Posted on 10/02/2020 7:11:38 AM PDT by Roman_War_Criminal
Viruses jumping from animals to humans have been the starting point of numerous outbreaks, from Ebola to Zika.
Given the similarity of SARS-CoV-2 to coronaviruses found in bats, this probably marked the beginning of COVID-19 too.
We know that viruses have passed from animals to humans throughout history, and will continue to do so. But the factors that influence the geographical origin of these events is less clear, despite being highly important.
Knowing where they occur can help us understand the factors behind a virus crossing species, in particular, by looking at the traits of viruses circulating in the ecosystem where the jump happened.
But identifying a virus’s origin is sometimes difficult. Human movement is constant and wide-ranging, which means that the first case of a disease can be hundreds, if not thousands of miles away from where transmission into humans started.
Given this, where should we be looking for the virus that might cause the next epidemic?
Beyond Africa and Asia Generally, viruses emerge where humans and animals that carry viruses intersect. Repeated interaction between people, these animals or insects and the wider environment in which the virus circulates increases the opportunity for a jump across species. These jumps are believed to be rare, and probably happen due to a specific set of circumstances that cannot necessarily be predicted.
Humans are exposed to viruses all the time. Most of these exposures lead to a “dead-end infection”, where the virus isn’t passed on.
Occasionally, though, the virus may be able to replicate and be transmitted to a new host, or if vector-borne, to an insect that establishes a novel and functional transmission cycle.
This happens all over the world, though recent headline-grabbing outbreaks give the impression that viruses emerge in some places more than others. In particular, the seriousness of outbreaks such as Sars in Asia and Ebola in Africa makes it look like these are the only places where it happens. This isn’t the case.
For example, the Schmallenberg virus, which primarily infects livestock and causes spontaneous abortion in infected animals, recently appeared in Europe. And while we don’t hear much about viruses emerging from South America, it does happen.
The Venezuelan equine encephalitis virus and the Mayaro virus have repeatedly caused outbreaks in South and Central America. It’s only because these diseases haven’t spread beyond the Americas that they aren’t more widely known.
A further factor that has prevented the Mayaro virus from gaining more attention is that it has very similar symptoms to disease caused by another virus – chikungunya. It’s also often misdiagnosed as dengue fever, meaning the true number of Mayaro cases isn’t being reported.
This points to a wider issue, which is that most viruses initially cause very similar symptoms. In areas where dengue or malaria are endemic, most viral diseases are attributed to these infections, masking the appearance of new viruses until they become common – by which point they may have spread from their point of origin.
More effective and faster diagnostics are needed to help identify these sorts of novel diseases before they have a chance to shift into new transmission cycles.
Humans close to where a virus is endemic don’t always show evidence of it emerging, either. Through regular exposure to the virus they may not show any symptoms of infection. It may be only after the virus moves into an unexposed population that there are enough cases for it to be identified. In the highly connected world of today, this could be halfway around the globe.
We need to look at hosts If it’s not really feasible to determine where the next epidemic will start by simply looking at a map, then what should we do? Well, a better method is to try and understand the endemic transmission cycle of viruses – that is, to look at the animals and environments in which viruses replicate without causing human disease – and then work backwards.
Knowing what viruses are already out there in animals can help us trace the origins of human diseases when new outbreaks occur. This knowledge is critical to understanding the potential risks in different areas of the globe. It can also help us unpick what factors make it more likely that viruses will jump into humans.
For instance, with SARS-CoV-2 it was previous research into the transmission cycles of bat coronaviruses in China that helped identify these animals as the likely origin of the outbreak. This is now letting us investigate what it is about bats that means they’re so often involved in viruses crossing into humans.
It may be that the adaptation of coronaviruses to bats increases the likelihood that they can jump to other mammalian species, including humans. Equally, it could be that the physiology of bats makes them excellent virus carriers. However, other recent work suggests that viruses emerge more commonly from bats simply because there’s a high number of bat species, rather than bats themselves being an exceptional host.
Our understanding of the virus species present in bats and other species is only at its beginning – in fact, the study that helped trace the origins to SARS-CoV-2 to bats in China was recently halted.
