COVID-19, the Novel Coronavirus currently ravaging the world population, is technically
the third major Coronavirus to present a serious threat to human health in the last twenty
years.
The previous two were SARS – severe acute respiratory syndrome – and MERS – Middle
East respiratory syndrome – both of which caused trouble for us in the early-to-mid-2000s.
Both of these were dangerous viruses, but they feel almost like a warm-up compared to
the devastation currently being caused by COVID-19.
Seeing as COVID seemingly took us by surprise, plenty of people are already nervously asking:
Is it possible that there could be an even worse virus out there that we don’t even
know about yet?
That’s why the recent discovery of six new coronaviruses in Myanmar bats is seen by some
as a cause for concern.
These new coronaviruses found in the bats in Myanmar were found as part of the US government-funded
PREDICT initiative – meant to detect diseases that may later become a threat to human health
– carried out by the Smithsonian’s Global Health Program scientists.
The scientists conducted studies in three locations in Myanmar, two of which were cave
systems where the local people are known to perform religious ceremonies and harvest natural
resources in close proximity to the local bats.
Anyone with a decent knowledge of zoology and epidemiology knows that this is risky
business.
Bats have always been a prime suspect for zoonotic diseases – Meaning: Pathogens that
originate in animals but can pass on to humans – thanks to their strong immune system,
which allows them to carry zoonotic diseases without being infected by them.
And zoonotic diseases are not to be messed with – studies have shown that these diseases
have been responsible for almost three quarters of infectious diseases in the last century
of human history, making them responsible for millions upon millions of deaths.
Scientists have estimated that there could be as many as 1.6 million undiscovered viruses
present in birds and mammals, we can only hope that most of these aren’t zoonotic.
As of 2013, bats were proven to carry over sixty zoonotic viruses, from rabies to Ebola
– and potentially many, many more undiscovered coronaviruses.
Even COVID-19 is thought to have originated in bats, though scientists note it could have
been passed to humans by an intermediary infection vector rather than direct bat-to-human infection.
The Smithsonian scientists have studied the Myanmar bats extensively between 2016 and
2018, for not only the impressive variety of bats, but also their close proximity to
the human locals.
Bat guano – otherwise known as excrement – makes an excellent fertilizer, so it’s
often used by local Myanmar farmers.
This, however, puts the people of Myanmar at a higher risk of infection than most.
Conducting this research wasn’t easy.
Scientists were forced to suit up in sterile full-body overalls, complete with masks, goggles,
boots, and gloves.
They then had the unenviable job of sneaking into the local cave systems in the dead of
night, setting up nets, and waiting to capture their subjects.
If the idea of sitting around in a creepy cave full of live bats doesn’t sound like
your idea of fun, the scientists would agree with you.
Many have described the work as “gruelling”, but worth it for the ultimate result.
They also scraped guano samples directly from the cave walls, which was probably considered
a more relaxing – if a little grosser – task.
The Smithsonian scientists studied over 464 bats from eleven different bat species, collecting
759 samples of saliva and guano with oral and rectal swabs – with these two substances
being the most common vectors for transmission.
They then analysed the samples’ genetic sequence and compared the results of their
tests to the genomes of known coronaviruses to find any potential similarities.
As it turned out, they were about to strike viral gold, as forty-eight of their samples
contained coronaviruses.
The scientists focused their study on three varieties of bat in particular: The Greater
Asiatic yellow house bat – also known as Scotophilus heathii, the wrinkle-lipped free-tailed
bat – also known as Chaerephon plicatus, and Horsfield's leaf-nosed bat – also known
as Hipposideros larvatus.
Between them, these bats were found to host strains of coronavirus known as PREDICT-CoV-90,
PREDICT-CoV-47, PREDICT-CoV-82, PREDICT-CoV-92, PREDICT-CoV-93, and PREDICT-CoV-96.
We don’t fully understand if any of these viral strains may mutate in the future and
present a threat to human health, which is why funding the continued research of projects
like PREDICT is so incredibly important.
Suzan Murray, the head of the Smithsonian's Global Health Program, has cited early detection
and research as one of the key factors in preventing outbreaks from ever becoming epidemics
and pandemics.
By studying animals in risk-prone areas, where humans and animals are in close proximity,
scientists and governments are able to remain aware of where the next problematic virus
might pop up.
As urban development spreads further into forests and jungles the world over, interaction
between people and animals is increasing, and with it, the chances of catching a zoonotic
pathogen.
It’s a humbling reminder that humans aren’t separate from the natural ecology of the places
they inhabit, and are still subject to a lot of the same threats faced by animals.
Interestingly, this is also a two-way street.
There have been concerns that humans infected with COVID-19 could spread the deadly infection
back into bats, decimating their more fragile population.
This fear has actually gotten so severe that the US Fish and Wildlife Service has issued
an advisory memo asking American bat biologists to cease their work for the time being due
to the potential risk of endangering their subjects with COVID-19 infection.
Other animals have also caught the disease from humans, such as the tiger infected with
COVID-19 in a New York zoo.
As stated earlier, it’s extremely unlikely that COVID-19 initially passed into humans
directly from bats, so ridiculous calls for bat extermination are as unwarranted as they
are cruel.
Back in the early 2000s, the SARS outbreak originated in horseshoe bats, but didn’t
pass into humans until it first infected civets – a small, cat-like tropical creature.
There’s still a lot of uncertainty around the initial vector that passed COVID-19 from
bats to human hosts.
Some have speculated the pangolin – a small, scaly anteater-like animal – but there isn’t
a conclusive answer on this.
Other potential suspects include cats, buffalo, sheep, pigeons, goat, and cattle.
The evolution from animal to human in the genetic code of COVID-19 could have occurred
in any of these intermediary species, and possibly even more.
One thing scientists are fairly certain about is that it’s likely the virus did indeed
make its evolutionary leap in the intermediary animal rather than the bat that first carried
it.
There isn’t actually any sense of certainty as to how COVID-19 first emerged.
While the bat is a safe assumption, scientists concede that this is only really speculation.
During the initial months of the disease’s spread, when it was mainly affecting China,
it was also speculated that the virus could have originated in one of the animals in a
Wuhan “wet market” – an open-air market for meat that uses live animals.
However, there’s no way of knowing if this really was the case, as the market – which
also allegedly dealt in illegal exotic meats – dispersed pretty quickly after it gained
national attention.
While it probably feels like COVID-19 has been with us for an eternity, we’ve only
even been aware of the virus since late December of last year.
There’s still a great deal of research required before we get anywhere near to truly understanding
this virus – and some facts, like its exact origin, may be lost to time entirely.
All we can do is rely on our scientists to find possible solutions through research and
experimentation.
Check out our other videos “What Is It Actually Like To Have COVID-19” and “What if the
COVID-19 Pandemic Lasts 18 Months or More?” for more information about our current crisis.