Surveillance for avian influenza in the United States

Abstract

In the United States, some 1.7 million agar gel immuno diffusion (AGID) tests for avian influenza (AI) are conducted yearly by various poultry groups, governmental sectors, and private industry. In addition to the AGID test, additional testing includes virus isolations, enzyme-linked immunosorbent assays, real-time reverse transcriptase polymerase chain reactions, and hemagglutination inhibition (HI) tests. HI and neuraminidase inhibition tests are conducted on positive AGID samples to determine the subtype. Directigen, a type of antigen capture test, is used in the field in some cases. If monitoring and surveillance activities give rise to a suspicious test result, the accredited veterinarian and official State laboratory are required to report these to the governmental authorities. A thorough investigation in collaboration with the National Veterinary Services Laboratories (a World Organization for Animal Health--AI reference laboratory), State and Federal veterinarians, and others is conducted. Testing conducted as part of the National Poultry Improvement Plan (NPIP) effectively monitors the status of breeder and multiplier flocks. A new commercial poultry program is being added and will expand NPIP AI testing to all commercial flocks. Private poultry companies conduct additional tests; and in the poultry-producing States, there are active state-wide programs to monitor poultry health. All components of the live-bird market system (source flocks, haulers, dealers, and markets) are tested under the Low Pathogenicity AI Live-Bird Market Program.