Airborne Dust / Zoonosis / Land Use

This forum is to discuss general things concerning TSOI.
curncman
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Re: Airborne Dust / Zoonosis / Land Use

Post by curncman »

Thanks for posting great article on "data discrepancies in RaTG13 sequence" . This is first time I am reading about to RaTG13
trader32176
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Re: Airborne Dust / Zoonosis / Land Use

Post by trader32176 »

Curncman,
you're welcome !

The data is always moving us forward into new insights
trader32176
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Re: Airborne Dust / Zoonosis / Land Use

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Susceptibility of domestic pigs to SARS-CoV-2

9/14/20

https://www.news-medical.net/news/20200 ... CoV-2.aspx

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease (COVID-19), has infected over 28.9 million people and caused the death of more than 922,000 people worldwide. Originating in Wuhan, China, this novel virus causes mild to severe respiratory distress in infected human beings. Although the source of SARS-CoV-2 is still under investigation, it is said to have originated from bats. New reports continue to emerge that confirm the ability of SARS-CoV-2 to infect several new species of animals.

A recent study published on the preprint server bioRxiv* by scientists from Canadian Food Inspection Agency, Winnipeg, Manitoba, Canada; University of Manitoba, Canada; and Iowa State University, USA, sought to determine the susceptibility of domestic swine to SARS-CoV-2. Domestic swine is one of the most highly produced agricultural species that has the potential to impact public health significantly. A better understanding of the role played by domestic livestock in SARS-CoV-2 infection and transmission is critical to mitigating the risk of zoonotic transmission.

The authors say, “Determination of the susceptibility of pigs to SARS-CoV-2 is critical towards a One Health approach to managing the potential risk of zoonotic transmission.”

“Finally, we emphasize that no cases of domestic livestock have been documented by natural infection to date; however, the results of this study support further investigations into the role that animals may play in the maintenance and spread of SARS-CoV-2.”
trader32176
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Re: Airborne Dust / Zoonosis / Land Use

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Potential sea animal reservoirs for coronaviruses?

9/13/20

https://www.news-medical.net/news/20200 ... ruses.aspx

The COVID-19 pandemic has focused, yet again, intense research interest on coronaviruses, due to the high toll the novel coronavirus SARS-CoV-2 has taken on human life, health, economic well-being, and social activity.
A recent paper published on the server Preprints in September 2020 reviews what is known about this viral infection in water life.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to be present in all parts of the world, which has prompted the current exploration of its presence in aquatic life forms, which may act as reservoirs, passing it on while they themselves remain asymptomatic. The researchers made use of prior studies for this purpose.

Coronavirus Characteristics

Coronaviruses (CoVs) are viruses that cause epithelial infections of the gut, respiratory tract, as well as several other tissues. It is an RNA virus, with a nucleocapsid envelope and spike-like glycoproteins that form a crown, or corona, giving it its name. These spikes are essential for the infection since they are the part that engages with the host cell and makes infection possible.

While most CoVs are known to infect humans, bats, camels, and birds, all of which are terrestrial species. However, as part of the order Nidovirales, they can infect crustaceans, fish, and marine mammals as well, many of which are commercially important. Among them, the alpha-, beta-, gamma- and delta-coronaviruses infect the respiratory tract in both humans and non-humans and the gut in other organisms. This includes the betaCoVs SARS-CoV and MERS-CoV (Middle East Respiratory Syndrome).

Both these are zoonotic viruses, with animal reservoirs.
The CoVs also includes another subfamily containing two genera, Toro- and Bafini-virus, which have been found in Teleosts.

Coronaviruses in Water


Many researchers have investigated whether these viruses enter the water through sewage, whether treated or not. From the 1980s on, over a hundred pathogenic viruses have been found to be shed in human and animal feces, and thence to water bodies. This can lead to feco-oral transmission, allowing them to infect the digestive system and perpetuating the transmission chain. In fact, it is thought that 10 billion viruses may be present in a gram of feces.

