Bird flu has spread to dairy cows

Avian influenza, which wild birds have been transmitting to poultry during the last two years, has now spread to dairy cows, State Epidemiologist Dr. Cherie Drenzek reported this week.

Cows in 40 dairy herds in nine states – but not Georgia – started coming down with the H5N1 strain of bird flu in March, Drenzek told members of the state Board of Public Health. The outbreak began in Texas last December, she said.

Thus far, the only human infected with the virus was a dairy farm worker in Colorado, Drenzek said.

'The human health risk remains low for the general public,' she said.

While H5N1 manifests in poultry as a severe respiratory infection, it tends to be mild in dairy cows, Drenzek said. However, it can be spread in raw milk, she said. 'H5N1 is killed by pasteurization,' she said.

As a result, the state Department of Public Health is monitoring both dairy and poultry farmworkers in Georgia for the virus, Drenzek said.

Two outbreaks of avian influenza occurred in Georgia two years ago, both in backyard poultry flocks. While 117 people were exposed, none came down with the virus, Drenzek said.