The cattle got BSE from this feed, says Hueston, and then their remains were recycled as meat-and-bonemeal, which infected more cattle.
Could the same thing happen here? All it may take is one infected sheep or cow or one contaminated batch of animal feed.
The government has set up several firewalls to keep mad cow disease out. One protects cattle from BSE; another prevents people from getting sick if the first one fails. So far, both seem to be working, but both have gaps in them.
In 1997, the FDA prohibited animal-feed mills from mixing meat-and-bonemeal made from rendered cows and sheep into feed for cows or sheep. (The supplements can be fed to pigs and poultry, because they dont get BSE-like diseases from food.)
But that ban isnt foolproof. In 1998 and 1999, the FDA inspected 63 plants that render both ruminants (cattle and sheep) and non-ruminants (pigs and poultry). Ten of them had no system in place to keep the two apart. Thirty-seven of the 300 feed mills that handle both ruminant and non-ruminant meat-and-bonemeal also had no system to keep them apart.
The problem made headlines last January, when a Texas feedlot inadvertently fed meat-and-bonemeal intended for pigs and poultry to more than 1,200 cattle. A clerk at Purina Mills in St. Louis had mistakenly mixed the supplement into the companys cattle feed. Although the meal was produced from BSE-free cattle, Purina Mills purchased the animals and turned them into pig and poultry feed.
The FDAs inspection results were a real eye-opener for the rendering and feed industries, which are scrambling to police themselves before the Feds step in. Or before Ronald McDonald does.
The restaurant chain that buys more beef than any other has been stung by sharply lower sales at its European outlets. It doesnt want to see the same happen here. So McDonalds has told its U.S. suppliers to document that their cattle havent been fed meat-and-bonemeal made from cows or sheep.
The U.S. has always been BSE-free, says McDonalds spokesman Walt Riker. McDonalds has the worlds biggest shopping cart, and we try to use that leverage for good.
When McDonalds talks, the beef industry listens.
Were calling for the complete removal of ruminant-derived meat-and-bonemeal from those plants that make feed for cattle, says Richard Sellers of the American Feed Industry Association, which represents nearly 700 feed companies. That should prevent the accidental mixing of the two kinds of feed.
Weve already set up an independent third-party certification program to verify that our members are following all FDA regulations about the proper labeling of their products, adds Sellers.
The rendering industry is doing likewise. On April 1, we began to have outside inspectors verify that renderers are following all government regulations, says Tom Cook of the National Renderers Association.
Another potential breach in the BSE firewall has already been plugged. Up until 1998, many slaughterhouses stunned their cattle with an air-injection rifle before killing them. The explosive blast of air to the head often scattered brain tissue throughout the carcass (see July/August 1997, cover story). In cows with BSE, brain tissue is highly infectious.
The beef industry has eliminated air-injection stunning because of the potential for contamination, says Janet Riley of the American Meat Institute, an industry group. No one is even manufacturing the equipment any more.
Prions mostly infect an animals brain and spinal cord, not its meat. So how did 101 people (so far) in Europe become infected with vCJD? Most likely from eating inexpensive beef products that contained mechanically separated meat, says the NIHs Paul Brown.
Mechanically separated meat is a paste produced by compressing carcasses, much like a used car is crushed into a dense block of metal, he explains. The British meat industry used this extruded paste, which could have included spinal cords, in hot dogs, sausages, and burgers.
So, while a filet mignon was safe to eat, says Brown, a hot dog made with mechanically separated meat was not at all safe.
This year, the European Union banned mechanically separated meat made from cattle and sheep, though as of April the ban hadnt fully taken effect.
Unfortunately, the U.S. hasnt done the same. Mechanically separated beefspinal cords and allis still allowed here, though its hard to get a handle on how common it is.
In the U.S., mechanically separated beef is rarely used any more, says Janet Riley of the American Meat Institute. The machinery was expensive and there were too many restrictions on how the product could be used, adds the USDAs Bob Brewer. Yet neither the AMI nor the USDA can say how muchif anymechanically separated beef Americans eat each year.
The good news: Any food that contains mechanically separated beef has to say so on the label. The bad news: There are no labels when you eat out. So its possible that hot dogs, sausages, hamburgers, and some other restaurant foods made with ground meat could contain spinal cord tissue. If mad cow disease ever shows up in the U.S., that could spell trouble.
Many U.S. meat processors have switched from mechanically separated beef to advanced meat recovery (AMR),
which also extrudes meat from carcasses under pressure, but without crushing the bones. That alone makes it less risky than mechanically separated beef. More than 60 percent of cattle are now processed using AMR, which has a huge competitive advantage over mechanically separated meat. Its not a paste, and labels dont have to identify it. AMR meat often ends up in hamburgers, hot dogs, sausages, and the meat in pizza toppings and taco fillings.
