We humans share ‘One Health’ with animals
ANIMAL health and human health are so intertwined that they need to be considered together. All living beings, animal and human, are just “life” in different forms. One Health is the concept that all species are directly connected. And COV
ID-19 has proven this in a way that none of us wanted to see. NOBODY should be surprised about the pandemic that has so dramatically changed all of our lives. For many years, scientists have been telling us that there has been a high risk of serious new human diseases emerging from the animal world. THIS does not mean that animals are “to blame”: far from it. If anything, humans are to blame for the way that we treat other species. But blame is pointless, and it’s more accurate to say that nature is to blame: new viruses have been appearing for thousands of years. MOST viruses live in balance with their hosts: causing low grade disease that allows the animals to carry on living, spreading the virus around. In fact, the most successful viruses show few symptoms and cause their host little to no harm. THAT’S why established human viruses would not cause a pandemic like this: it took a new virus, from which nobody is protected by immunity from vaccination or previous exposure. New viruses aren’t created out of thin air: much like humans evolved from apes, viruses evolve from older virus types. VIRUSES tend to be fussy about what species they infect. One obvious exception to this is rabies, which is easily able to infect multiple species: this is one of the reasons why the disease is dreaded so much. Many viruses are only able to infect one species. That’s why people don’t need to worry about picking up Parvovirus from dogs, or Cat
Flu from cats. The viruses that cause these serious diseases in our pets are unable to infect us, so we are safe. THE big new viral diseases affecting humans in recent decades - from Swine Flu, to Avian
Flu, to Ebola, then SARS (Severe Acute Respiratory Syndrome) in 2003, and now COVID-19 - all have one thing in common: they came from animals. THE background to each of these outbreaks has been that a virus has jumped from an animal species to humans. This jump is made possible through the virus mutating or evolving. This is part of the normal cycle of events in the virus world: minor changes happen all the time to viruses. Most often, the slightly mutated or evolved virus isn’t as successful at life as the original virus, and it dwindles away, never to be seen again. However once in a while, a virus may mutate in such a way that allows it to infect a different species such as humans. Again, usually when this happens, it isn’t a big deal: the mutated virus is unable to find a human to infect, and it fizzles way to nothing inside its animal host.
HOWEVER in random, unfortunate situations, the mutated virus finds a human to infect. With Avian and Swine flu, this was thought to be farmers in ultra-close contact with hens or pigs, breathing in dust and debris from intensively farmed animals. With Ebola, the causative virus originates in bats, and the cross-over was thought to be linked with humans killing and eating bats (bat soup is a popular delicacy in the area where it came from). And with COVID-19, the source, again, is thought to be bats, originating in a Chinese “wet market”. THIS has been discussed in detail in the media, and I have mentioned previously that I have had direct experience of Chinese live animal markets, visiting them many years ago when I was backpacking around the world as a young vet. The markets were not dissimilar to the old-style fruit and vegetable markets that we have all seen, whether in Ireland or other European countries. The big difference is that animals are sold as well: alive and dead. THERE was a traditional focus on meat being as fresh as possible: for this reason, the animals for sale were often alive, but were then slaughtered and butchered on the spot. This was understandable in a culture where refrigeration was a relatively new concept, and it was of prime importance to human health that food was fresh. The best guess at the origin of the COVID-19 virus is that a new mutated virus was in a bat that was slaughtered at the wet market: the bat blood would have contained virus particles and nearby humans would have been exposed to these, by direct contact at the time of slaughter, as well as afterwards if hands weren’t washed. Hence the first human infection happened. The virus thrived, causing pneumonia in that first person, who would have passed it on to people around them by coughing. The spread since then has been exponential and global, thanks to our contemporary penchant for worldwide travel.
THE stable door has now been slammed shut: in February the Chinese authorities banned the trade and consumption of wild animals. This is good news for many reasons, including ecology and welfare, as well as for human health in the future. But it’s too late for this pandemic: the viral horse had bolted, and we are now dealing with the terrible consequences.
So yes, animals were the origin of COVID-19. But it was not their fault.
I have written before about One Health, and I’ll write about it again in the future. Humans and animals: we are all on this one planet, in this One Life together.