Many people know that diets filled with animal-based foods can lead to chronic illness, but few realize that livestock diseases can also affect human health. Factory-farmed animals are afflicted by many diseases, and increasing consumption of cattle, pig and chicken carcass is leading to more frequent outbreaks of plague, swine and bird flu among animals. Moreover, rearing more animals increases the possibility of disease mutation and pandemic among humans.
A panzootic is an outbreak of an infectious disease of animals that spreads across a large region, for example a continent, or even worldwide. The equivalent in human populations is called a pandemic. High population density is a major contributing factor to panzootics and vast amounts of antibiotics are used to keep diseases at bay in concentrated animal feed operations, with varying success. So far, livestock diseases have had a relatively minor impact on human health, which is an amazingly lucky break, but luck like this does not last long.
Cattle plague is a panzootic that recurred throughout history, often accompanying wars and military campaigns. Cattle plague affected Europe especially in the 18th century, with three long panzootics from 1709-1720, 1742-1760, and 1768-1786, that affected millions of livestock. There was a major outbreak covering the whole of England in 1865/66. Later in history, an outbreak in the 1890s killed 80% to 90% of all cattle in southern Africa, as well as in the Horn of Africa. More recently, a rinderpest outbreak raged across much of Africa in 1982-1984, costing US$500 million in losses.
In 1996, the UK culled 4.4 million cattle to eradicate mad-cow disease, while 400,000 were killed in 2001 in Germany. In 2009, Egypt ordered the cull of all pig herds, over 400,000 pigs, to avoid swine flu. In 2014 in the US, seven million piglets, or 10% of piglets born, died due to Porcine epidemic diarrhea virus. A 2015 outbreak of avian flu in the US led to the culling of 50 million birds, or more than 10 percent of US chickens raised to produce eggs. The H5N2 virus affected 39 million chickens, at least 33 million of which were laying hens, and 7 million turkeys.
Avian flu is a serious disease than can easily become a panzootic and imperfect disease-surveillance systems mean that occurrence of the virus remains underestimated and underreported. And, if the avian influenza virus combines with a human influenza virus in a bird or a human, the new subtype could be both highly contagious and lethal to humans.
Alarmingly in 2003, SARS became the first serious, easily transmitted disease to emerge in the twenty-first century, in Hong Kong. And in 2009, an unusually mild H1N1 influenza virus infected as many as a hundred million Americans and nearly a billion people throughout the world. If H1N1 had been more virulent, it would have killed millions of people. MERS, or Middle Eastern Respiratory Syndrome, is similar in many ways to SARS, and appears to have jumped from camels to humans. It can be deadly, though, and there is no cure.
Despite the massive infection of birds and pigs in the US, most Americans are complacent since no human lives were lost. But even when a panzootic mutates and starts to affect humans, the danger is still not realized and acted upon. Over 131 H5N1 outbreaks were reported worldwide from 2006-2008 in five countries - China, Egypt, Indonesia, Pakistan and Vietnam. And since 2003, there were 630 confirmed human cases, which resulted in the deaths of 375 people.
In 2014 alone, there were dozens of panzootics across the world. Concerns over avian influenza in South Korea led to 14 million birds being culled in 2014, and 324,000 in China, another 46,000 in North Korea, 112,000 in Japan, 64,000 in Vietnam, 40,000 in Holland, 38,000 in Germany, 20,000 in Hong Kong, and thousands more in Nepal. In northeast China, after 18,000 geese died from H5N6 bird flu, and 69,000 were culled.
Beijing in 2014, 20,000 ducks died suddenly due to avian influenza,
while 10,000 chickens died in Malaysia. And in Sweden, 24,000
chickens were culled due to outbreak of paramyxovirus type 1 disease.
Also, in 2014, thousands of chickens died in Indonesia from Boyolali
Importantly, "superbugs" are showing up in hamburger meat, and a recent study found bacteria on all of the beef samples they tested. Nearly 20% of the beef samples contained illness-causing C. perfringens, and 10% contained a strain of toxin-producing S. aureus bacteria that cannot be destroyed with proper cooking.
Demand for animal products is projected to increase by 50% from 2013 to 2025. This will dramatically increase incidences of disease and risk to human and animal health. Adopting a plant-based diet could significantly reduce the risks of panzootics and pandemics, and lower greenhouse gases significantly.
For excerpt from the book, "Meat Climate Change," see http://meatclimatechange.org/