Airborne Dust / Zoonosis / Land Use

This forum is to discuss general things concerning TSOI.
Posts: 2723
Joined: Fri Jun 26, 2020 5:22 am

Re: Airborne Dust / Zoonosis / Land Use

Post by trader32176 »

Denmark announces new coronavirus restrictions amid mink-related outbreak

11/6/20 ... index.html

The Danish Government has announced new restrictions in seven municipalities after scientists there identified a mutated strain of coronavirus linked to the mink population.

According to the government, the mutated form of the virus has been passed back to humans.

Under the new restrictions, restaurants, cafes and pubs are to close from Saturday -- with an exception for food outlets selling takeaways. Indoor sporting venues -- including gyms --are also being shut, as well as cultural centers, including theaters, cinemas, museums, music venues and libraries.

The government has also announced it is shutting down public transport in the affected municipalities, with the exception of school buses.

The municipalities are Hjorring, Frederikshavn, Bronderslev, Jammerbugt, Thisted, Vesthimmerland and laeso.

The Danish Government is encouraging people in these regions to avoid travel outside their area, and to limit contact with others.

Under the new rules, public gatherings will be further restricted with gatherings of 500 people at seated events now cancelled. Gatherings of 50 people at sporting events or at children's activities is also cancelled.

Everyone living in the affected municipalities is encouraged to get tested while the new measures are in force. People with links to mink farm operations are being encouraged to be tested every 3-4 days.
Posts: 2723
Joined: Fri Jun 26, 2020 5:22 am

Re: Airborne Dust / Zoonosis / Land Use

Post by trader32176 »

Europe tries to shut down new coronavirus strain from Danish mink farms

11/9/20 ... farms.html

Key Points :

Last week, Danish health authorities raised the alarm over a mutant form of the coronavirus that arose in mink farms and has spread to humans.

Denmark’s State Serum Institute has warned the mutant virus could have potentially “serious consequences” for a future Covid-19 vaccine.

The U.K. and Ireland have responded to the outbreak with tougher public health measures.

LONDON — The discovery of a new coronavirus strain on Danish mink farms has led to the introduction of strict public health measures in the north of the country, with other European nations also responding to the outbreak.

It comes after a warning from Denmark’s national authority for the control of infectious disease, the State Serum Institute, that if the mutant virus were to spread internationally it could have potentially “serious consequences” for a future Covid-19 vaccine.

More than a quarter of a million people in northern Denmark went into lockdown on Friday, with citizens urged to get tested after Covid-19 infections were reported among the mink population in that region.

Restaurants across seven municipalities were ordered to close from Saturday, and schools from fifth grade and above were required to switch to remote learning from Monday.

Elsewhere, the U.K. government implemented stricter rules for arrivals from Denmark. Freight drivers who have been in or travelled through Denmark in the last 14 days, and who are not residents of the U.K., will now be refused entry to Britain. All passenger vessels and accompanying freight from Denmark will also be halted.

In Ireland, passengers arriving from the Scandinavian country have been told to take extra precautions to contain the spread of the newly-discovered coronavirus strain.

The Irish government has said people should restrict their movements for 14 days after entering the country from Denmark, even if they are visiting for an “essential” purpose.

What do we know about this new Covid strain?

Last week, Danish health authorities raised the alarm over a mutant form of the coronavirus that arose in mink farms and has spread to humans.

Prime Minister Mette Frederiksen described the situation as “very, very serious,” and ordered the country’s mink farms to cull all 15 million minks in a move designed to reduce the risk of the animals re-transmitting the strain of the coronavirus to humans.

Data from animal rights group Humane Society International puts Denmark as the world’s second-largest exporter of mink fur, behind China. It says Denmark accounted for roughly half of all of the 35 million mink farmed in Europe in 2018.

Since June, 214 human cases of Covid-19 have been identified in Denmark with variants associated with the farmed minks, the WHO said, including 12 cases with a unique variant, reported on Nov. 5.

All of these 12 cases were found to have originated in North Jutland, Denmark, and the people infected ranged in age from 7 to 79-years-old.

The WHO said initial observations suggested that the clinical presentation, severity and transmission among those infected were similar to that of other circulating coronavirus strains.

