MANHATTAN, Kan. -- Amid high gas prices, kids returning to school and terrorist threats, avian flu may not be foremost on the minds of most Americans, but Kansas State University scientists are keeping a watchful eye on developments of the virus.

While birds and in some cases humans have contracted the disease in Asia, Africa and Europe, no birds or humans have tested positive for the high-pathogenic form of avian influenza H5N1 in North America to date, said Kansas State University Research and Extension veterinarian Larry Hollis.

"Many scientists who are following this believe it's likely that the higher pathogenic strain could arrive in North America and the High Plains late this summer or fall," Hollis said.

They expect the virus will arrive in migrating birds from countries where untold numbers of birds have died naturally or have been destroyed because of the virus.

The USDA has been testing birds near the Arctic Circle this summer, with no positive nesting or migrating birds detected. As the southern migration began, the USDA in cooperation with state agencies announced in mid-August that it it has expanded its surveillance program of wild birds into the lower 48 states.

Two mute swans in Michigan this summer were found to have a lower-pathogenic form of the H5 and N1 viruses that previously have existed in the United States. This form has not been associated with any recent bird deaths or human health problems.

Avian influenza in general is not new to birds or the poultry industry, Hollis said. The U.S. government and commercial poultry industry have had controls in place for years to make sure that birds infected with any influenza strain do not reach consumers.

"It's also important to keep in mind that the current strain of avian flu (H5N1) that people are concerned with is transmitted primarily between bird species," Hollis said.

Since 2003, however, the World Health Organization has reported 241 cases of humans infected by the H5N1 virus worldwide. Of those infected, 141 have died, according to the U.S. government Web site devoted to the subject. So far, most human infections have resulted from direct contact with infected birds.

Scientists are concerned that if the H5N1 virus develops the ability to transfer easily between humans, it could spread quickly around the world, potentially causing a human influenza pandemic.

Because wild bird migratory patterns suggest that avian flu will reach the United States and the Great Plains this fall, anyone with chickens, ducks or other backyard birds should familiarize themselves with the symptoms of avian flu and be prepared to contact their veterinarian or Kansas Animal Health Department personnel, Hollis said. That also holds true for larger-scale poultry producers.

In addition to the Web site, information about avian flu and its possible effect on birds and humans is available at county and district K-State Research and Extension offices and on avian-flu-specific Web sites from the National Wildlife Health Center; the Kansas Department of Health and Environment and K-State Research and Extension.

SOURCE: K-State Research and Extension news release.