H5N1 spread challenges farm biosecurity

As the United States continues to deal with the spread of avian influenza, challenges to prevention are wildlife, environment, fomite transfer and flock additions.

Illinois State Veterinarian Mark Ernst spoke during a University of Illinois farmdoc daily webinar Feb. 25.

There is no way to control waterfowl migration, he said.

“Mortality in wild waterfowl is variable — some species of ducks and geese can harbor the disease in a carrier state and then the carrier birds can spread the virus through their droppings and other methods,” Ernst said.

Prevention solutions for wildlife include sealing entry points to a building and keeping the area around it clean and free of loose feed.

Waterfowl hazing strategies include auditory devices, visual scaring devices and grid wiring over desired exclusion areas like ponds.

The environment is a challenge because virus survival varies. It can survive for eight weeks at 39 degrees Fahrenheit in wet or dry droppings, 30 days on feathers, one to 14 days in soil, 26 hours on plastic, 4.5 hours on skin, 24-28 hours on metal and two weeks on wood.

Unless a surface has been disinfected, it should be considered contaminated, Ernst said.

Fomite transfer involves clothing, footwear and equipment used outside the poultry operations. Prevention solutions for the environment and fomites include sanitation through continuous cleaning and disinfection of equipment, clothing and footwear. Producers should restrict visitors and restrict employees from owning their own poultry, Ernst said.

Restricting vehicle traffic to designated areas and disinfection of tires and undercarriage of vehicles should be done upon entry and exit from the flock. Only dedicated equipment should be used in the facility, and it should be disinfected often. Dedicated clothing and footwear should be required, he said.

Adding new birds to a flock can have a number of risks.

When it comes to flock additions, this should be done by single source, and isolation of incoming birds should be utilized with an all-in/all-out procedure that involves cleaning and disinfection before restocking, Ernst said.