A highly pathogenic avian influenza confirmed in four states can be very deadly for birds, but a Kansas State University poultry expert says humans do not need to worry about their own health or contaminated poultry products.

The US Department of Agriculture Animal and Plant Health Inspection Service has confirmed the presence of H5N2 avian influenza in Kansas, Missouri, Minnesota and Arkansas. This strain is considered highly pathogenic in birds with a high mortality rate.

The Centers for Disease Control considers the risk to people from these HPAI H5 infections in wild birds, backyard flocks and commercial poultry to be low. No human infections with the virus have been detected at this time.

Associate professor of animal sciences and industry and K-State Research and Extension state poultry specialist, Scott Beyer, said: "These H5N2 variants have never been known to cause any transmission between humans and poultry. We are always testing and monitoring to see if any birds have any type of influenza. We don't allow any infected birds to go to marketplace, which means the chance of them ever making it into the food supply is about zero."

Dr Beyer said influenza strains recombine, sometimes causing a more deadly, more transmissible flu like this H5N2. It is a strain that turkeys are highly susceptible to and is spreading through migration.

He added: "We think that birds migrating North and South are mixing together in certain zones, like nesting and feeding zones. If those birds stop and feed or nest for awhile, then move back to another area of the country, they can drop off the virus to our local small flocks and even our commercial farms. That's what we have started seeing."

To protect your flock, set up a perimeter or safe zone to keep your birds from outside fowl or other animals that could potentially spread the disease. Dr Beyer said other animals can spread this influenza, such as dogs and small birds.

He added: "For example, a visiting waterfowl drops feathers, which can be contaminated. A sparrow will grab the feather and make a nest in your facilities. The US doesn't allow any infected birds to go to marketplace, which means the chance of them ever making it into the food supply is about zero."

Infected birds show flu-like symptoms like coughing, sneezing, swelling around the eyes, flicking of the head and a raspy rattle sound when they breathe.