Sewage contamination of water bodies is an ever-present possibility, especially with overflow or improper treatment before discharge. When bio-waste and hospital waste are also wrongly discharged into freshwater and marine environments, they can transfer these viruses into aquatic life.

Several studies have demonstrated the presence of SARS-CoV-2 in sewage from infected areas, and the virus persists for weeks in infectious form.

The infective virus can enter free-living organisms in the water and be transmitted to humans, triggering new outbreaks.
This risk must be evaluated, say the researchers.

Water-borne transmission is known to occur with alpha- and beta-CoVs, and the contaminated water may come into contact with the new host via swallowing, breathing of aerosolized droplets, through the skin or mucosal membranes, or aspiration into the lungs. CoVs are present in only minute concentrations in natural aquatic bodies, however.

Crustaceans

These organisms, also called shellfish, may harbor the virus in their exoskeleton. Still, since this is typically removed before eating, they have not been identified as potential agents of transmission to humans. Shrimps in Southeast and East Asia may harbor the yellow head virus.

The first Bafinivirus was found in white bream, but some Bafiniviruses colonize certain fish, such as the common carp, or the salmon, or bighead face fish. They have caused 70% mortality in fish farms, due to liver and kidney damage, with bleeding from the skin and into the abdomen. However, these are typically found in the gut of the host.

Since SARS-CoV-2 can tolerate a broader range of temperatures than earlier thought, between 4oC and 20oC in the air, it can live and replicate within fish, especially since they are ectothermic creatures with body temperature equalizing with the environment. Many such fish hosts have an adaptable body temperature. And the infection of marine mammals with Peneid shrimps that have a tropical habitat seems to indicate that this would not restrict future infection with the virus in these marine and aquatic creatures.

Waterfowl

Waterfowl seem to harbor the widest range of CoVs, about 96 varieties, if not more, from gamma- and delta-CoVs. Among the many waterfowl that feed with aquatic environments, ducks appear to be the group with the higher diversity. Some migratory birds have an expansive habitat and could, in theory, spread the virus effectively over a vast area. Research is required to explore the potential for CoV infection and transmission in these species.

Marine mammals

Seals in a Florida aquarium are known to have died of CoV-induced hemorrhagic pneumonia half a century ago, called the HSCoV (Harbor Seal coronavirus) outbreak. Other CoV infections in these species have involved viral bronchitis in beluga whales and bottlenose dolphins, both of which live in groups promoting viral spread. Thus, monitoring is essential to maintain the health of these species and to prevent onward transmission to other wild species, as well as to humans who come into contact with these animals in water parks or aquariums, in food markets, and when working with them in the wild.

Can CoV in Aquatic Life Infect Humans?

While there is no literature on the actual spread of aquatic CoVs to humans, respiratory viruses have been carried to humans from wild or captive animals, as in the H7N7 flu virus, which infected people via an autopsy of a seal, or through aerosols from a captive sneezing seal. The outcome, however, was conjunctivitis, rather than flu or respiratory disease. While many other viral infections have been detected in shellfish, involving human enteric viruses like hepatitis A virus, norovirus, rotavirus, and enterovirus, CoV outbreaks have not been recorded. H5N1 and A1 avian influenza viruses are associated with birds and are very contagious, spreading through infected duck meat and blood to humans. Ducks being very susceptible to CoVs, careful monitoring is required to make sure the same does not happen with these pathogens.

Current Recommendations

In the absence of recorded spread of SARSC-CoV-2 through aquatic organisms, the World Health Organization (WHO) and other health organizations have advised that wild animal markets should be avoided, while also ensuring that contact with farmed animals should be with due precautions. Meanwhile, further studies will occur to understand the effects of mutations and other genetic adaptations on changing routes of transmission between humans and animals, and the emergence of natural reservoirs.

The study sums up, “The diversity and presence of CoVs in aquatic organisms should be monitored to understand their infectious potential better and avoid future outbreaks in the wild, which eventually could also reach humans.”
trader32176
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Re: Airborne Dust / Zoonosis / Land Use

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Bioarchaeology research shows how infectious diseases may have spread 4000 years ago

9/21/20

https://www.news-medical.net/news/20200 ... s-ago.aspx

New bioarchaeology research from a University of Otago PhD candidate has shown how infectious diseases may have spread 4000 years ago, while highlighting the dangers of letting such diseases run rife.

