|By JANE HOUIN
WASHINGTON, D.C. — The USDA and the U.S. Department of Interior confirmed last week that final test results from the USDA National Veterinary Services Laboratories (NVSL) indicate avian influenza virus was not present in samples collected in October from wild Northern pintail ducks in Ottawa County, Ohio.
Initial screening results announced on Oct. 14 indicated that H5 and N1 subtypes might be present in the collected samples, but further testing was necessary to confirm the H and N subtypes as well as pathogenicity.
Avian influenza is a virus that can cause a varying amount of disease among birds, including chickens, turkeys, pheasants, quail, geese and ducks as well as a variety of other birds. Virus strains can be either low or high pathogenic, based on the severity of the illness they cause in poultry.
The initial rapid screening tests are highly sensitive and can detect inactive viruses in samples. It is not unexpected to have positive results on an initial screening test and then to have confirmatory testing reveal that no active virus is present in a sample. The initial screening tests performed on the Ohio samples resulted in a weak positive for both H5 and N1. During confirmatory testing, H5 and N1 subtypes were not found; no virus could be grown during the virus isolation test.
The bird samples were collected on Oct. 8 through a partnership between USDA and the Ohio Division of Wildlife as part of an expanded wild bird monitoring program, part of the $91 million appropriated in the Emergency Supplemental Appropriation to Address Pandemic Influenza in February. USDA and DOI are working collaboratively with states to sample wild birds throughout the U.S. for the presence of highly pathogenic avian influenza (HPAI). As a result of expanded testing, USDA and DOI expect to identify additional cases of common strains of avian influenza in birds, which is not cause for concern.
Low pathogenic avian influenza commonly occurs in wild birds. It typically causes only minor sickness or no noticeable symptoms in birds. These strains of the virus include LPAI H5N1, commonly referred to as “North American” H5N1, which is very different from the more severe HPAI H5N1 circulating overseas.
There is no known health risk to hunters or hunting dogs from contact with low pathogenic forms of avian influenza virus. Nevertheless, hunters are always encouraged to use common sense sanitation practices, such as hand washing and thorough cooking, when handling or preparing wildlife of any kind. DOI has issued guidelines for safe handling and preparation of wild game.
Low-path avian influenza viruses have been found for decades and are most often found in migratory waterfowl, such as ducks, geese and swans. Susceptible birds can become infected with avian influenza virus when they have contact with nasal secretions of fecal material from infected birds of with areas contaminated by them.
The occurrence of low-path strains in wild birds is seasonal, with the highest rate of infection typically occurring in late summer in juvenile waterfowl when they assemble for their first southward migration. The number then decreases in the fall as the birds migrate south to their wintering grounds.
To date, USDA and DOI have announced 12 presumptive positive and/or confirmatory test results in six states (Michigan, Maryland, Pennsylva-nia, Montana, Illinois and Ohio). As the expanded surveillance of wild birds for highly pathogenic avian influenza increases in the coming months, USDA and DOI expect additional detections of the “North American strain” of low pathogenic H5N1 avian influenza (LPAI H5N1).
Because these LPAI H5N1 detections are common and pose no threat to human health, USDA and DOI are transitioning to a new method of notifying the public.
In an effort to maintain transparency, USDA and DOI will post all future suspected LPAI H5N1 detections on the Internet. DOI will maintain a list of all such routine detections as part of the National Highly Pathogenic Avian Influenza Early Detection Data System (HEDDS).
The low path H5N1 detection list is at http://wildlifedisease.nbii.gov/ai/LPAITable.pdf
A link is available on the USDA’s avian influenza website at www.usda.gov/birdflu
In the event of a presumptive H5N1 test result involving a large number of sick or dead birds, or other circumstances that suggest the possibility of a highly pathogenic virus, USDA and DOI will issue a news release or conduct a technical briefing to notify the media and the public.
USDA also continues to strengthen safeguards already in place to protect against the introduction of HPAI H5N1 into the United States.
For example, USDA maintains trade restrictions on the importation of poultry and poultry products from regions currently affected by H5N1 HPAI in commercial or traditionally raised flocks.
Additionally, USDA and state animal health officials are working cooperatively with the poultry industry to conduct surveillance at breeding flocks, slaughter plants, live-bird markets, livestock auctions and poultry dealers.
“We must continue to prepare all levels of government to respond effectively if a pandemic occurs,” said Gov. Bob Taft. “Ohio’s comprehensive pandemic flu planning effort will integrate strategies at various levels of government, coordinate activities across all sectors of health care, emergency response and homeland security, and provide Ohioans the information they need to protect themselves and their families.”
The Ohio Department of Agriculture’s Division of Animal Industry has provided surveillance for avian influenza on commercial poultry populations for more than 20 years, with current efforts including surveillance testing of commercial poultry from collected blood samples.
Ohio has participated in several pandemic flu preparation activities, including pandemic flu exercises in April and June as well as a planning summit in February hosted by U.S. Health and Human Services Secretary Mike Leavitt. The summit convened more than 500 health, emergency management, agriculture, business and community leaders representing all parts of Ohio.
USDA has also implemented a reporting system to answer calls and inquiries from the public regarding dead or sick wild birds. The toll-free number, 866-4 USDAWS, is for public inquiries and to help expedite calls.
For details on collaborative avian influenza efforts go to www.doi.gov/issues/avianflu or the U.S. Govern-ment’s website for avian influenza and human pandemic preparedness at www.avianflu.gov
This farm news was published in the Nov. 8, 2006 issue of Farm World, serving Indiana, Ohio, Illinois, Kentucky, Michigan and Tennessee.