“Anything to do with bats, in theory, can expose yourself to potential viral transmission because we know bats carry so many viruses,” said Linfa Wang, who heads the emerging infectious disease program at Duke-National University of Singapore Medical School.
Bats contain the highest proportion of mammalian viruses that are likely to infect humans, according to research published in 2017 by disease ecologist Peter Daszak in the scientific journal Nature.
Still, very few bat viruses are ready to transmit directly to humans, said Wang, who has been studying bat origins of human viruses for decades and works with a group of researchers sometimes dubbed ‘The Bat Pack.’
“
Still, very few bat viruses are ready to transmit directly to humans, said Wang, who has been studying bat origins of human viruses for decades and works with a group of researchers sometimes dubbed ‘The Bat Pack.’
“I always say that if they could do that, then the human population would have been wiped out a long time ago because bats have been in existence for 80-to-100 million years — much older than humans,” he said.
I always say that if they could do that, then the human population would have been wiped out a long time ago because bats have been in existence for 80-to-100 million years — much older than humans,” he said.
Guano collectors usually enter the cave with long sleeved shirts and long pants, with a T-shirt wrapped around their head as makeshift cover — in contrast to how disease ecologists investigate caves in a full-body suit with masks and gloves. Although dry guano has low risk of infection, miners or cave visitors can potentially be exposed to viruses through the fresh saliva and urine of bats.
Source: Fortune.com
RaTG13 is the name, rank and serial number of an individual horseshoe bat of the species Rhinolophus affinis, or rather of a sample of its feces collected in 2013 in a cave in Yunnan, China. The sample was collected by hazmat-clad scientists from the Institute of Virology in Wuhan that year. Stored away and forgotten until January this year, the sample from the horseshoe bat contains the virus that causes Covid-19.
The scientists were mostly sampling a very similar species with slightly shorter wings, calledRhinolophus sinicus, in a successful search for the origin of the virus responsible for the SARS epidemic of 2002-03. That search had alarming implications, which were largely ignored.
In Shitou Cave, south of Kunming, the capital of Yunnan, they found viruses in the bats’ droppings and anal swabs that were more similar to human SARS than anything found in palm civets, the small mammals that until then were presumed to be the source of human infection. Back in the laboratory, they found that one of the viruses from bat droppings, called WIV1, could thrive in monkey and human cells specially engineered to activate the gene for ACE2 receptors, the lock to which a coronavirus’s spike protein can fit as a key. This suggested that people could catch SARS directly from a bat dropping.
Then in 2016, Ralph Baric and colleagues at the University of North Carolina at Chapel Hill showed that the same bat virus could infect live mice that had been engineered to express the human gene for the ACE2 receptor. The virus was “poised for human emergence,” as the title of Dr. Baric’s paper put it.
When Covid-19 broke out, attention focused on pangolins, mammals often called scaly anteaters. Early analyses of the pangolin version of the virus seemed to indicate it was even more closely related to the human version than the RaTG13 bat sample was. The illegal pangolin trade for traditional Chinese medicine brings people into contact with sick animals. Just over a year ago, 21 live Malayan pangolins destined for sale in China were intercepted by anti-smuggling officers in Guangdong. Despite the best efforts of a local wildlife rescue center, 16 died with swollen, flooded lungs, rich in coronaviruses.
The role of pangolins in the spread of Sars-CoV-2, the virus that causes Covid-19, remains unclear. A closer look at more of the Sars-CoV-2 genome, published last week by Maciej Boni at Penn State University and David Robertson at Glasgow University, together with Chinese and European colleagues, finds that human versions of the virus are more closely related to the RaTG13 horseshoe bat sample from the cave than they are to the known pangolin versions. It is not yet possible to tell whether the virus went from bat to pangolin to people, or from bat to pangolin and bat to people in parallel.
Source: wsj.com
Scientists have discovered six entirely new coronaviruses lurking in bats in Myanmar.
These viruses are in the same family as the SARS-CoV-2 virus that is currently spreading across the globe; but the researchers said the newbies aren't closely related genetically to SARS-CoV-2 or to the two other coronaviruses that cause severe infections in humans — severe acute respiratory syndrome (SARS), which caused the 2002-2003 pandemic, and Middle East respiratory syndrome (MERS).
The researchers discovered the viruses while surveying bats in Myanmar as part of a government-funded program called PREDICT to identify infectious diseases that have the potential to hop from animals to humans. And bats are prime suspects, as the mammals are thought to host thousands of yet-to-be-discovered coronaviruses. SARS-CoV-2, which causes the disease COVID-19, is also thought to have originated in bats before taking up residence in humans, possibly taking a detour through some intermediary host first.
Related: 13 coronavirus myths busted by science
Between 2016 and 2018, they collected hundreds of samples of saliva and guano (or bat poop) from 464 bats from at least 11 different species; they sampled at three locations in Myanmar where humans come into close contact with wildlife due to land use changes and recreational and cultural activities — such as guano harvesting for fertilizer.
"Two of these sites also featured popular cave systems where people were routinely exposed to bats through guano harvesting, religious practices and ecotourism," the researchers wrote in their study published online April 9 in the journal PLOS ONE.
The researchers analyzed genetic sequences from these samples and compared them with genomes of known coronaviruses. The new viruses were found in three bat species: the Greater Asiatic yellow house bat (Scotophilus heathii), where PREDICT-CoV-90 was found; the wrinkle-lipped free-tailed bat (Chaerephon plicatus), which was host to PREDICT-CoV-47 and -82; and Horsfield's leaf-nosed bat (Hipposideros larvatus), which carried PREDICT-CoV-92, -93 and -96.