The WHO has since launched a review of biosecurity measures in mink farms across the globe.

Too early to ‘come to any conclusions’

The coronavirus is constantly evolving, and, to date, there is no evidence to suggest the mutation identified among Danish mink farms poses an increased danger to people.

As of Monday morning, more than 50.3 million people were reported to have contracted Covid-19 worldwide, with 1.25 million related deaths, according to data compiled by Johns Hopkins University.

Drugmakers and research centers are scrambling to deliver a safe and effective vaccine in an attempt to bring an end to the coronavirus pandemic.

Dr. Mike Ryan, executive director of the WHO’s health emergencies program, said on Friday that it was “a long, long way away” from understanding whether the mutation of the virus could have any implications for diagnostics or vaccines.

The WHO’s chief scientist, Dr. Soumya Swaminathan, agreed.

“I think that we need to wait and see what the implications are, but I don’t think we should come to any conclusions about whether this particular mutation is going to impact vaccine efficacy or not,” Swaminathan said on Friday.

“We don’t have any evidence at the moment that it would. But we will update you as we get more information.”
Posts: 2723
Joined: Fri Jun 26, 2020 5:22 am

Re: Airborne Dust / Zoonosis / Land Use

Post by trader32176 »

Cats shed SARS-CoV-2 RNA for a shorter duration compared to humans, study finds

11/8/20 ... finds.aspx

Since the emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes the coronavirus disease 2019 (COVID-19), there have been numerous reports of pets becoming infected. Both dogs and cats have been observed to exhibit symptoms of infection.

A new study by researchers at the University of Technology Sydney, the University of Sydney, the Icahn School of Medicine at Mount Sinai, New York, and the Universidad de Chile shows that infected cats have shorter shedding of SARS-CoV-2 RNA compared to their human owners. The results highlight a need for large-scale epidemiological analysis of the SARS-CoV-2 infection dynamics to develop preventive measures in both humans and their pets.

The study

The coronavirus pandemic stemmed from a localized outbreak in Wuhan City, China, where its first cases appeared in December 2019. From there, the SARS-CoV-2 has continued to spread across the globe, infecting over 48 million people. Early in the pandemic, scientists tied cross-species transmission between humans and an unknown animal reservoir to the spread of the virus.

As the pandemic evolved, scientists have found a growing body of proof that the virus can infect companion animals or pets, as well as other animal species.

So far, there have been cases reported to the World Organization for Animal Health (OIE) and the United States Department of Agriculture. These include 14 cases among dogs in the United States (US), Japan, and Hong Kong, and 25 cases in cats in Hong Kong, the US, Germany, Belgium, Russia, Spain and the United Kingdom.

Apart from domesticated animals or pets, some cases in farmed animals and zoo animals were also reported. Cases of SARS-CoV-2 in farmed milk were reported in the Netherlands, the US, Spain and Denmark. Tigers and lions have also been infected in a New York zoo.

In some studies, dogs have been experimentally infected with SARS-CoV-2 and showed low viral loads. This could mean that they do not transmit the virus to other dogs. Among domesticated animals, it was shown that mustelids and felids are more vulnerable to coronavirus infection than canines.

In the current study, which appeared on the preprint server medRxiv*, the team conducted active surveillance in Santiago City, Chile, starting in May to determine the possibility of infection in companion animals in households where people tested positive for SARS-CoV-2.

The team described the infection in a household of two human adults and three cats using real-time reverse transcription-polymerase chain reaction (RT-PCR) tests and enzyme-linked immunosorbent assay (ELISA) tests, viral sequencing, and viral isolation.

What the study found

To assess the infection of the humans and cats, the team conducted clinical observations for symptoms of COVID-19 and performed serological testing (which looks for the presence of antibodies in the blood).

The humans were infected first, and after several of the cats consecutively developed respiratory symptoms and tested positive. All cats excreted detectable SARS-CoV-2 RNA for a shorter duration than humans, and the viral sequences confirmed the human to cat transmission.

The study’s findings highlight that SARS-CoV-2 can be transmitted between humans and cats living in the same household. The virus can spread to animals by direct or indirect contact with contaminated surfaces or airborne particles.

