The Threat of Pandemic Influenza Are We Ready? Workshop Summary (2005) / Chapter Skim
Currently Skimming:
4 Strategies for Controlling Avian Influenza Birds and Mammals
4 Strategies for Controlling Avian Influenza Birds and Mammals
Pages 222-253
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 222... ...
This chapter focuses on the global phenomenon of avian influenza, its impact on the poultry industry, and potential means to control influenza transmission among birds and mammals. The chapter begins with a review of the activities of the Office International des Épizooties (OIE; also known as the World Organisation for Animal Health)
|
From page 223... ...
STANDARDS AND ACTIVITIES OF THE OIE RELATED TO AVIAN INFLUENZA Dewan Sibartie Scientific and Technical Department World Organisation for Animal Health (OIE) Introduction Preventing the spread of animal diseases and zoonoses through international trade is one of the primary objectives of the World Organisation for Animal Health (OIE)
|
From page 224... ...
· Promotion of the safety of world trade in animals and animal products The OIE develops standards for application by Member Countries to protect themselves against disease incursions as a result of trade in animals and animal products, while avoiding unjustified sanitary barriers. These standards are developed by experts from Member Countries and from the OIE's network of more than 160 Collabo rating Centers and Reference Laboratories.
|
From page 225... ...
Firmly convinced that the best way to reduce human exposure to the virus is to eliminate the virus at source -- that is, from animals, including wild birds -- the OIE strives to assist Member Countries in providing expertise particularly in the following areas: disease surveillance, early detection, early warning and notification, quality and evaluation of veterinary services, diagnosis, surveillance, control strategies, and international trade in poultry and poultry products. OIE Reference Laboratories and Experts The OIE is coordinating a worldwide network of some 150 Reference Laboratories and 13 Collaborating Centers and more than 300 experts in various animal diseases.
|
From page 226... ...
. The Terrestrial Code provides the governments and the Chief Veterinary Officers of OIE Member Countries with recommendations for establishing national health measures or rules applicable to the importation of animals and animal products with respect to OIE listed animal diseases in order to avoid importation of pathogens while avoiding unjustified sanitary barriers.
|
From page 227... ...
The results of this evaluation can help provide the importing country the assurance that information on sanitary/ zoosanitary situations provided by the veterinary services of an exporting country is objective, meaningful, and correct. Evaluation of veterinary services has gained further importance since the ban on imports of poultry and poultry products from several southeast Asian countries following the avian
|
From page 228... ...
As mentioned earlier, the OIE provides standards, guidelines and recommendations to assure the sanitary safety of international trade in animals and animal products to avoid the transfer of agents pathogenic for animals or humans while avoiding unjustified sanitary barriers. In this context, the OIE is fully aware of the constraints faced by countries wishing, for example, to export fresh poultry meat.
|
From page 229... ...
OIE has provided and will continue to provide expert assistance to southeast Asian countries to improve surveillance and monitoring systems to control the disease. The OIE advises that countries establish programs to monitor high-risk avian populations, such as live bird markets, fighting cocks, and other markets selling wild birds.
|
From page 230... ...
This has been particularly important during the recent influenza outbreaks in southeast Asia, when consumption of these commodities fell drastically, threatening millions of farmers who depend almost entirely on subsistence animal farming for their livelihoods. Therefore it was important to restore consumer confidence in poultry products.
|
From page 231... ...
· Isolation of virus from other wild birds is completely overshadowed by the number, variety, and distribution of influenza viruses isolated from waterfowl. The highest rate of detection of influenza virus is from ducks.
|
From page 232... ...
Control programs for virulent strains of avian influenza viruses therefore should be focused on biosecurity of poultry populations and protection of humans exposed to poultry. Continual OIE Involvement The OIE continues to monitor the worldwide AI situation closely, paying particular attention to southeast Asia, where the disease has far more economic and possibly more public health impact.
|
From page 233... ...
The primary risks for introduction into commercial poultry include: (1) direct access to wild birds infected with AI viruses, (2)
|
From page 234... ...
