Arno Karlen died a year ago this past May. Too bad. I’d like to ask him about beef’s food safety efforts. I wonder if he would think that we will ever get food clean enough to prevent food poisoning.
I don’t think we will. I don’t think it’s possible.
I think Karlen’s 1995 book Man and Microbes: Disease and Plagues in History and Modern Times should be required reading in American high schools. It recognizes that humans and disease-causing organisms have evolved (and continue to evolve) together. As our forebears changed their habits—developed agriculture, moved to crowded cities and opened new lands and trade routes—they continually ran into new disease pathogens.
It was always nasty. Lots of short lives and dead babies. Until science came along.
The book cites an estimate by researchers that interaction with dogs, cattle, sheep, goats, pigs, horses and poultry introduced more than 250 new zoonotic pathogens. "Agriculture brought
humans so many new pathogens that it seems wondrous they survived," Karlen wrote.
Many—sometimes millions—died with each new exposure and each new plague, but everything that didn’t kill the survivors made them stronger. They developed immunities to these pathogens. The epidemics that decimated the New World populations when Europeans arrived were just a fast-forward version of the history of the Old World.
Until the advent of modern science, we were forced to submit to nature’s rules through a cruel system of survival of the fittest. Mother Nature is a bad mother when she wants to be.
So thank science and technology for a more humane system. We’ve learned that certain hygiene practices—things like sewers, rat traps and washing our filthy hands—help. We’ve got antibiotics and vaccines that simulate exposure and resistance without all the suffering that nature requires.
Exceptions to the rule. Karlen pointed out that most of the diseases that afflicted us historically were rooted in filth. Polio was different.
Nobody knows when it started, but polio wasn’t much of a problem until people learned to clean up. Even during the height of the epidemic in the 20th century, polio was virtually unknown in less developed countries. That confused researchers until they found that the virus was common in human populations. It’s just that most people were immune, because their lifestyles had challenged their immune systems early.
"The virus, once ubiquitous and silent, became a problem in advanced nations when poverty and dirt dwindled," Karlen wrote. "Researchers found that in warm, crowded cities such as Cairo and Bombay, most children were exposed to the polio virus and immune to further attack by age 3; paralysis and death were rare. This must have been true in the crowded, unhygienic cities of the West until the late 19th century."
Which brings us to the late 20th and early 21st centuries and asthma. It is an increasing problem in the U.S., but—like polio a century ago—not in the developing world. According to one school of thought, the explanation might be that kids today live in such a clean world that their immune systems don’t develop right.
Now, what I know about the immune system I learned mostly by asking veterinarians about dead calves. But I know that, in general, younger calves react better to vaccines than older ones. It’s like what they say about chicken pox: If you get it early, it’s no problem. If you catch it as an adult, then you’re in trouble. Your immune system is like your brain: It learns better early than it will later.
The theory about asthma is that the immune system hasn’t learned how to handle a bad bug, so it goes all haywire. Asthma—and things like salmonella and E. coli—are more common among town kids than rural kids. You know why. Rural kids play in dirt at the time of life nature designed humans to play in dirt. They get a little bit of this bug and a little bit of that bug, and their systems get battle-hardened.
Here is how all this applies to beef safety. The beef checkoff folks and the meat processing industry have been investing a lot of effort and money to keep beef free of manure, resulting in a vastly improved food safety record in recent years.
Still, there are occasional outbreaks of E. coli. This spring’s headlines about non-O157 E. coli problems in Germany did nobody any good. No matter how hard the industry works, there will be mistakes. With the epidemiological reporting capabilities of the modern health care system, and the Chicken Little media megaphone, each incident will be a threat to more than the folks affected. It will impact beef demand.
Staying clean is crucial, and USDA’s new test-and-hold rules are fine. But the industry’s best hope for E. coli is not just cleaner beef and more inspection, but a useful vaccination. For cattle and for humans.
Vaccines to the rescue. And there is good news on that front. Two companies have promising vaccinations for cattle on the market. They both bode to drastically reduce the incidence of O157 and one has already said its product holds promise on the other serotypes.
The $10 per head cost looks nearly reasonable to me. That would be $1,000 on a pen of 100 head, which strikes me as high. But, thinking like one of those oversanitized town mamas, and assuming I eat a typical tenth of a steer a year, that would give me 99.5% (Bioniche Life Sciences says that’s how much its vaccine would reduce shedding) insurance against E. coli for about $1. My guess is most mamas would pay that happily.
But the one I’m really hoping for is the human vaccine Novartis is working on. The reason I eat rare hamburger when I can is that I figure all the cow manure I’ve eaten on sandwiches and breathed in pen dust has probably inoculated me pretty well against not only asthma, but anything a cow is likely to offer. If we could get all kids to eat some cow pie, my theory is, we could forget food safety in the packing plants and concentrate on juiciness and tenderness.
I exaggerate, of course. We need to keep the manure out of the beef. But vaccines might prevent mistakes from becoming tragedies. As Karlen would tell you, we’ll never win our battle with microbes. They will continue to adapt and so will we. But with the help of our modern technology—from hygiene to vaccines—it makes it so much easier than having Mother Nature take her amoral course. There are so many fewer dead babies this way. And that’s a good thing.
- September 2011