The study’s findings of positive SARS-CoV-2 RNA detection in nasal samples and fecal samples in the three cats support recommendations to prevent close contact with pets when someone in the family is infected with COVID-19.

“The findings presented here show that cats seemingly have different and shorter patterns of excretion for SARS-CoV-2 RNA compared to humans. These results highlight a need for large-scale epidemiological analysis of SARS-CoV-2 infection dynamics to support the establishment of preventive measures in real-life human-animal relationships,” the team recommended.
COVID-19 spread

The spread of COVID-19 into animals also shows how vast the transmission of the virus can be. To date, there are over 48 million cases of COVID-19 across the globe. Of these, 1.22 million have already died due to the infection.

The United States reports the highest number of cases, topping over 9.48 million. India and Brazil trail behind with over 8.31 million and 5.59 million cases, respectively.

Since lockdown measures were lifted in most countries, it is important to continue implementing infection control measures to prevent skyrocketing cases. Health experts still reiterate the importance of regular hand hygiene, social distancing, and universal masking.

*Important Notice

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Journal reference:

Ramirez, V., Brito, B., Aguero, B., Berrios, F. et al. (2020). A household case evidences shorter shedding of SARS-CoV-2 in naturally infected cats compared to their human owners. medRxiv. doi:, ... 20220608v1
Posts: 2723
Joined: Fri Jun 26, 2020 5:22 am

Re: Airborne Dust / Zoonosis / Land Use

Post by trader32176 »

Rhesus monkeys and cats potential spillover reservoirs for COVID-19 virus

11/12/20 ... virus.aspx

A team of researchers from Switzerland, Costa Rica and Germany has conducted a study showing which animal species could potentially serve as spillback reservoirs of severe acute repertory syndrome coronavirus 2 (SARS-CoV-2) – the agent that causes coronavirus disease 2019 (COVID-19).

Using an in vitro airway epithelial cell (AEC) culture repository composed of various domestic, livestock, and wild animal species, the team found that SARS-CoV-2 only replicated efficiently in cultures grown from two species - the rhesus monkey and the cat.

“This is the first study employing an in vitro AEC culture repository composed of various domestic and wildlife animal species to assess the potential intermediate and spillback host reservoir spectrum of SARS-CoV-2,” say the researchers.

Whole-genome sequencing found no evidence to suggest that the predominant SARS-CoV-2 strain currently circulating the globe (the D614G variant) had undergone mutational adaptation to be able to infect the rhesus macaque and cat.

“This highlights that the currently circulating SARS-CoV-2 D614G variant can productively infect rhesus macaque and cat airway epithelial cells,” write Ronald Dijkman from the University of Bern and colleagues from Justus Liebig University Giessen, the Berlin Institute of Health and the University of Costa Rica.

Close surveillance of cats, monkeys and closely-related species is warranted to understand these species as potential spillback reservoirs for the virus, they say.

A preprint version of the paper is available on the server bioRxiv*, while the article undergoes peer review.

The potential for human-to-animal spillover events

Although humans are currently considered the main source of SARS-CoV-2 transmission, the zoonotic origin, intermediate host species and potential spillback host reservoirs are not yet known.

Several studies have indicated that SARS-CoV-2 can spillover from humans to other animal species.

“These events are likely driven by close human-animal interactions and the conservation of crucial receptor binding motif (RBM) residues in the angiotensin-converting enzyme 2 (ACE2) orthologues, potentially facilitating SARS-CoV-2 entry,” suggest Dijkman and colleagues.

The RBM is the main region within the receptor-binding domain of SARS-COV-2 that recognizes and attaches to the human host cell receptor ACE2.

“This highlights the need to assess the potential host spectrum for SARS-CoV-2 in order to support current pandemic mitigation strategies,” says the team.

Historically, such experiments have been limited regarding the availability and diversity of animal models, housing facilities, and ethical approval, with socioemotional ethical constraints posing a particular problem in the case of companion animals and non-human primates.

