Animal Origins of Deadly Disease Outbreaks

Mar 09, 2020

"[H]umans do have a knack of choosing precisely those things that are worst for them."
-J.K. Rowling,
Harry Potter and the Sorcerer's Stone

Coronavirus

The current disease rampaging through the world and casting fear into the hearts of all is the coronavirus, which is, surprisingly, not caused by cheap beer. Unfortunately, the true origins of this virus are far more sinister. This particular coronavirus is called COVID-19, meaning that it is a new coronavirus, it originated in animals and spread to humans, and it began in 2019.[1] It all started in a "wet market" in Wuhan, China; at these markets, live wild animals are kept confined in tanks, cages, and tubs so customers can pick individuals to have slaughtered before them. There have been outbreaks similar to this in the past, in particular the 2003 SARS epidemic that also originated in a Chinese wet market. Genetically, this virus is nearly identical to SARS, and scientists have determined that COVID-19 originated in bats and was then transmitted to another wild species.[2, 3]

After initial human contamination, the virus spreads through "respiratory droplets" from person-to-person. This means that simply breathing on something or someone can cause the virus to spread.[4] While the specific chain of events that caused this most recent coronavirus outbreak may still be unknown, it's clear that the cramped, squalid, bloody conditions of these wildlife wet markets are a breeding ground for disease.

H1N1

The swine flu made its rounds across the globe in 2009, originating in Mexico and quickly spreading into the rest of the Americas and internationally. The origins of H1N1 date back 90 years prior, however, with the Spanish flu pandemic of 1918. Before appearing in humans in early 2009, this particular strain of the virus had been growing in a Mexican pig population for a decade before becoming strong enough to infect humans.[5] By October 2009, the spread had slowed down, and the virus became treatable. Afterward and to this day, it spreads seasonally just like the common flu.[6]

Mad Cow Disease

Bovine spongiform encephalopathy (BSE), or mad cow disease, "is a progressive neurologic disease of cows. Progressive means that it gets worse over time. Neurologic means that it damages a cow’s central nervous system." It is caused when a normal prion protein becomes abnormal, thereby resulting in common neurological symptoms, like imbalance and incoordination, and causes the brain to appear sponge-like.[7]

BSE is thought to be transmitted to humans through the consumption of the flesh of cows with the disease. Additionally, cow body parts that are not suitable for human consumption are then fed back to other cows, spreading the disease to these unfortunate accidentally-cannibalistic cows. Because the incubation period for the disease is about four to six years (in cows), and cows are generally slaughtered younger than that, it's easily conceivable that many cows could be killed without farmers being aware that they were infected at all. While BSE has been all but eliminated in cattle in recent years, with a human mortality rate of 100%, that's still a terrifying prospect.[7, 8]

Ebola

The Ebola virus originates from three species of fruitbats found in Africa living around the Ebola River. "The virus spreads to people initially through direct contact with the blood, body fluids and tissues of animals. Ebola virus then spreads to other people through direct contact with body fluids of a person who is sick with or has died from EVD."[9] Since it’s animal-borne, in what context would a human come into contact with the fluids and tissue of a nonhuman? Well, by eating them. Apparently, "bat soup is a delicacy in the region," meaning that people capture and eat the flesh and fluids of the bats.[10] Then, the humans contaminated can easily pass the virus on to others if they haven't properly sanitized themselves or any other surfaces that came into contact with the slaughtered animals.

Bird Flu

Avian influenza viruses are transmitted through direct or close contact with birds and bird products carrying the disease. According to the CDC, "infections with bird flu viruses can happen when enough virus gets into a person’s eyes, nose or mouth, or is inhaled. This can happen when [the] virus is in the air (in droplets or possibly dust) and a person breathes it in, or when a person touches something that has [the] virus on it then touches their mouth, eyes or nose."[11] It can also be transmitted through intermediate hosts, which are other species that have also been infected (a common example of this is H1N1).[12] Known strains of bird flu can be treated with antiviral medication, and are rarely contagious from person-to-person.[11]

Salmonella

"Salmonella bacteria typically live in animal and human intestines and are shed through feces." Most people are infected by consuming raw or undercooked meat (including seafood), poultry, or eggs; this generally only happens when these products have been contaminated with feces. However, many people with salmonella may not even realize it, as experiencing symptoms is rare.[13] This doesn't come as a surprise because almost all meat is contaminated with feces: "90 percent of chicken parts, 91 percent of ground turkey, 88 percent of ground beef, and 80 percent of pork chops are tainted on the retail level nationally."[14]

In 2014, a Consumer Reports study found that 97 percent of chicken breasts are contaminated with harmful bacteria, and 38 "percent of the Salmonella they found was resistant to multiple antibiotics." In eggs, Salmonella thrives and can even survive being boiled for more than eight minutes. Approximately 142,000 Americans get Salmonella poisoning just from eggs every year.[14]

E. coli

E. coli is an intestinal pathogen found only in animals. Most E. coli outbreaks originate from raw meat and milk, undercooked meat, and vegetables contaminated with animal feces.[15, 14] Like Salmonella, E. coli is generally the result of fecal contamination. In fact, applying "manure to crops has been found to increase the odds of E. coli contamination by more than fiftyfold."[14] While very few people have died from contracting E. coli, this shows that animal agriculture just adds unnecessary risk to human health.

African Swine Fever

I heard about ASF on the news recently and was interested in researching it for this post. However, it is (supposedly) not contagious to humans, so why am I discussing it here? Well, let me share an excerpt from a USDA article about it:

"African swine fever is a highly contagious and deadly viral disease affecting both domestic and wild pigs of all ages. ASF is not a threat to human health and cannot be transmitted from pigs to humans. It is not a food safety issue."[16]

"It is not a food safety issue." Doesn't that sound strange? How could it possibly not be a food safety issue? If a pig contracted this extremely deadly and contagious virus and was then sent to slaughter, that wouldn't be a problem? Obviously, I'm no expert on diseases, particularly those relating to nonhumans, but there's no way I would want to eat something contaminated with any kind of disease. And it makes me wonder what other bacteria, viruses, etc. can be present in an animal and their flesh or secretions and then sold for human consumption. This is especially concerning after learning about how swine flu was alive and well in pig populations for years before it became a threat to humans. Could ASF be the next global pandemic?

Vegan for Health

If people simply ate a natural diet of wholesome plant foods, the odds of these disease outbreaks occurring would be infinitesimal. Even "vegan" products like spinach and romaine lettuce would fail to be potentially hazardous because they would no longer be exposed to animal-based fertilizers. Honestly, it's like we're trying to kill everyone and everything in every possible way. But, on some level, we realize that animal consumption is the cause; we all know by now that these diseases are animal-borne.

I believe the reasons why we feel so little need to act are because, in the Western world, we are at much lower risk of exposure to most of these illnesses; it's not our problem because it's happening to people far away, and we have our own issues. (And even when it does reach us, we still don't feel directly threatened by it; "there's no way that could happen to me.") Then, we assume that these less-developed countries simply don't handle livestock appropriately to prevent contamination, which may be true on some level, but is an apathetic response, as many people in these countries are impoverished and have few other options. We all share responsibility for these problems, and as long as animals are exploited in the food industry, our health will continue to be at risk every time we eat.