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Avian Influenza — What You Should Know
Avian influenza viruses, so called "bird flu," can be classified into low pathogenicity and high pathogenicity forms based on the severity of the illness they cause in poultry and waterfowl. Most avian influenza strains are classified as low pathogenic avian influenza and cause few or no clinical signs in infected birds. Low pathogenic avian influenza has been identified in the United States and around the world since the early 1900s. It is relatively common to detect low pathogenic viruses in wild waterfowl or shorebirds, which serve as the natural reservoir for this group of viruses. In contrast, high pathogenic avian influenza causes a severe and extremely contagious illness and death among infected birds. Avian influenza is primarily spread by direct contact between healthy birds and infected birds, and through indirect contact with contaminated equipment and materials. Waterfowl can introduce low pathogenic viruses into domestic poultry flocks raised on range or in open flight pens through fecal contamination.
Most avian influenza viruses found in birds do not represent a public health concern. Historically, high pathogenic avian influenza has seldom been found in U.S. poultry. Prior to 1997, it was generally believed that high pathogenic avian influenza did not spread directly from birds to people. However, since 1997, more than 120 people in other countries, primarily in the Far East, have died from a particular high pathogenic strain of avian influenza called H5N1. Most, if not all, became infected through direct contact with infected poultry. Broad concerns about public health relate to the potential for the virus to mutate, or change into a form that could easily spread from person to person, causing a pandemic. Because of this concern, the federal government and individual states, including Rhode Island, are preparing for the possibility of a flu pandemic. For HEALTH information on flu pandemic and the state's plans, click here.
There are several ways the high pathogenic H5N1 could enter the United States: through poultry, illegal trade of poultry product, migratory birds, and/or on the shoes of humans. The US Department of Agriculture and the US Fish and Wildlife Service, in cooperation with states, including Rhode Island, are engaged in targeted and passive surveillance of waterfowl and poultry, information sharing, and outreach to producers regarding the need for effective on-farm biosecurity practices, and other measures.
Rhode Island is participating in a nationwide effort of surveillance of wild birds for avian influenza, particularly high pathogenic H5N1, since the migration of waterfowl presents a very real possibility for carrying the avian influenza virus from country to country. Staff from DEM's Division of Fish and Wildlife plan to sample a number of resident geese and migratory waterfowl.
Staff from DEM's Division of Agriculture are working with farmers, back yard poultry breeders, and other affected groups, to educate them on practicing biosecurity for their flocks, and have implemented a poultry-monitoring program for avian influenza. They are promoting the US Department of Agriculture's 'Biosecurity for the Birds' program, which is designed to educate non-commercial poultry owners about the signs of avian influenza and other poultry diseases. It promotes the importance of practicing biosecurity, and encourages rapid reporting of clinical signs of disease and/or unexpected deaths. For information on Biosecurity for the Birds, click here.
In the event of a high pathogenic avian influenza outbreak in poultry, affected flocks would be quickly quarantined to prevent spread. Sick and exposed birds would be euthanized and the premises cleaned and disinfected to stamp out the disease. The US Department of Agriculture and DEM would conduct investigations to determine the source of the virus, and to track the movement of birds to contain spread of the disease. Immediately upon the establishment of an infected zone, an active surveillance program would determine if the disease might be present in susceptible wild bird populations within the zone.