Further research is needed to understand the potential for these six newfound viruses to move to other species and how they might impact human health, the researchers said.
Source: livescience.com
Bats contain the highest proportion of mammalian viruses that are likely to infect humans, according to research published in 2017 by disease ecologist Peter Daszak in the scientific journal Nature.
Still, very few bat viruses are ready to transmit directly to humans, said Wang, who has been studying bat origins of human viruses for decades and works with a group of researchers sometimes dubbed ‘The Bat Pack.’
“
Still, very few bat viruses are ready to transmit directly to humans, said Wang, who has been studying bat origins of human viruses for decades and works with a group of researchers sometimes dubbed ‘The Bat Pack.’
“I always say that if they could do that, then the human population would have been wiped out a long time ago because bats have been in existence for 80-to-100 million years — much older than humans,” he said.
I always say that if they could do that, then the human population would have been wiped out a long time ago because bats have been in existence for 80-to-100 million years — much older than humans,” he said.
Guano collectors usually enter the cave with long sleeved shirts and long pants, with a T-shirt wrapped around their head as makeshift cover — in contrast to how disease ecologists investigate caves in a full-body suit with masks and gloves. Although dry guano has low risk of infection, miners or cave visitors can potentially be exposed to viruses through the fresh saliva and urine of bats.
Source: Fortune.com
RaTG13 is the name, rank and serial number of an individual horseshoe bat of the species Rhinolophus affinis, or rather of a sample of its feces collected in 2013 in a cave in Yunnan, China. The sample was collected by hazmat-clad scientists from the Institute of Virology in Wuhan that year. Stored away and forgotten until January this year, the sample from the horseshoe bat contains the virus that causes Covid-19.
The scientists were mostly sampling a very similar species with slightly shorter wings, calledRhinolophus sinicus, in a successful search for the origin of the virus responsible for the SARS epidemic of 2002-03. That search had alarming implications, which were largely ignored.
In Shitou Cave, south of Kunming, the capital of Yunnan, they found viruses in the bats’ droppings and anal swabs that were more similar to human SARS than anything found in palm civets, the small mammals that until then were presumed to be the source of human infection. Back in the laboratory, they found that one of the viruses from bat droppings, called WIV1, could thrive in monkey and human cells specially engineered to activate the gene for ACE2 receptors, the lock to which a coronavirus’s spike protein can fit as a key. This suggested that people could catch SARS directly from a bat dropping.
Then in 2016, Ralph Baric and colleagues at the University of North Carolina at Chapel Hill showed that the same bat virus could infect live mice that had been engineered to express the human gene for the ACE2 receptor. The virus was “poised for human emergence,” as the title of Dr. Baric’s paper put it.
When Covid-19 broke out, attention focused on pangolins, mammals often called scaly anteaters. Early analyses of the pangolin version of the virus seemed to indicate it was even more closely related to the human version than the RaTG13 bat sample was. The illegal pangolin trade for traditional Chinese medicine brings people into contact with sick animals. Just over a year ago, 21 live Malayan pangolins destined for sale in China were intercepted by anti-smuggling officers in Guangdong. Despite the best efforts of a local wildlife rescue center, 16 died with swollen, flooded lungs, rich in coronaviruses.
The role of pangolins in the spread of Sars-CoV-2, the virus that causes Covid-19, remains unclear. A closer look at more of the Sars-CoV-2 genome, published last week by Maciej Boni at Penn State University and David Robertson at Glasgow University, together with Chinese and European colleagues, finds that human versions of the virus are more closely related to the RaTG13 horseshoe bat sample from the cave than they are to the known pangolin versions. It is not yet possible to tell whether the virus went from bat to pangolin to people, or from bat to pangolin and bat to people in parallel.
Source: wsj.com
Scientists have discovered six entirely new coronaviruses lurking in bats in Myanmar.
These viruses are in the same family as the SARS-CoV-2 virus that is currently spreading across the globe; but the researchers said the newbies aren't closely related genetically to SARS-CoV-2 or to the two other coronaviruses that cause severe infections in humans — severe acute respiratory syndrome (SARS), which caused the 2002-2003 pandemic, and Middle East respiratory syndrome (MERS).
The researchers discovered the viruses while surveying bats in Myanmar as part of a government-funded program called PREDICT to identify infectious diseases that have the potential to hop from animals to humans. And bats are prime suspects, as the mammals are thought to host thousands of yet-to-be-discovered coronaviruses. SARS-CoV-2, which causes the disease COVID-19, is also thought to have originated in bats before taking up residence in humans, possibly taking a detour through some intermediary host first.
Related: 13 coronavirus myths busted by science
Between 2016 and 2018, they collected hundreds of samples of saliva and guano (or bat poop) from 464 bats from at least 11 different species; they sampled at three locations in Myanmar where humans come into close contact with wildlife due to land use changes and recreational and cultural activities — such as guano harvesting for fertilizer.
"Two of these sites also featured popular cave systems where people were routinely exposed to bats through guano harvesting, religious practices and ecotourism," the researchers wrote in their study published online April 9 in the journal PLOS ONE.
The researchers analyzed genetic sequences from these samples and compared them with genomes of known coronaviruses. The new viruses were found in three bat species: the Greater Asiatic yellow house bat (Scotophilus heathii), where PREDICT-CoV-90 was found; the wrinkle-lipped free-tailed bat (Chaerephon plicatus), which was host to PREDICT-CoV-47 and -82; and Horsfield's leaf-nosed bat (Hipposideros larvatus), which carried PREDICT-CoV-92, -93 and -96.
Further research is needed to understand the potential for these six newfound viruses to move to other species and how they might impact human health, the researchers said.
Source: livescience.com