Yaws - from the same bacteria species responsible for syphilis (Treponema pallidum) - is a childhood disease causing highly infectious skin lesions. It is spread via touch from person to person and, in advanced cases, can leave sufferers with severe bone disfigurement. While it is easily curable in its early stages, the bone disfigurements are irreversible.

The disease has been eradicated from much of the world but is still prevalent in the Western Pacific, affecting some 30,000 people. A previous global attempt to eradicate this tropical disease failed at the last hurdle in the 1950's and a new attempt was curtailed by the COVID-19 outbreak, University of Otago Department of Anatomy PhD candidate Melandri Vlok says.

Ms Vlok's PhD research uses archaeology to shed light on the spread of diseases when different human populations interact for the first time. Her specific interest is in what she calls the "friction zone", where ancient agricultural people met hunter gatherer people.

In 2018 she travelled to Vietnam to study skeletal remains from the Man Bac archaeological site. From the Ninh Bình Province in the north of the country, Man Bac was excavated in 2005 and 2007 and has delivered a treasure trove of information for archaeologists thanks to its role during the transition away from foraging to farming in Mainland Southeast Asia.

Now housed in Hanoi's Institute of Archaeology those remains are well-studied but had not been analyzed for evidence of yaws, Ms Vlok says.

Her supervisor at Otago, renowned bioarchaeologist Professor Hallie Buckley, had seen what she thought might be yaws on a photograph of Man Bac remains. Professor Buckley travelled with Ms Vlok and together with a passionate team of experts from Vietnam they confirmed their suspicions, Ms Vlok says. Later, Ms Vlok found a second example of the disease.

This was significant, as the Man Bac site dates back 4000 years. Till now, there was no strong evidence for yaws in prehistoric Asia.

Ms Vlok's research suggests yaws was introduced to hunter-gathers in present-day Vietnam by an agricultural population moving south from modern-day China. These hunter-gathers descended from the first people out of Africa and into Asia who also eventually inhabited New Guinea, the Solomon Islands and Australia.

The farmers had been in China for at least 9000 years but it wasn't until around 4000 years ago farming was introduced to Southeast Asia. It is possible this movement of people brought diseases, including yaws, at the same time.

Ms Vlok says the length of time the disease has existed in the region is relevant when addressing how hard it has been to eradicate.

"This matters, because knowing more about this disease and its evolution, it changes how we understand the relationship people have with it. It helps us understand why it's so difficult to eradicate. If it's been with us thousands of years it has probably developed to fit very well with humans."


This year's COVID-19 pandemic has focused people's attention on infectious diseases, and there are lessons to be learned from the past, Ms Vlok says.

" Archaeology like this is the only way to document how long a disease has been with us and been adapting to us. We understand with COVID-19 today how fantastic that disease is at adapting to humans. And Treponema has been with us for so much longer.

So, this shows us what happens when we don't take action with these diseases. It's a lesson of what infectious diseases can do to a population if you let them spread widely. It highlights the need to intervene, because sometimes these diseases are so good at adapting to us, at spreading between us."

-Melandri Vlok, PhD candidate, Department of Anatomy, University of Otago
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Re: Airborne Dust / Zoonosis / Land Use

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Bat and pangolin coronavirus structure sheds light on SARS-CoV-2 evolution

9/23/20

https://www.news-medical.net/news/20200 ... ution.aspx

Researchers at Tsinghua University, Beijing, have conducted a study providing possible new insights into the evolution and cross-species transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the agent responsible for the current coronavirus disease 2019 (COVID-19) pandemic.

The team's analysis of the viral spike proteins found on SARS-CoV-2 and two closely related coronaviruses revealed differences in their ability to bind and infect host cells that could explain why SARS-CoV-2 has evolved such a high infection capability.

