Many pandemic viruses and bacteria have reservoirs in the animal kingdom. Bats for example are carriers for many coronaviruses. Demand for meat brings these animals into direct contact with humans, enabling their jump from animals to humans. (Contact with animals required by the food industry is orders of magnitude more than other forms of contact - for example, contact required for scientific research.) Is it scientific to state that, therefore, if the demand for meat were to not exist pandemics would not occur? Or that their frequency would be vastly diminished?
If the wet, live animal market in Wuhan did not exist, would we have still had this coronavirus pandemic?
This thread is not to discuss vegetarianism vs meat-eating, but to understand what role food habits play in the emergence of pandemics driven by novel zoonotic pathogens.
No. And as a matter of fact, if we did not use cows for milk–as opposed to meat (and yes, I am aware of the veal/dairy connection), the discovery of the fact that immunity to vaccina (cowpox) conferred immunity to* variola* (smallpox) would not have been discovered.
All bacterial as opposed to viral, though, right? For whatever that’s worth. And yes, it’s thought that HIV jumped from two simian species through butchering.
True. Still, bovine TB was a major killer until Pasteur found out how to sterilize the milk (and quite a bit longer, actually; it took some time for his discovery to catch on!)
Marburg virus jumped to humans from lab monkeys. Hendra virus from horses. Nipah virus from fruits contaminated by bats. West Nile and Zika viruses from mosquito bites. There are many others. These aren’t pandemics, but they demonstrate that viruses can jump from animals to humans without any butchering of animals for meat.
As scr4 acknowledges, neither of these have, however, caused something even close to a pandemic! Which, of course, doesn’t mean they aren’t nasty and shouldn’t be avoided! (Don’t get bitten by wild animals, don’t eat jungle meat, and wash your fruit before consuming it!)
Hanta and plague still have local outbreaks, but can be quelled because we understand how to treat them. The novelty of COVID-19 is a big part of the problem.
ETA: Re: hanta: …and don’t clean up after mice without a good mask!
Measles, yellow fever, and polio are viral though. All are unrelated to the handling of animals for meat. Measles and polio are human diseases. Yellow fever has animal reservoirs that can be infected but mosquitoes are the main vector for transmission not handling. We have vaccines now but all have been pandemic at times in history. Due to low levels of vaccination for yellow fever it is considered possible that we might yet see another pandemic.
OK, so we have viral diseases, bacterial diseases, (human) pandemics and epidemics transmitted through (non-human) animals. I’m confounded. Anyone care to draw an Euler diagram?
Another thing that should be kept in mind when blaming omnivores for the spread of these sorts of viruses, is that in many cases the transition from animals to humans is through bush meat, where the animals have contact with pathogens outside the range of previous human habitation. So its not clear that middle class Americans switching to veggie dogs is going to close that vector. For the people who eat bush meat, it isn’t so much a culinary choice as an issue of survival, veggie dogs being few and far between in remote villages.
Everything I have read - on this forum and elsewhere - seem to point to the fact that while all contact with animals cannot be avoided (including exotic ones), handling of animals for food demand is a primary reason for the transmission of zoonotic viruses from their animal hosts onto human hosts. It does not help that some people in countries like China also like to feast upon living or minimally processed animals, or rare and exotic animals.
I believe the H5N1 avian influenza virus was also transmitted to humans due to contact with waterfowl, the natural reservoir for this virus. Possibly the 1918 Spanish Flu was transmitted likewise.
Maybe if we kept our hands off animals (and their flesh off our dinner tables) the world would be a safer place?
