USDA looks to stem H5N1

Worldwide, there are many strains of avian influenza (AI) virus, which can cause varying degrees of illness in poultry. Al viruses can infect chickens, turkeys, quail, ducks, geese, pheasants, and guinea fowl as well as a wide variety of other birds. Migratory waterfowl also are known to carry the less infectious strains of Al viruses. Each year, there is a flu season for birds just as there is for humans and, as with people, some forms are worse than others.

AI strains are divided into two groups: low pathogenicity (LP) and high pathogenicity (HP). LPAI, or "low path" avian influenza, has existed in the U.S. since the early 1900s. It causes birds to become ill and can be fatal to them. These strains pose no known serious threat to human health. HPAI, or "high path" avian influenza, is more fatal and transmissible. HPAI is the type currently affecting parts of Asia and Eastern Europe. These strains have been transmitted from birds to humans, most of whom had extensive, direct contact with infected fowl. HPAI has been detected three times in the U.S.: 1924, 1983, and 2004.

The Department of Agriculture's Animal and Plant Health Inspection Service works with states to monitor and respond to outbreaks of LPAI. APHIS provides funds and support personnel to states when LPAI is detected. When HPAI is detected, APHIS personnel are primary responders, due to its infectivity and high mortality rate among poultry. Close attention also is given to two subtypes of LPAI, the H5 and H7 strains, because of the potential for them to mutate in HPAI. The Al strain infecting both birds and humans in Asia is HPAI H5N1. There presently is no evidence of it existing in the U.S.--in animals or humans.

To encourage producers to report sick birds, APHIS conducts an outreach campaign called "Biosecurity for the Birds." It provides poultry producers with the latest information on biosecurity, in several languages, to prevent the spread of this disease on the farm. Additional surveillance efforts specifically target live bird markets. The USDA works closely with the industry to test commercial flocks randomly as well as testing birds that show signs of illness. Scientists also have been testing wild migratory birds since 1998 in the Alaska flyway.

As a primary safeguard against the reintroduction of HPAI into the U.S., APHIS maintains trade restrictions on the importation of pet birds, poultry, and poultry products from Al-H5Nl-affected countries. Additionally, all birds, including pets, brought into the U.S. from regions experiencing Al or other diseases of concern are quarantined and tested at an APHIS Animal Import Center for 30 days.

In 2002, the USDA Agricultural Research Service (ARS) developed a rapid diagnostic test for avian influenza, which diagnoses the malady within three hours, compared with up to two weeks required for previous tests. The rapid diagnostics were used in the eradication of avian influenza in Texas in 2004. The test has been distributed to the National Animal Health Laboratory Network, which includes university and state veterinary labs throughout the U.S.

Moreover, APHIS maintains an Al vaccine supply for poultry that can be used to create a buffer around an identified area, in the event of a large outbreak among poultry, to contain the disease while it is in the process of being eradicated. In addition, the agency has formed a national network of personnel to assist with surveillance and response in the event of an outbreak of HPAI or other foreign animal disease. That network includes more than 40,000 accredited private veterinarians who report any suspected disease outbreak to Federal or state officials.

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