitology at the Vet School. Approximately 90 percent of cattle involved in two major U.S. outbreaks of shipping-fever pneumonia were infected with the coronavirus, Storz said.
Storz and his research team at LSU employed a novel technology for cultivating viruses from respiratory-tract samples from cattle. This new method involved the use of specific clones of cultured animal cells. Once the samples from the cattle were applied to the cloned cell cultures, Storz observed the coronavirus.
The respiratory coronavirus infects cells that line the upper and lower respiratory tracts, including the lungs. Storz said the coronavirus kills the cells and causes inflammation in the mucous-membrane passages of the respiratory tract. "Ultimately, these infections interfere with the cells' normal function in the respiratory tract," Storz said.
Infectious diseases are a continuous threat to humans and animals alike. This fact is evident by the recent outbreak of foot-and-mouth disease in Europe. Storz and his research team at LSU are fighting against outbreaks by exploring the possible causes of these diseases.
"We need to be constantly aware of potential emerging infectious diseases and the possible spread of known infectious diseases," Storz said.
Infectious diseases also have a huge economic impact on the beef and dairy industries. According to the U.S. Department of Agriculture, the cattle industry suffered a $450 million loss in 1996 due to respiratory-tract diseases alone.
Storz's research has led to several advancements in the study of respiratory-tract diseases. He and his team have developed new techniques and specific diagnostic tests that detect viral infections in cattle. His research has also defined the components of the respiratory coronavirus, a process that is necessary to produce an effective vaccine.
This research advance was accomplished in cooperation with scientists from the LSU Agricultural Center, the College of Veterinary Medicine at Texas A&M University and the Agricultural Research Service division of the U.S. Department of Agriculture.
The research was made possible through funds from the LSU School of Veterinary Medicine, the Louisiana Education Quality Support Fund, industrial companies such as Immtech Biologicals and the Bayer Corporation, the Louisiana Beef Industry Council and the U.S. Department of Agriculture. Storz and his research team have been invited to present their findings at both national and international conventions. The most recent is an invitation to present a lecture at the 2002 World Congress on Diseases of Cattle in Hannover, Germany. "We are delighted about the opportunity to share our discoveries with veterinarians and scientists of international organizations," Storz said.
Materials provided by Louisiana State University. Note: Content may be edited for style and length.
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