Assessing the Risks
How serious are the risks of avian influenza (commonly known as "avian flu" or just "bird flu") and bovine spongiform encephalopathy (which we call "Mad Cow")? Given that all of us will eventually succumb to something, the odds of it being either of these diseases at the moment would appear to be miniscule. In fact, when the risks are weighed against the costs and complications of tracking, you have to wonder if an enormous government-managed database that depends on reporting from the field about every animal movement is really the best way to handle the problem.
Let’s look at the stats.
The Chicken Stakes
At the time of this writing, the World Health Organization (WHO) cites more than 200 cases of humans who have contracted avian influenza (H5N1), resulting in more than 100 deaths in nine countries. Since it was identified in 2003, the disease has spread through the movement of domestic and wild birds far from the initial cases found in Vietnam and Thailand to an ever-wider range that includes Denmark, Sweden, Germany, and Scotland. While some experts have predicted the arrival of avian flu on U.S. shores within a year, Dr. Wiemers takes a cautious approach, claiming "no crystal ball" and maintaining that the USDA is "hoping for the best, preparing for the worst."
As epidemic threats to humans go, the risk has so far remained small, limited primarily to those who work in the poultry industry. According to the WHO site, at the time of this writing there have been no confirmed cases of human-to-human transmission of avian flu (which would signal the risk of worldwide pandemic).
The danger to birds, however, is dramatic, including about 150 million so far that have died or been killed in an effort to stem this scourge, but controlling the spread is expected to take years. For chickens, this strain of avian flu is lethal within 48 hours, suggesting that the 48-hour trace-back target proposed by NAIS might not be fast enough for this particular pathogen. Certainly by the time an individual farmer learns that some of the birds just purchased might be infected, all of them could have the disease, and many a hen might be lying toes-up.
But Wiemers insists that the 48-hour trace-back should be sufficient for damage control. In that time, the USDA should completely understand the spread of the infection, which animals were exposed, which premises were contaminated, which chickens are at risk. In fact, he sees poultry producers as responding far more quickly: "Most of them can give us the information within 48 minutes."
In this regard, RFID might just offer an additional answer. In December 2005, Digital Angel, a manufacturer of RFID tags for animals, proposed using a biothermal chip for diagnosis. Usually, before it’s clear that an animal is ill, someone handling the poultry has to see a chicken sneeze, notice a discolored beak, or—more likely—observe that one of the broilers has dropped over dead in the chicken coop. Clearly what’s needed is an early-warning device. The biothermal chip can monitor and transmit information about body temperature. If a threshold number of birds register a fever, it’s time to check for an epidemic. Keven McGrath, President of Digital Angel, has suggested tagging one chicken in every 250 with a biothermal device.
So far, though, no one seems to be slapping RFID tags on their layers for ID purposes. "In fact, there’s very little RFID being used with poultry," says Wiemers, adding that chickens are generally tracked through "visual identification" methods that "don’t employ automatic data capture." Pilot projects for chickens rely on labels with the ID number attached by leg bands, metal clips, glue, or those plastic T-fasteners that attach price tags to clothing.
While some independent producers with modest holdings may need to identify birds individually, commercial poultry birds might only be marked with a lot ID number if they’re raised and shipped together, and don’t ever commingle with other birds.
Is this sort of thing enough to safeguard our food supply? Maybe.
First, our food is not currently at risk from bird flu. According to the WHO FAQ on avian influenza, risks to food supply exist only in countries with a confirmed outbreak. For the rest of us (for now, at least), eating chicken is as safe as it ever was. Better yet, even where bird flu outbreaks have been confirmed, cooking destroys the virus, so cooked poultry and eggs are safe. Just remember that wherever there have been confirmed cases of avian flu, even the yolks of eggs must be fully cooked; so if the epidemic reaches us next year, as expected, don’t order your eggs "over easy."
The New Brand on Cattle
The risks to humans from bovine spongiform encephalopathy (BSE) would appear to be very tiny indeed. According to the Centers for Disease Control (CDC), the U.S. sees fewer than 300 confirmed cases per year of Creutzfeldt-Jakob Disease (CJD), the neurodegenerative disorder related to BSE that humans can contract. Moreover, virtually none of these are the variant Creutzfeldt-Jakob Disease (vCJE) that comes from eating BSE-infected beef. In fact, according to WHO, no cases of vCJE to date can be traced to eating beef in the U.S., the single case occurring here being attributable to that individual’s having "lived in the UK during the BSE epidemic."
So far, the Food and Drug Administration (FDA) and USDA cite three confirmed cases of BSE in the United States (December 2003 and June 2005, March 2006). All animals were apparently born before the 1997 regulations that prohibited the recycling of cattle parts into cattle feed, a practice that has been tied to the spread of the disease. Meat from both the 2005 and 2006 cases was stopped at the slaughterhouse because regulations prohibit distribution of meat from a "downer" cow (one that’s unable to walk).
The 2003 BSE case, the first in the US, was more problematic. While the FDA insists that the organs that carry the infectious proteins (called prions) were discarded at slaughter, the meat from that cow did enter the food chain. Ground beef from that cow was mixed with meat from several others and subsequently sold in stores in the state of Washington. While 10,000 pounds of beef were recalled, the recall came too late for some who took it home to cook tacos and spaghetti. Unfortunately, cooking doesn’t make beef safe from this risk.
But, that said, risks should be negligible in cases where organ and nerve tissue have been discarded, as was done in the case cited above. Muscle tissue doesn’t carry the risk of infectivity, according to a WHO fact sheet on BSE—and, just for the record, neither does milk.
For those who are still concerned by the small percentage of cattle tested for BSE in the U.S., there’s always the option to limit consumption to organic beef, which has never carried the risk of recycled cattle feed.