If we’re serious about trying to predict what the next dangerous virus might be – and where it might come from – we need instead to be expanding this sort of work, not ending it.
In a street riot near you.....
Doesn’t matter where it starts. With international flights thousands of times a day, it will spread. Limit travel to and from basket case countries.
Bigger question is how many epidemics and pandemics are currently in progress and where are they globally?
COVID19 didn’t start from a bat, it came from the Chicom’s!
Plain and simple we should already be at war with those commie bastards!
My point is that the next “epidemic” will be a civil war.
Yep pandemics come and go.....
Here is a list of some that have occurred thru the ages.
20 of the worst epidemics and pandemics in history
https://www.livescience.com/worst-epidemics-and-pandemics-in-history.html
It’s a man made virus. It’s not natural. I had it and I can attest that is 100% lab made in China.
It will start in China. It always starts in China.
It will involve some hapless critters and the wet market.
When is the real question.
I figure in about two weeks.
a fool in paradise ~ Bigger question is how many epidemics and pandemics are currently in progress and where are they globally?Bring Out Your DeadI wouldn't discount the possibility that they have a new and improved deadly plague 'in the can' just waiting for the moment when the rest of the world is so throughly sick and tired of wearing masks that we will refuse to don them yet again for another "false" alarm.
spincaster ~ COVID19 didn’t start from a bat, it came from the Chicom’s!
Plain and simple we should already be at war with those commie bastards!We ARE already be at war with those commie bastards...
Post to me or FReep mail to be on/off the Bring Out Your Dead ping list.
The purpose of the “Bring Out Your Dead” ping list (formerly the “Ebola” ping list) is very early warning of emerging pandemics, as such it has a high false positive rate.
The false positive rate was 100%.
At some point we may well have a high mortality pandemic, and likely as not the “Bring Out Your Dead” threads will miss the beginning entirely.
*sigh* Such is life, and death...
Quarantine the sick. Protect the vulnerable. Free everyone else.
Whatever and whenever, I’m not participating. ;)
Good plan!
The FungYouTooFlu is man made and airborne. This will not go away as anyone with eyes can see. Someone once said live free or die and that looks like today’s options. At least for today.
Don’t know “where” the next will start, but a few months back Bill Gates said, chuckling, that the next wave in the Fall “will get your attention”.
Wash your hands
Don’t spit on the sidewalk
Stay home if you’re sick
Don’t tug on Superman’s cape...
“You Don’t Mess Around With Jim” by Jim Croce
Uptown got its hustlers
The Bowery got its bums
42nd Street got Big Jim Walker
He’s a pool-shootin’ son of a gun
Yeah, he big and dumb as a man can come
But he stronger than a country hoss
And when the bad folks all get together at night
You know they all call big Jim “Boss”, just because
And they say
You don’t tug on Superman’s cape
You don’t spit into the wind
You don’t pull the mask off that old Lone Ranger
And you don’t mess around with Jim
Well outta south Alabama come a country boy
He say I’m lookin’ for a man named Jim
I am a pool-shootin’ boy
My name’s Willie McCoy
But down home they call me Slim
Yeah I’m lookin’ for the king of 42nd Street
He drivin’ a drop top Cadillac
Last week he took all my money
And it may sound funny
But I come to get my money back
And everybody say Jack don’t you know
You don’t tug on Superman’s cape
You don’t spit into the wind
You don’t pull the mask off that old Lone Ranger
And you don’t mess around with Jim
Well a hush fell over the pool room
Jimmy come boppin’ in off the street
And when the cuttin’ was done
The only part that wasn’t bloody
Was the soles of the big man’s feet, ooh
And he was cut in about a hundred places
And he was shot in a couple more
And you better believe
They sung another kind of story
When big Jim hit the floor
Now they say
You don’t tug on Superman’s cape
You don’t spit into the wind
You don’t pull the mask off that old Lone Ranger
And you don’t mess around with Slim
Yeah, big Jim got his hat
Find out where it’s at
And it’s not hustlin’ people strange to you
Even if you do got a two-piece custom-made pool cue
Yeah you don’t tug on Superman’s cape
You don’t spit into the wind
You don’t pull the mask off the old Lone Ranger
And you don’t mess around with Slim
That too
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