Testing susceptibility to SARS-CoV-2 in 12 animal species

Now, Dijkman and team have assessed SARS-CoV-2 Susceptibility in 12 mammalian species by reproducing the initial stages of infection in well-differentiated AEC cultures reconstituted from tracheobronchial epithelial tissue taken from the animals.

By using this controlled in vitro model, the team could comply with the “reduction, replacement, refinement” (3R) principle that is applied in animal studies, while circumventing ethical and experimental constraints.

The researchers obtained post-mortem tracheobronchial airway tissue from companion animals (cat, dog), candidate animal models (rhesus macaque, ferret, and rabbit), livestock (pig, cattle, goat, llama, camel) and two bat species.

Well-differentiated AEC cultures were established for each species and then inoculated with a SARS-CoV-2 isolate (SARS-CoV-2/München-1.1/2020/929) that represents the currently circulating D614G variant.

The virus only replicated efficiently in the rhesus macaque and cat

The researchers found that only tracheobronchial cells from the rhesus macaque and cat supported efficient replication of SARS-CoV-2.

The team observed a progressive 4-log fold increase in viral RNA load at 72- and 96-hours post-infection in the rhesus macaque and cat AEC cultures, while AEC cultures from the remaining species showed either a continuous or decreasing viral RNA load.

To test whether this observed Susceptibility to SARS-CoV-2 corresponds to the amino acid sequence conservation of the RBM in ACE2, the team conducted an in silico analysis of the available ACE2 protein sequences.

This revealed that, compared with humans, the RBM regions that interact with the receptor-RBD of SARS-CoV-2 are well conserved in both the rhesus macaque and the cat, whereas they were more diverse in other species.

SARS-CoV-2 had not needed to adapt in order to infect the animals

Studies have previously demonstrated that SARS-CoV-2 can undergo rapid genetic changes in vitro.

Given the observed viral replication in the rhesus macaque and cat AEC cultures, the researchers performed whole-genome sequencing to assess whether any mutations suggestive of viral adaptation had occurred.

Neither the viral inoculum nor the progeny virus showed any obvious signs of the nucleotide transitions that lead to nonsynonymous mutations, irrespective of the animal species.

“Whole-genome sequencing indicated that the current circulating SARS-CoV-2 D614G-variant can efficiently infect rhesus macaque and cat airway epithelial cells,” writes the team.

The researchers recommend close surveillance of the rhesus macaque and cat

The team says that these findings, together with previously documented spillover events, suggest that close surveillance of these animals, including closely-related species in the wild, in captivity and in household settings is warranted.

“Taken together, our results highlight that in vitro well-differentiated airway epithelial models in combination with high throughput genomic analysis can be applied as viable surrogate models to refine, reduce, and replace animal experimentation to evaluate host tropism of respiratory viruses, and thereby providing important insight into the host spectrum of SARS-CoV-2,” concludes the team.

*Important Notice

bioRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.
Posts: 2723
Joined: Fri Jun 26, 2020 5:22 am

Re: Airborne Dust / Zoonosis / Land Use

Post by trader32176 »

Researchers assess risks posed by SARS-CoV-2 to Antarctica wildlife

11/12/20 ... dlife.aspx

An international team of researchers from Spain, the United States, Brazil, Argentina, France, Australia and Chile has assessed risks posed by the ongoing coronavirus disease 2019 (COVID-19) pandemic on Antarctica wildlife. Their study has now been published in the latest issue of the journal Science of the Total Environment.


The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes COVID-19 has led to the infection of over 52.1 million people worldwide. In light of resurgent cases, many countries have attempted to stop the spread of this highly infectious virus by breaking the transmission chain with restrictive measures and second lockdowns – as in the case of Belgium, Italy and the United Kingdom. The virus and its knock-on effects have taken a severe toll on global public health and the economy.

Many believe the virus to have a zoonotic origin, meaning it originated among animals and has since jumped to humans. This also suggests a cross-species transmission of the infection among animals. “All members of the seven identified coronaviruses that infect humans are suspected of having zoonotic origins,” say the researchers. There has also been evidence of “reverse zoonosis” wherein the infection is transmitted from humans to animals.