The team identified important residues in the spike receptor-binding domains (RBDs) of SARS-CoV-2, the bat coronavirus RaTG13, and the pangolin coronavirus PCoV_GX that underlie the differences in activities of these spike proteins and their ability to bind to and infect host cells.

Xinquan Wang and colleagues suggest that five residues, in particular, are critical to the evolution of the SARS-CoV-2 spike RBD, due to the role they play in enabling tight binding to the human host cell receptor angiotensin-converting enzyme 2 (hACE2).

"These results collectively indicate that strong RBD-ACE2 binding and efficient RBD conformational sampling are required for the evolution of SARS-CoV-2 to gain highly efficient infection," writes the team.

A pre-print version of the paper is available on the serve bioRxiv*, while the article undergoes peer review.

Cross-species transmission of coronaviruses an ongoing threat


Animal-to-human (zoonotic transmission) of coronaviruses represents a significant threat to human health globally, as evidenced by the emergence of SARS-CoV-1, Middle East respiratory syndrome coronavirus (MERS-CoV), and SARS-CoV-2 over the last two decades.

Current evidence suggests that similarly to SARS-CoV-1 and MERS-CoV, SARS-CoV-2 probably originated in bats before evolving in intermediary hosts and then jumping to humans.

Coronavirus RaTG13, which was detected in the horseshoe bat, has been identified as sharing the most significant sequence identity (96.2%) with SARS-CoV-2, thereby pointing to the likely origin of SARS-CoV-2 in bats.

Another Malayan pangolin coronavirus (PCoV) identified in China's Guangxi (GX) is also closely related to SARS-CoV-2. Genome sequencing of this virus, PCoV_GX, has also indicated a high level of shared sequence identity (85.5%) with SARS-CoV-2.

The role the spike trimer plays in cross-species transmission

As the main viral structure enabling coronaviruses to infect host cells, the role the spike trimer protein plays in cross-species transmission and infection is of major interest to researchers.

"Coronavirus spike glycoproteins recognize their host cellular receptor and mediate membrane fusion for entry, thereby functioning as the most critical coronavirus protein in determining viral evolution and cross-species transmission," say Wang and colleagues.

Cryogenic electron microscopy (cryo-EM) studies have previously shown that similar to the spike trimer of SARS-CoV-1, the SARS-CoV-2 spike trimer needs to have at least one RBD in an "up" conformation in order to bind hACE2.

"Therefore, a spike trimer with all three RBDs' down' is in a receptor-binding inactive state, and the conformational change of at least one RBD from 'down' to 'up' switches the spike trimer to a receptor-binding active state," explain the researchers.

What did the current study involve?

Now, Wang and colleagues have determined the cryo-EM structures of the spike proteins from RaTG13 and PCoV_GX spikes and compared them to the spike of SARS-CoV-2.

The analysis revealed that the RBDs of RaTG13 and PCoV_GX spikes closely resembles that of the SARS-CoV-2 spike.

All three RBDs of the RaTG13 and PCoV_GX spike trimers were in the "down" conformation, suggesting that these RBDs tend to adopt the receptor-binding inactive state.

However, on performing surface plasmon resonance experiments, the researchers found that the PCoV_GX spike RBD exhibited a similar binding affinity for hACE2 to that of the SARS-CoV-2 spike RBD. At the same time, the RaTG13 RBD demonstrated far weaker hACE2 binding.

Variations at RBD residues accounted for the variation

Next, the team identified variations at six residues in the RBD that seemed to account for these differences in hACE2 binding between the three viruses.

The residues Y449, Q493, Q498, N501, and Y505 were particularly important since they clustered together to form a patch on the SARS-CoV-2 RBD that strongly interacted with hACE2.

The researchers also pinpointed amino acid changes at two positions (Y449 and Y505) that only occurred in the RaTG13 spike RBD and not the PCoV_GX spike RBD, which the researchers say may account for the weaker binding of hACE2 by RaTG13.

"We further propose that the patch containing Y449, Q493, Q498, N501, and Y505 plays a critical role in the evolution of the SARS-CoV-2 RBD, promoting especially tight binding to hACE2 and impacting the varying affinities observed between the RBD and ACE2 orthologs in wild and domestic animals," write Wang and colleagues.

