Habitat Destruction Spreads Novel Diseases — Dare to Know
We promise not to bore or mislead you with advice about COVID-19. Find out why habitat destruction is the root cause of emerging infectious diseases.
I ran across this quote today from H.L. Mencken, “There is always a well-known solution to every human problem-neat, plausible and wrong. “ Mencken was one of those writers who made his living by saying clever but contrarian things.
Still, the quote seemed apt due to what we’re going through lately. Everyone seems to have a simple solution for our complex problem.
Judging by the experts, almost all of these simplistic solutions would do more harm than good. I’m not offering any opinions on how to cope with the ongoing pandemic.
AVOID MISLEADING OR, EVEN WORSE, BORING OUR READERS
Lots of qualified professionals with official jobs have explained all that. The best thing for someone like me to do is to learn and apply the guidelines. That way, I’ll avoid misleading or, even worse, boring our readers.
Instead, I’ll discuss something else about pandemics. Readers may have heard that the coronavirus came from a “Chinese wet market.”
People have told me that it came from eating germy bats. The truth is, not all of the initial patients even went to the wet market.
INFECTED PERSON AT “WET MARKET” SPREAD THEIR GERMS
If it started in the wet market, it’s because some infected person went there and spread their germs. DNA tests show that while COVID-19 may have started out in bats, it passed through other animal species before infecting humans.
It’s true that we’re going to see a lot more of these epidemics in the future but it’s not because of odd food habits. It also has nothing to do with nationality.
Associate Professor Thomas Gillespie from Emory University explains, “Pathogens do not respect species boundaries. I am not at all surprised about the coronavirus outbreak. The majority of pathogens are still to be discovered. We are at the very tip of the iceberg.”
ROOT CAUSE IS THAT WE KEEP INVADING WILD PLACES
It’s true that coronaviruses come from wild animal species. They’re what biologists call zoonotic. The root cause of them spreading from wild animals to humans is that we keep invading wild places and causing habitat destruction.
Professor Gillespie explains, “Major landscape changes are causing animals to lose habitats, which means species become crowded together and also come into greater contact with humans. Species that survive change are now moving and mixing with different animals and with humans.”
David Quammen, author of Spillover:Animal Infections and the Next Pandemic explained it this way in an opinion piece for the New York Times.
“WHEN THEY NEED A NEW HOST, OFTEN WE ARE IT”
“We cut the trees; we kill the animals or cage them and send them to markets. We disrupt ecosystems, and we shake viruses loose from their natural hosts. When that happens, they need a new host. Often, we are it.”
The underlying causes of all the recent pandemics are human activity and human development. Land conversion turning wildlife habitat into agricultural land releases unwanted microbes into our communities.
Emerging infectious diseases have been climbing since the 1940s. We’ve had 335 outbreaks over that time.
THREAT TO GLOBAL HEALTH, SECURITY AND ECONOMIES
Professor Kate Jones of University College London led the research that drew that conclusion. She says that zoonotic diseases are an “increasing and very significant threat to global health, security and economies.”
Professor Jones’ research shows that emerging infectious diseases peaked in the 1980s. That’s when we started seeing (you guessed it!) AIDS and HIV.
Habitat degradation also unleashed Ebola, Zika, Bird Flu, West Nile Virus, SARS and COVID-19. The Centers for Disease Control (CDC) tell us that roughly 75% of new diseases come from wild animals.
ROADS ATTRACT WRONG ELEMENT WHEN NOT PATROLLED
One of the worst drivers of habitat loss is road construction. We may need roads, but they attract the wrong element when they’re not patrolled properly.
Roads through natural habitats bring in illegal speculators, poachers, loggers and miners. Ninety-five percent of the forest destruction in the Amazon goes on within five kilometres of a road. Besides, most roads though there aren’t legal in the first place.
This also goes on in the Congo. Species extinction for many plants and animals there is a clear threat. Poachers have slaughtered roughly two-thirds of all forest elephants for their tusks.
POACHING TOOK OFF AFTER 50,000 KILOMETRES OF ROADS
The poaching took off after loggers built 50,000 kilometres of roads through the Congo. Mining, hunting and logging, legal or illegal, arrive by road.
Roads, urbanization and population growth all cause habitat destruction. This unleashes invasive species and exposes humans to native species. Professor Jones explains it this way.
“We are going into largely undisturbed places and being exposed more and more. We are creating habitats where viruses are transmitted more easily, and then we are surprised that we have new ones.”
“SPECIES LEFT ARE THE ONES WE GET DISEASES FROM”
Professor Jones studies how changes in the type of habitat raise the risk of disease. She warns us, “Destroy landscapes, and the species you are left with are the ones humans get the diseases from.”
Professor Gillespie noted that similar habitat fragmentation from subdivisions in the United States spreads Lyme Disease. As he put it, “Altering the ecosystem affects the complex cycle of the Lyme pathogen. People living close by are more likely to get bitten by a tick carrying Lyme bacteria.”
The research around how habitat destruction spreads disease is leading to a new field of science. It’s called planetary health.
NEW FIELD OF SCIENCE CALLED PLANETARY HEALTH
A leader in the new field is Distinguished Senior Scientist Richard Ostfeld of the Cary Institute of Ecosystem Studies. He challenges some of the old ideas about how disease spreads, saying:
“There’s misapprehension among scientists and the public that natural ecosystems are the source of threats to ourselves. It’s a mistake.
Nature poses threats, it is true, but it’s human activities that do the real damage. The health risks in a natural environment can be made much worse when we interfere with it.”
“THE MORE WE DISTURB HABITATS THE MORE DANGER WE ARE IN”
As for bats, Dr. Ostfeld had this to say, “Rodents and some bats thrive when we disrupt natural habitats. They are the most likely to promote transmissions. The more we disturb the forests and habitats the more danger we are in.”
As we can see, these new diseases don’t come from any one country. They also have nothing to do with peculiar diets or marketplaces.
The real cause is that no other animal has ever dominated the planet in such vast numbers or with such invasive technology. We’re causing all of this habitat destruction. Emerging infectious diseases are just one more reason for us to learn how to live sustainably on our planet.
This new field of planetary health shows a lot of promise. We’ll be following it throughout this current pandemic and beyond.
We always have more to learn if we dare to know.
Destroyed Habitat Creates the Perfect Conditions for Coronavirus to Emerge
We Made the Coronavirus Epidemic
Global Trends in Emerging Infectious Diseases
Discovery of a novel coronavirus associated with the recent pneumonia outbreak in humans and its potential bat origin
If Our Planet Had a Say, Here’s Where Future Roads Would Go
Coronavirus Fact Check
Mass Extinction Happening Again
Forest Elephants and Climate Change
Amazon Wildfires: 4 Things We Still Need to Know
Originally published at https://daretoknow.ca on March 26, 2020.