WASHINGTON, Sept. 1, 2006 — The U.S. Departments of Agriculture and Interior today announced that the presence of the H5N1 avian influenza subtype has been detected in fecal samples from wild birds in Maryland. Testing has ruled out the possibility of this being the highly pathogenic H5N1 strain that has spread through birds in Asia, Europe and Africa. Test results thus far indicate this is low pathogenic avian influenza (LPAI), which poses no threat to human health.
The fecal samples were collected on August 2 from resident wild ducks in Queen Anne’s County, Maryland, as part of a research project conducted by Ohio State University. The fecal samples came from mallards that showed no signs of sickness, which also suggests that this is LPAI.
Because of the nature of the research project and because there was no sign of illness in the birds, the samples were not prioritized for testing. On August 24, 2006, USDA’s National Veterinary Services Laboratories (NVSL) in Ames, Iowa received the samples. On August 31, 2006, NVSL tests indicated that nine samples were positive for the H5N1 avian influenza subtype. Today, genetic analysis of the virus was completed, which suggests that this virus is similar to low pathogenic strains that have been found previously in North America.
LPAI commonly occurs in wild birds, where it typically causes only minor symptoms or no noticeable symptoms. These strains of the virus are not a human health concern. This includes LPAI H5N1, commonly referred to as North American H5N1. This strain of LPAI is very different from the more severe HPAI H5N1 circulating overseas, which is commonly referred to as the Asian H5N1.
Additional testing at NVSL will confirm the pathogenicity of the virus. These results are expected within two weeks and will be made public when completed. It should be noted that wild birds are known to harbor many influenza viruses, and the finding of these viruses during routine testing is not unusual.
Recognizing that LPAI is endemic in wild bird populations, commercial poultry operators, including those in Maryland, employ extensive biosecurity measures to prevent exposure to wild birds and have done so for more than ten years. According to guidelines issued by the World Organization for Animal Health, known as OIE, there should be no trade restrictions imposed due to detection of avian influenza in wild birds.
Mallard ducks are among the wild bird populations that are commonly hunted. 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.
Numerous institutions of higher learning collaborate with USDA to conduct avian influenza testing. USDA issues grants to researchers, who voluntarily submit for testing the samples they collect from birds. This research-related testing compliments the extensive wild bird testing program implemented jointly by DOI and USDA in April 2006.
For more information about USDA’s efforts and research related to avian influenza, go to www.usda.gov/birdflu. For more information about DOI’s efforts and hunter education program, go to www.doi.gov/issues/avianflu.html. For information about the federal government’s overall efforts related to avian influenza and human pandemic preparations, go to www.avianflu.gov.