assessment for contracting highly pathogenic avian influenza from
eating poultry products, shell eggs and egg products
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[December 05, 2008]
The U.S. Department of Agriculture
released a draft this week of its risk assessment for contracting
highly pathogenic avian influenza from eating poultry products,
shell eggs and egg products, a tool that could be used to reduce
human illness from the virus and help target messages to consumers.
In releasing the risk-assessment draft, the USDA's Food Safety
and Inspection Service, known as FSIS, said it was seeking public
comments, which are due by Jan 31. The 186-page
report and information on how to submit
comments are available online from the FSIS.
The draft risk assessment, which addresses highly pathogenic H5 and
H7 subtypes, was developed by representatives from the FSIS, the
USDA's Animal and Plant Health Inspection Service, and the Food and
Drug Administration, according to a press release this week from the
USDA. The document went through an external peer review, along with
reviews by other government agencies, the USDA said.
So far there has been no compelling evidence that links eating
cooked poultry, eggs or egg products to avian influenza infections
in humans, the draft report said. Though the viruses aren't
considered foodborne pathogens, researchers have isolated them from
poultry muscle and egg interiors.
Two human illnesses may have been related to consuming infected
duck blood products, though investigators could not rule out contact
that the patients may have had with infected poultry. Despite this
lack of evidence, human exposure to contaminated poultry and eggs is
a concern for food safety experts, the report said.
Experts used available information on avian influenza viruses and
mathematical modeling to make risk estimates for several poultry and
egg scenarios, including production, processing and consumer
preparation. For example, the estimates assume that the viral load
in a serving of poultry relates to the time between when the bird
was infected and when it was slaughtered.
According to some of the scenarios,
the draft risk assessment for poultry meat predicts that:
infected early in their growing period are likely -- 94 percent
for chicken and 98 percent for turkey -- to be identified as
positive for the virus before slaughter, processing and sale.
approaching market weight present a small risk of infected meat
reaching commerce -- 6 percent for chicken and 2 percent for
turkey -- because there is less time for bird deaths to be
detected on the farm.
influenza testing offers the greatest chance for curbing human
infections; 95 percent can be prevented when birds are tested
mortality observations on the farm and after transport isn't as
practical, especially if birds are late in the grow-out period.
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Cooking poultry to
the FSIS-recommended temperature of 165 degrees F inactivates
the virus, lowering the public health risk to a negligible
Cross-contamination from infected poultry to uncooked foods
could increase illness levels by 2.5 percent, and public health
messages should emphasize this food-handling risk.
Regarding eggs and egg products, the USDA's risk assessment
predicts that nearly all contaminated eggs from an infected flock
could be removed from the distribution chain before they reach
consumers. The report notes that thoroughly cooking eggs to 150
degrees inactivates the virus, but a few human illnesses are
possible from undercooking contaminated eggs.
USDA research has shown that time and temperature recommendations
for egg product processing can kill avian flu viruses. The report
said dried egg white processing may not completely inactivate the
pathogen, but the seven-day processing period may allow officials
time to alert egg product processors before the drying is completed
and the product is released to consumers. The USDA said its APHIS
division is developing a separate illness risk assessment for egg
products that are contaminated with avian influenza.
Once finalized, the avian flu illness assessment for poultry and
eggs will give risk managers the decision-making tools they need to
gauge the effectiveness of interventions that could reduce or
prevent foodborne illnesses, the report said.
"This risk assessment can also be used to target risk
communication messages, identify and prioritize research needs, and
provide a framework for coordinating efforts with stakeholders," the
[Text from file received from
Logan County Department
of Public Health]