Companies are supposed to remove the animals brains and spinal cords before putting the carcasses through the AMR machinery, but getting out all of the spinal cord isnt easy. It requires special tools and skills, says Glenn Schmidt, a meat scientist at Colorado State University. The workers have to reach down to the neck region of the carcass to remove the spinal cord by scraping or suction, and sometimes they dont get all of it.
Sometimes is right. Since 1996, USDA surveys have turned up spinal cord tissue in four of 70 samples of AMR meat. That worries the U.S. beef industry, which has seen its European counterpart
decimated by the mad cow scare. The National Cattlemens Beef Association has hired Schmidt to test the meat produced at the eight major AMR plants.
Were finding that some companies are succeeding at keeping spinal cord tissue out, while other companies are still working toward that goal, says Schmidt.
The only way to guarantee that AMR meat is free of nervous-system tissue is to require meat processors to remove the entire spinal column (bones and all), not just the spinal cord, before sending cattle carcasses through their machinery (see Making Meat Safe,).
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Whats the risk of getting variant Creutzfeldt-Jakob Disease from eating meat?
Beef is safe to eat in countries where the cattle dont have BSE. In countries where BSE has been found, its safe to eat boneless steaks, roasts, and other muscle meats (see When You Travel,). But youd be smart to avoid processed meats like burgers, sausages, and the meat toppings on pizzas. (McDonalds, Burger King, and Wendys, the three chains we contacted, say that they have never used advanced meat recovery or mechanically separated meat in any of their outlets in the U.S. or abroad.)
Pork and poultry are safe, even in countries where cattle have BSE. We can produce a BSE-like disease in pigs in the lab by injecting infected tissue into their brains, says the National Institutes of Healths Paul Brown, but not by putting it into their food. Poultry dont seem to get BSE-like diseases.
Fish and shellfish caught in the wild are safe, even in countries where cattle have BSE. Farm-raised fish should also be okay, since theyre mostly fed fish meal and soybean meal, neither of which carries infectious prions.
Lamb and mutton are safe, even in countries where cattle have BSE. Theres never been any evidence that humans can get a brain disease from eating the meat from sheep or goats with scrapie, says Paul Brown.
Dairy products are safe, even if they come from cows with BSE. Milk and other dairy products
dont carry infectious prions.
Game meat like wild elk and deer can suffer from chronic wasting disease, which occurs naturally and belongs to the same family of prion diseases as scrapie, BSE, CJD, and vCJD. No cases of humans getting a brain disease from eating wild game with chronic wasting disease have ever been documented, says the NIHs Paul Brown. Still, he adds, youd have to be crazy to eat the brain of a wild animal.
Gelatin is an animal protein that comes from the hides and bones of cows and pigs. Its what makes Jell-O gel and gummy bears soft and pliable. Its used as a thickener in some yogurts, ice creams, and other foods. And its in the capsules, gel caps, and coatings of many over-the-counter supplements and prescription drugs.
Is gelatin infectious if its made from animals that have mad cow disease? Probably not. Skin and hides dont seem to carry any risk, while bones have a low infectivity (because they contain bone marrow), according to the World Health Organization.
In 1997 the FDA prohibited gelatin manufacturers from using hides and bones from cows with any signs of neurological disease.
Many confectioners do not use beef gelatin, says Susan Smith of the National Confectioners Association. But some do. (You cant tell from the label.) We use mostly pork gelatin to make our Jell-O, says Claire Regan of Kraft Foods.
Few if any scientists see a problem. Gelatin is off my radar screen, concludes BSE expert Will Hueston of the Virginia-Maryland Regional College of Veterinary Medicine.
Vaccines are often made using cattle by-products that could be infectious. But there is no evidence that any of the worlds 101 cases of variant Creutzfeldt-Jakob Disease were caused by contaminated vaccines. Nevertheless, in 1993 the FDA asked vaccine manufacturers to stop importing animal products from countries where BSE is known to exist or may exist. Last year the government learned that five vaccine-makers hadnt complied and ordered them to do so. Clearly, the benefits of vaccination outweigh a risk that the government considers theoretical and remote.
Glandular supplements are often made from animal parts that could be infectious. Natures Plus Ultra Male, for example, contains cow tissue from the brain, eyes, pituitary, and spleen.
The major supplement-makers say that theyre complying with a 1993 FDA request that they not use cow tissue from countries where BSE exists or may exist.
Weve found that almost all of our suppliers use only domestic cattle as sources, and that those that do import bovine-derived materials do so from non-European countries, says Phillip Harvey of the industrys National Nutritional Foods Association. Thats based on a NNFA survey of its members.
But the FDA has no system in place to monitor what companies actually put into their supplements. Our advice: avoid any supplements that contain animal brains, eyes, or glands, especially since theres little evidence that they work.
Click here for links to the most useful Web sites with information on mad cow disease.