FSIS Seeks Comments On Draft Risk Assessment For The Public Health Impact Of Highly Pathogenic Avian Influenza Virus In Poultry, Shell Eggs, And Egg Products

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WASHINGTON, Dec. 2, 2008 - The U.S. Department of Agriculture's (USDA) Food Safety and Inspection Service (FSIS) is seeking public comments on a draft quantitative food safety risk assessment for highly pathogenic avian influenza (HPAI) virus from consumption of poultry products, shell eggs and egg products. The risk assessment was done in collaboration with the Department of Health and Human Services' Food and Drug Administration (FDA), and USDA's Animal and Plant Health Inspection Service (APHIS).

The risk assessment was designed to evaluate the relative effectiveness of strategies to reduce or prevent exposure to HPAI virus from consumption of poultry meat, shell eggs and egg products.

The risk assessment is available on FSIS' Web site at http://www.fsis.usda.gov/Science/Ris...ents/index.asp. For further details on the risk assessment, please contact Neal J. Golden, Office of Public Health Science, FSIS, by phone at (202) 690-6419 or by e-mail at Neal.Golden@fsis.usda.gov.

Comments on the risk assessment must be received by Jan. 31, 2009.

http://www.fsis.usda.gov/News_&_Events/NR_120208_01/index.asp

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Re: FSIS Seeks Comments On Draft Risk Assessment For The Public Health Impact Of Highly Pathogenic Avian Influenza Virus In Poultry, Shell Eggs, And Egg Products

From the .pdf download:

1. Poultry Model
? If a flock is exposed to HPAIV, the model predicts a 94 and 98% probability that a chicken and turkey flock, respectively, would be identified as HPAIV-positive beforeslaughter and not enter commerce. This is because flocks infected early in the grow-out period will have enough time to demonstrate significant mortality (≥ 2% flock morality over a single day) on the farm, resulting in identification of the flock as HPAIV-positive.

? There is a 6 and 2% probability that an HPAIV-infected chicken or turkey flock, respectively, may go to slaughter without detection of the disease. This would happen when HPAIV infects a flock that is approaching market weight with not enough time for the flock to demonstrate significant mortality on the farm. In these instances, some fraction of HPAIV-contaminated poultry meat may enter commerce.

? On-farm HPAIV testing as a potential mitigation strategy has the greatest impact of lowering predicted illnesses. Approximately 95% of illnesses are mitigated if flocks are tested immediately before being sent for slaughter.

? Increased on-farm surveillance of daily flock mortality is predicted to reduce human exposure and illness. However, the model predicts that relying on a single day of flock mortality to detect all HPAIV-infected, but undetected flocks is impractical. This is because a flock may have few dead birds if infected late in its grow-out period as about 36 to 42 hours are required before infected birds die from HPAI.

? Increased surveillance at processing during FSIS? antemortem inspection is predicted to reduce human exposure and illness. However, the model predicts that using the number of dead birds following transportation to trigger detection of all HPAIV-positive flocks is impractical given that a flock may have few dead birds if infected late in its grow-out period.

? Cooking poultry to the FSIS recommendation of 165?F is predicted to inactivate the virus and result in negligible risk to public health from HPAIV-contaminated poultry meat.

? Cross-contamination of HPAIV from contaminated poultry to foods not likely to be cooked resulting in oral uptake increased the number of predicted illnesses by approximately 2.5%. Consumer messages should continue to emphasize measures to prevent the potential cross-contamination of HPAIV and other microbiological hazards.

2. Shell Egg and Egg Products Model
? If a 100,000 hen flock becomes infected with HPAIV, the baseline scenario predicts that 11,293 HPAIV-contaminated eggs are produced before the flock is discovered as HPAIV-positive. However, the baseline model predicts no human illnesses because > 99.99% of HPAIV-positive eggs would still be in the distribution chain at the time of diagnosis and not yet be available for consumers to purchase. This assumes that all HPAIV-positive eggs can be removed from distribution.

? If the risk assessment model baseline assumptions are changed using scenario analysis, HPAIV-positive shell eggs may enter commerce. Thorough cooking of eggs (150 oF) results in inactivation of the virus; however, if eggs are not cooked completely, the model predicts a few illnesses are possible. For example, the model predicts two illnesses may occur before a flock is identified as HPAIV-positive in a scenario where eggs reach market within 24-hours.

? As a mitigation strategy, removing HPAIV-positive shell eggs from commerce will reduce potential exposure. Effectiveness is dependent on how many days of eggs production are removed. The model predicts that greater than 97% of potentially contaminated shell eggs can be removed from commerce given a 2 day market withdrawal.

? In-shell pasteurization of HPAIV-positive eggs is predicted to inactivate the virus and result in negligible risk to public health.

? Data from USDA?s Agricultural Research Service show that FSIS time and temperature recommendations for egg product processing are sufficient to inactivate HPAIV, therefore this risk assessment model does not quantitatively assess the risk of illness from HPAIV-contaminated egg products. Only dried egg white processing may not completely inactive HPAIV; however, the process of preparing dried egg whites requires a minimum of 7 days. It is likely that the hen flock that produced the contaminated eggs would have been identified as HPAIV-positive before the process is completed, and egg products processors would be alerted to the problem. APHIS is currently developing a separate risk assessment to assess the risk of illness from HPAIV-contaminated egg products.