The team also identified three N-linked glycosylation sites in the spike RBD of RaTG13 and PCoV_GX, one of which (N370) is not a glycosylation site in the spike RBD of SARS-CoV-2.

"The absence of glycans linked to N370 may contribute to the more flexible RBDs of the SARS-CoV-2 spike," suggest the researchers.

They say this hypothesis is supported by another study showing that mutation of N165 in SARS-CoV-2 gave rise to an increase in the "up" conformation of RBDs, suggesting that glycans serve as a conformational control element of the RBD.
What did the authors conclude?

"Based on all these results, we propose that the tight RBD-hACE2 binding we observed is the most critical factor in determining the varied cell-entry efficiency among RaTG13, PCoV_GX, and SARS-COV-2," say the researchers.

"This and the RBD' down' to 'up' conformational change are both required for the evolution of SARS-CoV-2 to gain highly efficient transmission capability," concludes the team.
trader32176
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Re: Airborne Dust / Zoonosis / Land Use

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Human-to-cat transmission of SARS-CoV-2 confirmed

9/24/20


https://www.news-medical.net/news/20200 ... irmed.aspx

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, belongs to the same species as the virus responsible for the SARS epidemic of 2003. The novel virus emerged in December 2019, in Wuhan, China, likely from bats, although some theories suggest that an intermediate species might have been involved.

Studies about the current COVID-19 pandemic have shown that SARS-CoV-2 infections can be transmitted from humans to domestic and non-domestic cats, dogs, and mink. Some in vivo experiments also show that while SARS-CoV-2 can infect ferrets, cats, and hamsters
, other animals such as ducks, pigs, and chickens are not susceptible to the virus.

Cat-to-cat transmission of SARS-CoV-2 has been experimentally proven, but little is known about the significance of this novel virus as a feline pathogen or its reverse zoonotic potential. The establishment of new animal reservoirs of SARS-CoV-2 could pose serious problems for human health in the future.

Currently, we do not have evidence of cat-to-human transmission or that dogs, cats, or other pets play any significant role in the epidemiology of SARS-CoV-2 in humans. Although it is clear that the current pandemic is driven by human-to-human transmission, it is important to determine if domestic animals can get infected and if they pose any risk to humans, especially those with comorbidities who are more likely to progress to severe disease.

Domestic animals could also serve as a viral reservoir, thus enabling continued transmission of the virus, even when human-to-human transmission slows down. Recent studies from Dutch mink farms that reported both mink-to-cat and mink-to-human transmission of SARS-CoV-2 agree with this scenario.

“Although the ongoing SARS-CoV-2 pandemic is driven by human-to-human transmission, concerns have been raised that other species might have the potential to play a role by becoming a new reservoir for the virus.”

In a study published on the preprint server bioRxiv,* a team of researchers from the University of Glasgow used a combination of lab techniques to show that two domestic cats from households with positive COVID-19 cases showing symptoms of mild to severe respiratory disease were infected with SARS-CoV-2.

Feline lung tissue tested positive for SARS-CoV-2 antigen and RNA


Two cats from different households in the UK with COVID-19 infection were studied using immunofluorescence, reverse transcriptase quantitative PCR, in situ hybridization, and viral genome sequencing. The lung tissue of cat 1 collected post-mortem showed pathological and histological findings consistent with viral pneumonia and also tested positive for SARS-CoV-2 RNA and antigens.

An oropharyngeal swab from cat 2 had viral RNA, and the cat showed signs of rhinitis and conjunctivitis. High throughput sequencing of the virus collected from cat 2 showed that the feline viral genome had 5 single nucleotide polymorphisms compared to the closest UK human SARS-CoV-2 sequence. A study comparing the viral genome from cat 2 with 9 other cat-derived SARS-CoV-2 sequences from various parts of the world showed no shared mutations.

The findings of the team confirmed that human-to-cat SARS-CoV-2 transmission is possible and can cause signs of respiratory disease in cats.

