A single case of Mad Cow disease on a dairy farm in the United States last month has sent shock waves through the nation's $175 billion beef industry. But as journalist and veterinarian Mark Jermone Walters claims in his book Mad Cow is just part of a wave of new global infections. Since the Washington state mad cow incident was first reported last month, 36 countries have banned the import of U.S. beef and a study by the National Cattlemen's Beef Association reports a 15 percent drop in cattle prices, a significant shock to the U.S. farm economy.
A CNN-Time poll released last week says 27 percent of Americans have either reduced their consumption of beef or stopped eating it altogether. Since the mad-cow epidemic emerged in Europe in the early 1990s much has been learned about the brain-wasting disease. At its peak in England approximately one million cows were slaughtered. New international rules, including a ban on feed rendered from potentially tainted animal parts have worked to curb the infection. Author Mark Jerome Walters says old diseases like malaria and tuberculosis, once thought to be controlled, are re-surging. Others like Mad Cow, Lyme disease, Salmonella, SARS, Hantavirus and HIV-AIDS the six epidemics discussed in his new book - are imposing new public health risks.
"And so you find this whole range of new infections, from old to new that is reconfiguring itself. It is mutating," said Mr. Walters. "There is some reason that this is all happening together. And the reason is that we have made radical changes in the environment and thereby put humans in the way of diseases that evolutionarily did not tend to mess [bother] us very much."
Mr. Walters says in his introduction to the book that the larger story is not simply that humans and other animals are falling victims to new diseases, but that humans and animals are causing these diseases or making them worse.
"One of the points that I wanted to make in my book was to begin to get past the old human archetype of [that] 'we are in a war against Nature and if we don't watch out, Nature is going to victimize us,'" he added. "How often we hear about human beings being victimized by disease as if we had absolutely nothing to do with it. We have made changes to the environment, to the ecology, to the natural systems that support us, that has caused the emergence and spread of these new diseases."
"It falls into several categories and sometimes several overlap: for example, agriculture," replied Mr. Walters when asked: How do you connect the emerging health risks to human-imposed environmental changes? "We have seen that industrialized agriculture is clearly responsible for the spread of mad cow disease," he said. "Cattle were never meant to eat meat, let alone each other. You find with industrialized production that the traditionally discarded parts of cattle were ground up and rendered into pellets and fed back to cattle. They were being fed their pasture mates.
"This was a disruption of the natural food chain," continued Mr. Walters. "Consequently mad cow spread very rapidly. That's just one example. We even see [this] in West Nile Virus. Currently Colorado is being hit very badly by this virus which is new to the Western hemisphere as of 1999 [and] there have been over 40 deaths there. One of the reasons it has hit so hard there is that the mosquito that transmits it in that part of the west breeds very well in irrigated fields. And, because of the farming there it has created an ideal habitat for these mosquitoes. So, time and time again with antibiotic resistant disease, salmonella food poisoning, which is common in the U.S. and elsewhere. We feed antibiotics to cattle, not because they are sick, we feed antibiotics to cattle to make them grow faster or to prevent disease because they are kept in naturally unsanitary crowded conditions. And so here we see essentially a public health tool being used to make money at the expense of public health." Twenty three thousand cases of Lyme disease were reported in the United States in 2002. Infected deer ticks are the culprits. Mark Jerome Walters says rapid forest fragmentation has led to an increase in mice and deer, two species that help spread the disease. But, he says, other environmental factors come into play. "The spread of this tick seems to be correlated with temperature rise in the mid-Atlantic [states] and higher humidity and that has permitted the tick apparently to spread further," said Mark Jerome Walters. Now you add to that to have people move from cities to have their 'little kingdoms' homes] at the edge of the woods and you have a perfect confluence of events that have resulted in a very big, serious public health problem."