Federal and state agencies plan to conduct research into the possible spread of bird flu in the respiratory tract among dairy cows, according to a Reuters interview with Michigan agriculture and public health officials.
Scientists and government officials hope the research will guide efforts to contain the virus and reduce human exposure to it. They said that the spread of the virus through the respiratory system may give it a greater opportunity to develop.
So far, it is suspected that the virus will spread between animals and humans through exposure to contaminated milk, aerosolized milk droplets, or through exposure to infected birds or poultry.
Tim Boring, director of the Michigan Department of Agriculture and Rural Development, said the department is working with the state university and the Department of Agriculture to plan on-farm research to assess respiratory spread of the virus.
He added, “This is an important matter that we are working on building and researching further.” He said that the research represents a top priority and will be important for directing the state’s public policy.
A Ministry of Agriculture spokesman noted that research on respiratory infections in dairy cows is being conducted with partners including universities across the country, to better understand the virus and control its spread.
Bird influenza infections have been detected in more than 80 herds of dairy cows in 11 states since late March.
Micro mechanisms
The exact mechanisms of spread of the virus remain unclear, although there is evidence of transmission to cattle from wild birds and other cattle.
Zelmar Rodriguez, a dairy veterinarian and assistant professor at the University of Michigan College of Veterinary Medicine, who conducted research on affected farms, said the virus was detected mainly in milk, but also in nasal swabs at lower levels.
He added, “If it is present in the nose when the cow excretes (the virus), it is likely to be transmitted through the air.”
For his part, Richard Wiebe, a virologist at St. Jude Children’s Research Hospital – who studies influenza in animals and birds for the World Health Organization – said that any change in how the virus is transmitted gives it the opportunity to evolve.