Findings highlight the need for a One Health approach

Previous reports of human-to-pet transmission of the SARS-CoV-2 virus have been sporadic might be because animal testing is limited. These reports underestimate the actual frequency of human-to-pet transmission. Reverse zoonotic transmission of SARS-CoV-2 represents a comparatively low risk to animal or public health in areas where transmission from human to human remains high.

Based on these findings of the study, the University of Glasgow team concluded that human-to-cat transmission of SARS-CoV-2 virus happened in the UK during the COVID-19 pandemic, with the cats developing mild to severe respiratory disease. The findings provide crucial insights into the management of cats by people who are at risk of developing severe disease.

Although we currently do not have evidence to show that domestic cats have any role in the epidemiology of the COVID-19, a better understanding of human-to-cat transmission mechanisms is possible only by monitoring cats in COVID-19-infected househ

“It will be important to investigate whether cat-to-human transmission is possible or likely, and to determine the duration of virus shedding and the level of contact with humans that is required for transmission to occur.”

The researchers feel that keeping in mind the versatility of the novel coronavirus, it is crucial to monitor cat-to-cat, human-to-cat, and cat-to-human transmission of the virus. The two reverse zoonotic infections reported in this study emphasize the need for a One Health approach between public health and veterinary organizations.
trader32176
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Re: Airborne Dust / Zoonosis / Land Use

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Tufts University to lead $100 million program to address threats posed by zoonotic viral diseases

9/30/20

https://www.news-medical.net/news/20200 ... eases.aspx

Tufts University will lead a $100 million, five-year program to understand and address threats posed by zoonotic viral diseases that can "spill over" from animals to humans, such as SARS-CoV-2, in an effort to reduce risk of infection, amplification, and spread, the United States Agency for International Development (USAID) announced today.

Strategies to Prevent Spillover (STOP Spillover), which builds on Tufts' deep expertise in One Health (the interrelated health of humans, animals, and the environment) and a number of related fields, will involve wildlife and human disease experts from both the university and organizations across the globe.

The program aims to enhance the capacity of local, national, and regional institutions in countries across Africa and Asia to understand factors that contribute to the risk of zoonotic spillover; develop and implement measures to reduce early risk of spillover and spread; and quickly identify and respond to spillover events.

" The transmission of zoonotic viral diseases to humans can cost lives, disrupt economies, and create lasting human health and societal problems, as we've seen most recently with the impact of COVID-19."

-Deborah T. Kochevar, STOP Spillover program director and a faculty member at Tufts

"Viral zoonotic disease outbreaks are becoming increasingly frequent. In our approach, it is not enough to know what to do to reduce viral spillover risks. We must also work with partners to institutionalize knowledge in existing systems, adapt learning to the local context, and continuously expand upon newfound expertise," she added.

STOP Spillover will be implemented by Tufts University and a consortium of wildlife and human disease experts that includes: the Africa One Health University Network; Broad Institute of the Massachusetts Institute of Technology (MIT) and Harvard University; Humanitarian OpenStreetMap Team; International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b); Internews; JSI Research and Training Institute, Inc.; Southeast Asia One Health University Network; Tetra Tech ARD; the University of California, Los Angeles; the University of Glasgow Institute of Biodiversity, Animal Health, and Comparative Medicine; the Global Center for Health Security at the University of Nebraska Medical Center; and the University of Washington Institute for Risk Analysis and Risk Communication.

The Tufts University consortium will build on previous USAID Emerging Pandemic Threats One Health programs to include characterization of risks and development of behavior-change interventions based on environmental, ecological, gender, behavioral, socio-cultural, economic and political factors.

The program leverages expertise from across Tufts' schools in infectious-disease forecasting, surveillance, prevention, and eradication; food and water safety and risk reduction; social behavioral change; global health diplomacy; and One Health programming and education.

"Part of our mission at Tufts is to make the world a better place, and with this initiative, Tufts and its many coalition partners will make a lasting, positive impact on global health," said Anthony P. Monaco, the university's president.

