Do More To Control Avian Influenza in Asia, Industry Tells U.S.
GAINESVILLE, GA., November 30, 2005 - The United States should be doing more to control H5N1 highly pathogenic avian influenza in its current range in Asia to help reduce the chances of a human pandemic, an industry spokesman told federal officials at a special meeting November 30.
“More resources should be devoted to attempts to control the problem at the source, in the Asian poultry population,” Dr. John Smith, director of health services for Fieldale Farms Corporation, told the meeting. “Efforts to control and eliminate the avian form of the virus in domestic poultry in Asia, and to minimize the opportunities for human transfections, represent a more judicious application of resources compared to waiting for a human-adapted virus to emerge and then mounting a massive human pandemic response.”
Smith noted that controlling Asian bird flu in the village flocks of developing Asian nations is a “daunting challenge,” but said it was “no worse than the current prospects for confronting a massive human pandemic.”
Listening were Dr. Julie Gerberding, director of the U.S. Centers for Disease Control and Prevention, and Dr. John Clifford, chief veterinary medical officer of the USDA Animal & Plant Health Inspection Service (APHIS), as well as U.S. Representative Nathan Deal, Republican of Georgia, who arranged the session.
In comments to the media afterwards, Dr. Gerberding said the industry and government have experience in controlling AI outbreaks and would be able to handle one if it occurred.
“I’m impressed by the biosecurity protecting the poultry supply in this country,” she said. “If only all the other countries had these measures in place.”
Here are Dr. Smith comments in full:
Industry Perspective on the Asian Highly Pathogenic H5N1 Avian Influenza
Dr. John Smith, DVM, MS, MAM
Director of Health Services
Fieldale Farms Corporation, Baldwin, Georgia
A distinction should be made between the human disease and the avian disease. Currently, the Asian highly pathogenic H5N1 subtype of Avian Influenza (AI) (hereinafter referred as “Asian bird flu”) is an avian disease with sporadic human infections. While the possibility of adaptation of this virus for efficient human transmission is a grave concern, and while public health agencies need to be preparing for a possible human pandemic (whether with Asian bird flu or some other subtype), many in the industry feel that the media have overstated the current domestic threat, and we fear a public overreaction to future reports of any type of AI in birds of any sort. We do not mean to imply that reporting or discussion of this threat should be suppressed, only that the discussion should be based on science and reasonable probabilities, and reported in the proper context. More resources should be devoted to attempts to control the problem at the source, in the Asian poultry population. Efforts to control and eliminate the avian form of the virus in domestic poultry in Asia, and to minimize the opportunities for human transfections, represent a more judicious application of resources compared to waiting for a human-adapted virus to emerge and then mounting a massive human pandemic response. Controlling Asian bird flu in the village flocks of developing Asian nations is a daunting challenge, but certainly no worse than the current prospects for confronting a massive human pandemic.
The domestic commercial poultry industries, in partnership with our state departments of agriculture and the United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services (USDA APHIS VS), are well prepared to prevent, detect, and contain the threat of Asian bird flu, as well as other H5 and H7 subtypes, in our poultry populations. There are multiple layers of protection currently in place.
The Asian bird flu has never been detected in any sort of bird, wild or domestic, commercial or non-commercial, in the United States. Furthermore, infections with any H5 and H7 subtypes are very uncommon and are not tolerated in US commercial poultry. We hope to keep it that way. Wild waterfowl are the natural hosts for AI, and various subtypes, including H5 and H7, have always been found in those populations. Almost all birds in the US commercial poultry industries are raised in confinement in climate-controlled housing, and contact with wild waterfowl (or non-commercial poultry for that matter) is strictly prohibited. There is only minor overlap of the Asian and North American wild bird migratory flyways, and wild bird populations are being monitored for the Asian bird flu in Alaska. Detection of the Asian H5N1 subtype in North American waterfowl would lead to further precautions to prohibit any contact with commercial birds.
