#18,021
Although the USDA and FDA continue to reassure the American public that the food chain (including milk) is safe from HPAI H5N1, there remain unanswered questions about how widespread the virus is in cattle, and how effective regular pasteurization is in killing the virus.
While the extent of the spread in cattle remains unknown, 3 days ago the New York Times carried an article (see Scientists Fault Federal Response to Bird Flu Outbreaks on Dairy Farms) where they cite (so far, unverified) reports of positive tests from asymptomatic cattle in North Carolina.
Testing by the USDA of cattle has remained both limited and voluntary, and has so far only been recommended for symptomatic dairy cows (see APHIS/USDA Updated FAQ On Detection of HPAI (H5N1) in Dairy Herds).
This `don't test, don't tell' policy apparently extends to pigs as well, despite ongoing concerns that HPAI could find a home in swine herds (see EID Journal: Divergent Pathogenesis and Transmission of Highly Pathogenic Avian Influenza A(H5N1) in Swine).
An excellent overview by Jon Cohen in Science yesterday (see U.S. government in hot seat for response to growing cow flu outbreak) describes the parsimonious release of information by the U.S. government, along with the limited evidence on the effectiveness of standard pasteurization in deactivating the virus.
Under what I assume to be an abundance of caution, the CDC recently revised their food safety advice (see below) regarding HPAI, which now includes guidance on safely cooking beef (which, according to the USDA, are unlikely to be infected).
- Whole cuts of beef, veal, lamb, and pork, including fresh ham: 145°F
- Ground meats, such as beef and pork: 160°F
- All poultry, including ground chicken and turkey: 165°F
It is also worth mentioning that despite the mantra that `properly prepared foods are safe to consume', there may be some small risks entailed in the preparation of raw meat. PAHO (the Pan-American Health Organization) mentions this on their Avian Influenza landing page:
Transmission
The most common way for the virus to enter a territory is through migratory wild birds. The main risk factor for transmission from birds to humans is direct or indirect contact with infected animals or with environments and surfaces contaminated by feces. Plucking, handling infected poultry carcasses, and preparing poultry for consumption, especially in domestic settings, may also be risk factors.
In Asia, more than a few human HPAI H5 infections have been linked to preparing and cooking poultry. Although it gets mentioned, far more attention needs to be paid to safe food handling practices in this time of HPAI.
While I fully understand the USDA's desire to reassure the public about the safety of the food supply - doing so while slow rolling the release of information is a risky strategy.
Particularly when dealing with a virus with a history of repeatedly doing the unexpected.
