US - The US Department of Agriculture's Animal and Plant Health Inspection Service (USDA-APHIS) has published updated plans for surveillance of avian influenza in wild birds, which provide for an increase in sampling.
The 'interagency' strategies aim to help with preparation for possible future outbreaks of avian flu, by increasing monitoring of wild birds during their autumn migration south.
Between now and March 2016, avian flu surveillance in wild birds will intensify as APHIS Wildlife Services biologists and their State partners collect approximately 41,000 samples from apparently healthy wild birds from targeted areas throughout the United States.
The first updated plan describes a unified national system for migratory wild bird sampling involving Federal, State, university and non-governmental organisations, whilst the second updated plan outlines specific wild bird surveillance efforts for 2015-2016.
“The early detection of avian influenza remains key to controlling its spread and minimising its effects,” said Dr John Clifford, USDA chief veterinary officer.
“Many of the activities outlined in these plans are already being implemented and help warn us of any re-assortments or changes in low or highly pathogenic avian influenza viruses in wild birds which could be detrimental to our domestic flocks.”
Samples will be collected primarily from live-captured and hunter-harvested dabbling ducks, such as American black duck, American green-winged teal, mallard and Northern pintail. Additionally, environmental fecal samples from waterfowl and samples from morbidity and mortality events of all wild bird species also will be collected.
Results from the surveillance effort will be incorporated into national risk assessments as well as preparedness and response planning efforts so that avian flu risks are reduced in commercial poultry, backyard poultry, game bird farms, wild birds, wild bird rehabilitation facilities, falconry birds, and captive bird collections in zoos/aviaries.
Avian influenza viruses can be classified as highly pathogenic avian influenza (HPAI) or low pathogenic (LPAI) strains based on the severity of the illness they cause.
LPAI typically causes only minor illness, and sometimes manifests no clinical signs. However, some LPAI virus strains are capable of mutating under field conditions into HPAI viruses.
Wild birds can shed both LPAI and HPAI virus into the environment through their oral and nasal secretions and faeces. Once in the environment, these viruses can infect backyard poultry through the environment or through direct contact with infected wild birds.
Through breeches in biosecurity, HPAI viruses also can move from the environment into poultry facilities.
Since December 2014, the USDA has confirmed cases of HPAI H5 in the Pacific, Central and Mississippi flyways (or migratory bird paths). The disease has been found in wild birds, as well as in more than 200 backyard and commercial poultry flocks.
While wild dabbling ducks appear to have no ill effects from the virus, HPAI H5 is lethal to raptors and its impacts on other wild birds are unknown. HPAI H5 can cause severe disease and death in domestic birds.
The US' Centre for Disease Control (CDC) considers the risk to people from these HPAI H5 infections to be low. No human cases of these HPAI H5 viruses have been detected in the United States, Canada, or internationally.
As USDA and its Federal, State and industry partners continue to respond to this current outbreak, all continue to stress the importance of enhanced biosecurity measures for backyard and commercial poultry owners.
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