Infections with various subtypes of AI also occur sporadically in non-commercial and backyard flocks. AI, including a low pathogenic H7N2 strain, circulates in the live bird marketing systems of the northeastern United States. The commercial industry also makes efforts to isolate itself from these operations. USDA APHIS VS, in cooperation with the states and industry, has initiated an AI control program for the live bird marketing system. This program is reducing the incidence of AI in these systems, with the eventual goal of eradication.
The United States does not import poultry or poultry products from any regions affected by highly pathogenic AI. Inspections have always been in place at all international ports of entry to exclude products that might represent a disease threat to domestic agriculture. No live birds of any species from affected regions are permitted entry to the United States, and any live birds imported from disease-free regions are quarantined and tested to preclude the introduction of a foreign disease such as AI. While an introduction of the Asian bird flu virus into the commercial poultry of the United States is not impossible, the likelihood is currently very low.
In the unlikely event that an introduction were to occur, we are prepared to detect it quickly and respond rapidly. Our industries have biosecurity programs in place to prevent introductions of common domestic diseases. Growers are trained to restrict visitors, minimize their own contact with other birds and farms, use protective clothing, disinfect shared equipment, and so forth. These procedures will minimize the initial spread of any introduced foreign disease prior to detection.
Our commercial poultry populations have been actively monitored for the presence of AI for a number of years, to meet international trade requirements. Large numbers of broiler flocks have been tested for export to Mexico. A National Poultry Improvement Plan (NPIP) monitoring plan for breeder hens has been in existence for several years. This program is especially useful because breeders serve as a sensitive sentinel system, due to their long lives. A number of states, including Georgia, have separate breeder monitoring programs in addition to the NPIP program. These monitoring programs are now being intensified and expanded to commercial broiler, turkey, and layer flocks. In response to the low pathogenicity H7N2 AI outbreak in Virginia in 2002, the NPIP has developed an active and passive monitoring and containment program for commercial broilers, turkeys, and layers. This program is in the final stages of implementation, and many broiler producers are proceeding with implementation prior to inauguration of the official program. Most diagnostic laboratories have been testing flocks with any signs remotely suggestive of AI for the disease, and such passive monitoring programs are part of the proposed NPIP program. Finally, the signs of a disease such as the Asian bird flu are so dramatic that there is almost no possibility that it would go undetected in the integrated commercial system. The industry has conducted awareness programs for growers and industry supervisors and managers. Industry managers and veterinarians are cognizant of the steps necessary to quarantine suspect flocks and obtain a rapid diagnosis.
In the event of a case of any H5 or H7 subtype AI in broilers, the flock would be quarantined and destroyed on site. A low pathogenic outbreak is more likely than a highly pathogenic outbreak, but in either case the flock would be destroyed. Proven methods for accomplishing this unpleasant task in a humane, expeditious, environmentally sound, and safe manner are now in place in most major broiler producing areas. A quarantine zone around any infected flocks would be established and intensive monitoring begun. The most recent incursions, in Delmarva and Texas, were quickly detected and eliminated in this manner. Most areas are now prepared to respond even more quickly, and any outbreak in poultry would be rapidly contained. We have new information about protecting the workers that would be necessary to deal with the infected flocks. One advantage to the US commercial system is that relatively few people are exposed to the live birds during the production of tremendous amounts of poultry product, making the sorts of human infections seen in Asia even less likely. It is also highly unlikely that any infected birds would ever make it to slaughter, so exposure of processing plant workers or consumers to infected raw meat is unlikely. Finally, if some infected birds did manage to make it past all these hurdles, normal safe handling and cooking practices would effectively preclude a human infection among consumers.
In summary, the risk of an introduction of Asian bird flu into our commercial poultry is currently very low, and we are well prepared to detect and expeditiously handle any incursion that does occur. Finally, even in the event of an outbreak, the risks to the farmers, workers, and consumers in our system would remain minimal.