. The reservoir for genes of all type A influenza viruses circulate in wild bird populations, principally waterfowl (Order: Anseriformes)
|
From page 235... ...
, but a few have been HP, especially when isolated from wild birds trapped on poultry farms affected with HPAI. Common poultry species, including chickens and turkeys, are not natural hosts for avian influenza viruses (Hopkins et al., 1990; Suarez, 2000)
|
From page 236... ...
Turkeys are susceptible to swine influenza viruses, and having a turkey farm and swine farm in close proximity is a risk factor for the introduction of swine influenza to turkeys. Infections with both classical H1N1 swine influenza and the more recent reassortant H1N2 and H3N2 swine influenza viruses have been reported (Suarez et al., 2002; Wright et al., 1992)
|
From page 237... ...
Many live bird markets are never free of birds, and a continuous cycle of infection can be maintained, with the virus continuing to become better adapted to chickens. The virus in the live bird market system, although generally believed to be separate from our commercial poultry system, has been a nidus of infection for spread to our commercial poultry sector.
|
From page 238... ...
In a nationwide survey of commercial poultry through the National Poultry Improvement Plan in 1997 (Personal communication, Andy Rorer, National Poultry Improvement Plan, U.S. Department of Agriculture, April 28, 2001)
|
From page 239... ...
The live poultry market system continues to be a major source of AI viruses and risk for introduction to the commercial poultry operations. Avian Influenza Vaccines The AI vaccines provide protection from clinical signs and death, but protection is hemagglutinin subtype specific such that H5 AI vaccines only protect against the H5 subtype, and so on.
|
From page 240... ...
In 2001, 2,797,000 doses of H1N1 or H1N2 inactivated AI vaccine was used in turkey breeders to prevent infection by swine influenza viruses (Table 4-2) (Swayne, 2001)
|
From page 241... ...
Finally, the H5N1 HPAI viruses of Asia have been the primary focus as the next potential pandemic influenza viruses. However, we must remember that the previous three pandemics (1918, 1957, and 1968)
|
From page 242... ...
242 4 day ) on 7.2 Inoculation b taken Lung 0/2 0/2 0/2 2/2(10 were Isolation Intranasal )
|
From page 243... ...
The H6N2 low-pathogenicity strain of avian influenza virus, which infected commercial poultry in California, is not a strain regulated by either the California Department of Food and Agriculture (CDFA)
|
From page 244... ...
These dense populations, if infected with AI virus, can serve to exponentially expand the virus in a relatively small region, resulting in the infection of both commercial and noncommercial poultry. Concentrations of commercial poultry support the growth of population sectors, which in turn support animal agriculture.
|
From page 245... ...
. Both of these populations, the game fowl and the birds produced for live bird markets, have the potential to become reservoirs of virus for commercial poultry populations.
|
From page 246... ...
Scheduling should be done to avoid clean traffic 4. Manure should not be spread or stored close to any other poultry Marketing of eggs 1.
|
From page 247... ...
Increased mortality 3. Clinical signs of disease The next critical step is to determine what should happen with a positive flock.
|
From page 248... ...
Positive flocks (currently infected and shedding avian influenza virus)
|
From page 249... ...
Fulfill all CDFA/USDA requirements for biosecurity and flock plans Using this voluntary plan, California controlled and eradicated H6N2 AI virus from commercial poultry flocks. The producers in the state soon learned that not telling each other about AI virus infections resulted in the spread of the outbreak.
|
From page 250... ...
has raised the profile of live bird markets. Although surveillance has been increased, disease control measures have been established in only a few locations (Mullaney, 2003)
|
From page 251... ...
2000. Distinct pathogen esis of Hong Kong-origin H5N1 viruses in mice as compared to other highly pathogenic H5 avian influenza viruses.
|
From page 252... ...
2003. Sequence analysis of recent H7 avian influenza viruses associated with three different outbreaks in commercial poultry in the United States.
|
From page 253... ...
2003. Multiple genotypes of nonpathogenic H6N2 influenza viruses isolated from chick ens in California.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.