Tests rule out Asian bird flu in Michigan swans

Libby Quaid / Associated Press

WASHINGTON -- Bird flu found in a wild swan in Michigan was not the deadly Asian strain that has ravaged poultry and killed at least 141 people worldwide, the Agriculture Department said Monday.

Final tests confirmed the swan had a mostly harmless, low-pathogenic strain of the H5N1 virus, officials said.

Authorities found bird flu Aug. 14 in two mute swans on the shore of Lake Erie in Monroe County, Mich., but only one of the samples had high enough levels of flu to allow confirmatory tests. Earlier genetic analysis ruled out the more virulent Asian strain in both birds.

The low-grade strain has been found many times in North American wild birds and poses no threat to people, the department said. Confirmatory tests were done by the department's National Veterinary Services Laboratories in Ames, Iowa.

The swans were the first reported in the government's effort to test as many as 100,000 wild birds to determine if the virulent Asian H5N1 strain has arrived in North America. Officials expect the virus to reach the continent this year.

The sampling was expanded earlier this month from Alaska to the entire nation. Among the first targets were 20 mute swans from a game area in Monroe County. Testing found the possibility of H5N1 in two of the swans.

Any finding of highly pathogenic H5N1 in wild birds in the U.S. would prompt more intensive monitoring and extra security measures to protect commercial poultry flocks from infection.

Deadly, highly pathogenic strains spread rapidly and are usually fatal to chickens and turkeys, the department said, while low pathogenic H5N1 generally causes little sign of sickness in birds.

Since 2003, the virulent H5N1 strain has been blamed for the death or destruction of millions of birds overseas. Nearly all the people who have been infected had close contact with sick birds or their droppings. However, scientists fear the virus could mutate into a form that is spread easily among humans.

When Dr. Dale Fay, then veterinarian-in-charge, moved the former Game Division Laboratory from Michigan State University to the Rose Lake Wildlife Experiment Station in 1957, the lab was set up in a barn.

Last August, Dr. Stephen Schmitt and his colleagues at the Department of Natural Resources Wildlife Disease Lab moved back to MSU, but this time it was into a brand new $58 million, 152,500-square-foot, state-of-the-art facility that is shared with the College of Veterinary Medicine's Diagnostic Center for Population and Animal Health.

"The new facility is just awesome," Schmitt said. "It houses 11 different laboratories dealing with animal disease--domestic and wild--under one roof. When we can work shoulder to shoulder with the top scientists who keep a finger on the pulse of the animal disease situation in this state, we have the opportunity to discuss research and collaborate, which helps foster new ideas."

The DNR has a long history of involvement with health concerns of wildlife, and the relationship between wildlife and livestock disease.

Nearly a half-century ago, the old Game Division lab was beginning a two-year survey to determine the status of brucellosis, a disease that affects domestic livestock, in Michigan's wild deer. More than 1,200 deer were tested and all were free of brucellosis, indicating this disease was not a problem for deer.

However, since 1995, DNR scientists and state health officials have tested more than 130,000 deer as part of Michigan's strategy to eliminate bovine tuberculosis in deer and elk and are conducting surveillance for diseases that have yet to be found in Michigan such as chronic wasting disease, which has hit a number of states, including nearby Wisconsin.

"The new facility provides more space; a safe, secure, modern working environment and the ability to more efficiently handle the large volume of deer heads that are brought here from all over the state each fall," Schmitt said.

Using the latest, most effective and best available technology to provide cutting-edge services in clinical pathology, parasitology, bacteriology, toxicology and virology, the diagnostic center is the state's first line of defense in the identification of emerging diseases that threaten animal and human health, such as West Nile virus, Salmonella, Lyme disease and rabies, including a new strain of raccoon rabies that has been found along the Eastern Seaboard of the United States.

"Emerging diseases that may be transmitted between animals and humans are a concern for all people, no matter what their age, gender, lifestyle, ethnic background or economic status," said center director Willie Reed. "Our lab is set up to handle a problem that could come 10 years down the road. We can do tests for any organism in any animal. No one else is able to do that."

Approximately 10 percent of the facility, which is owned and operated by MSU, is occupied by the DNR. In addition to the scientists and technicians working specifically on wildlife disease issues, other lab personnel work full-time in support of DNR wildlife population management and law enforcement programs.

To assist department law officials in gathering evidence in poaching-related cases, the lab can run a number of wildlife forensic procedures, including x-ray and a complete necropsy to determine cause of death and the caliber of the gun used to kill the animal.

They also conduct a variety of population biometry surveys for bear, elk and furbearing animals.

To assist biologists in managing Michigan's black bear population, for example, the lab can conduct a test to identify a tetracycline biomarker in a bear's tooth or run a DNA analysis of a bear's hair sample. Both are used to estimate population size.

Counting the cementum annuli (dark stain lines) in tooth sections is a frequent diagnostic tool used by scientists to determine the ages of bear, elk, bobcat and other animals, and using tooth measurements and DNA analysis of feathers and tissues, scientists also can determine the sex of wildlife.

In the lab, DNR personnel also routinely conduct bone marrow fat analysis to determine the nutritional status of moose, elk and deer. In the future, more scientific information will be gained through DNA analysis.

"Globalization has brought a host of foreign species and diseases to Michigan, and this diagnostic center is a vital key in our continued efforts to ensure the health of Michigan's wildlife," said DNR Director Rebecca Humphries. "We're especially pleased to be working with MSU and the state Department of Agriculture in a partnership that will undoubtedly help secure a safe, healthy future for our wildlife resources."