The Tufts schools and centers involved in the program include Cummings School of Veterinary Medicine at Tufts University, the Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy, Tufts University School of Medicine, The Fletcher School, the Feinstein International Center, and the School of Engineering.
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Re: Airborne Dust / Zoonosis / Land Use

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Thousands of Minks Dead as COVID Outbreak Escalates on Utah Farms

10/2/20


https://khn.org/news/thousands-of-minks ... tah-farms/

Thousands of minks at Utah fur farms have died because of the coronavirus in the past 10 days, forcing nine sites in three counties to quarantine, but the state veterinarian said people don’t appear to be at risk from the outbreak.

The COVID-19 infections likely were spread from workers at the mink ranches to the animals, with no sign so far that the animals are spreading it to humans
, said Dr. Dean Taylor, the state veterinarian, who is investigating the outbreak.

“We genuinely don’t feel like there is much of a risk going from the mink to the people,” he said Thursday.

Between 7,000 and 8,000 minks have died since the disease swept through the ranches that produce the animals, valued for their luxurious pelts. So far, no animals in Utah have been euthanized because of the disease, and it doesn’t appear to be necessary, Taylor said.

Fur from the dead infected animals will be processed to remove any traces of the virus and then used for coats and other garments, according to Fur Commission USA, a mink farming trade group. The U.S. produces more than 3 million mink pelts each year.

Taylor declined to name the farms or the counties where the affected minks were found.

With minks, as with humans, COVID-19 is less deadly for the young.

“It’s going through the breeding colonies and wiping out the older mink and leaving the younger mink unscathed,” Taylor said. Most of the deaths have been in minks between the ages of 1 and 4 years.

In addition to the minks, more than 50 animals in the U.S. had tested positive for the coronavirus as of Sept. 2, according to the U.S. Department of Agriculture. The infections have been detected in pet cats and dogs, as well as lions and tigers at a New York zoo.


Minks seem particularly susceptible to COVID-19, likely because of a protein in their lungs, the ACE2 receptor, which binds to the virus and appears to predict vulnerability to the infection, according to Wageningen University & Research in the Netherlands. Humans also have this protein in their lungs.

The COVID outbreak in Utah has surged since mid-August, when the first cases of the disease in the animals were confirmed by the USDA.

Minks were discovered to be susceptible to the SARS-CoV-2 virus, which causes COVID-19, in April, after outbreaks at several farms in the Netherlands, followed by outbreaks in Denmark and Spain. More than 1 million animals were culled in those countries, according to the Associated Press.

Several workers at the Utah mink farms have tested positive for COVID-19, including some who had no symptoms.

“Some of our mink ranchers have more than one facility, and that’s probably how it spread,” Taylor said.

A study in the Netherlands found that the virus appeared to jump back and forth between people and minks, but the data so far remains limited.

After the initial U.S. cases were confirmed, mink farms across Utah and the rest of the country implemented strict measures to prevent the disease from spreading, such as restricting access, conducting health checks on workers and disinfecting surfaces. The USDA and the Centers for Disease Control and Prevention have issued guidelines for farmed minks and other mustelids, a family of animals that also includes weasels and badgers.

“Obviously, it’s very concerning to have a species that is this susceptible with this high of a death rate,” Taylor said.

The outbreak has led to the quarantine of a quarter of Utah’s three dozen mink ranches and raised concerns across the state, said Clayton Beckstead, regional manager for the Utah Farm Bureau and a fourth-generation mink farmer.

“We’re certainly worried, but I think everybody’s taking pretty extreme biosecurity measures,” said Beckstead, whose own farm has not been affected.

Utah is one of the nation’s top mink producers. Overall, there are 245 fur farms in 22 states, part of an industry valued at $82.6 million a year, according to Fur Commission USA.

Investigating an outbreak of a novel virus in a new species is “daunting,” Taylor said.

“We’re learning as quick as we can,” he said. “We’re scrambling to help these animals and protect this industry.”
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Re: Airborne Dust / Zoonosis / Land Use

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More evidence Pangolin not intermediary in transmission of SARS-CoV-2 to humans

10/4/20

https://www.news-medical.net/news/20201 ... umans.aspx

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent for the current coronavirus disease (COVID-19) pandemic that has affected more than 35 million people and caused more than 1 million global deaths to date. The unprecedented repercussions of the pandemic have forced scientists to study the virus and its mechanism of infection closely in order to find a way to contain the spread of this virus through vaccination or treat affected people with effective therapeutic strategies that will help bring down the death rate.

Many of these efforts are focused on identifying the intermediate animal that is potentially involved in the transmission of the SARS-CoV-2 virus to humans. Several works found evidence for pangolin being the intermediary between the virus and humans based on the presence of virus related to SARS-CoV-2 in Malayan pangolins, ACE2 receptor polymorphism, and the similarities in sequence between the receptor-binding domain (RBD) of pangolin and human Sarbecoviruses.

However, some studies later reported that the binding affinity of the pangolin ACE2 receptor for the RBD of the virus is low. In a recent paper published in the journal Infection, Genetics and Evolution, researchers from the University of Barcelona, Spain; Xiamen University, China; and IHU-Méditerranée Infection and CNRS, France, provided more evidence to prove why pangolin cannot be the intermediate animal in SARS-CoV-2 transmission to humans.

The team proposed a different model named the ‘circulation model’ to illustrate how SARS-CoV-2-related coronaviruses could have circulated in different species, including humans, before COVID-19 emerged.

While many previous studies indicated that bats and pangolins were the culprits in COVID-19 transmission to humans, none of the studies clarified the actual role of these animals in the emergence of the COVID-19 pandemic
. The SARS-CoV-2 virus is suspected of having emerged from bats and was said to be closely related to the Sarbecoviruses MN996532_raTG13 and RmYN02 from the Chinese horseshoe bats Rhinolophus affinis and Rhinolophus malayanus, respectively.

Genomic analysis shows SARS-CoV-2 has been circulating in bats for many decades

The findings of this study did not agree with the currently proposed spillover model for zoonotic emergence. Also, the in-depth genomic analysis failed to support recombination in SARS-CoV-2 and showed that it has been circulating in bats for several decades now. Moreover, the drawback of metagenomic analyses that some previous studies performed is that there is not enough evidence to show that different parts come from the same virus and the recombinants came from artifactual assembly mosaics.

The SARS-CoV-2 spike protein S1 binds to the human ACE2 molecules on the cell surface. The analysis of ACE2 3D structures indicated that the amino acids found in the 30–41, 82–93, and 353–358 regions play a key role in interactions with the viral S1 spike protein. This set off a series of in silico analyses of ACE2 polymorphism that aimed at predicting which putative intermediate host animal might bind best to the ACE2 receptor so as to capture a SARS-CoV-2-like virus that is transmissible to humans.

Other than pangolin, the virus was shown to bind to the ACE2 receptor from a host of animals, including Chinese horseshoe bats, cats, civets, turtles, monkeys, ferrets, dogs, Chinese hamsters, cows, buffaloes, sheep, swine, and pigeons. According to the researchers, the virus does not preadapt to the host; instead, there is a host-driven selection of viruses post-exposure that can evade immune surveillance. The virus is already present in humans or animal species close to humans. A random event like a mutation suddenly makes it pathogenic or more invasive.

“According to the circulation model, what really prepares the ground for the epidemic is simply an accidental event, i.e., a mutation, recombination or reassortment in the virus genome.”

Circulation model puts focus back on human activities

The authors feel that the actual triggers for epidemics and pandemics lie in the organization of the society and human/animal contacts, and amplification loops offered by the human society, such as land conversion, contacts, markets, mobility, and international trade.

According to the researchers, a significant positive aspect of the circulation model is that the focus of the model is on human activities and not wildlife, and if we want to prevent future pandemics like these, we must reconsider the manner in which we interact with nature. They concluded that bats, pangolins, and other animals are not responsible for the epidemics or pandemics humans are facing right now. Blaming such infectious diseases on zoonotic emergence caused by wildlife may only result in unnecessary culling and mass slaughter leading to loss of biodiversity.
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