Before March 2020, Antarctica was the only continent untouched by SARS-CoV-2. However, there are now concerns about the virus’ potential to spread throughout the region, after at least one COVID-19 positive person was found to have visited several sites along the Antarctic Peninsula during the region’s tourist season in March. The researchers suggest that the potential for humans to transmit the virus to wildlife in Antarctica remains a threat. Thus, they have proposed a series of measures that they believe would limit the transmission of SARS-CoV-2 to Antarctic wildlife.

Cross-species transmission

Several factors determine the potential of SARS-CoV-2 to show cross-species transmission. Among other coronaviruses, evidence suggests that their spread first occurs among animals who often act as reservoirs of this type of infection that then go on spread it to humans. SARS-CoV-2 itself has been found among bats and pangolins and a wide range of vertebrate hosts, including minks, domestic cats and dogs, ferrets and hamsters, among others.

Host susceptibility to the virus is determined by the presence of the angiotensin-converting enzyme 2 (ACE2) cell surface receptor, predicted by an in-silico analysis. This analysis shows a low risk of this infection among fish, amphibian, reptile and bird species.

Risk among Antarctic personnel

Until October 2020, there had been no human cases in the Antarctic research station among the nearly 5,000 personnel. Since most of the research work and tourism often take place within close confines, there is a high risk of human to human transmission, wrote the researchers. Early detection and segregation is thus vital, they wrote.

Stability of the virus in the Antarctic environment and transmission risk to wildlife

SARS-CoV-2 is relatively stable in the form of aerosols and can survive on surfaces for up to 72 hours, but temperature and humidity are important for its viability as well as infectivity. SARS-CoV-2’s stability is increased in cold conditions, the team explains. The Antarctic’s environment thus could be very hospitable to the virus and could help facilitate its transmission.

The researchers suggest that the risk of virus introduction and transmission is particularly heightened in areas with higher research work and tourist activities, such as the South Shetland Islands, the northern Antarctic Peninsula and Victoria Land.

The team also says that there has been evidence of viral shedding in the feces of infected persons in the region, which increases the risk of wastewater contamination. This presents a possible source of infection for wildlife and could lead to reverse zoonosis

Susceptibility of Antarctic wildlife to infection by SARS-CoV-2

The researchers write that the Adélie penguin (Pygoscelis adeliae) and the emperor penguin (Aptenodytes forsteri) have a very low risk of SARS CoV-2 infection, similar to that of other birds. Antarctic pinnipeds also have a low risk of the infection.

There are 14 cetacean species, of which 12 species, including Antarctic minke whale (Balaenoptera bonaerensis), killer whale (Orcinus orca) and sperm whale (Physeter macrocephalus), carry a medium to a moderately higher risk of transmission.

Future studies can actually quantify the risk of infection among Antarctic wildlife. Moreover, there is currently a gap in our knowledge regarding the susceptibility of Antarctic wildlife to SARS-CoV-2. In-silico modeling could help us to understand which animals are susceptible to this infection.

Preventative measures for researchers and tourists reduce viral spread

The researchers recommend a range of measures that could help prevent SARS-CoV-2’s spread among Antarctic wildlife, with a focus on research and tourist activities on the continent:

For the research facilities staff (crew, scientific and technical personnel):

Getting tested for SARS-CoV-2 before entering Antarctica and following quarantine procedures for two weeks.
Self-isolation for those with symptoms should, including no contact with humans or animals.
Practicing caution while handling animals.
Disinfecting clothing prior to and after working with animals.
Disinfecting field equipment.
Preventing inadvertent exposure of wild animals to unattended field equipment.
Maintaining personal hygiene.
Limiting movements, unless absolutely essential.

For tourists (including visiting research staff):

Getting tested for SARS-CoV-2 before entering Antarctica and following quarantine procedures for two weeks.
Self-isolation for those with symptoms should, including no contact with humans or animals.
Those in contact with an infected person in a vessel need to self-isolate and must be prevented from coming in contact with wildlife.
Maintaining a minimum distance of 5 m or greater from wildlife.
Preventing exposure to wildlife and field equipment.
Not to sit or lie on bare ground or rocks.
Maintaining personal hygiene.

Additional recommendations:

Surveilling wastewater from cruise ships, research stations and research vessels for the presence of SARS-CoV-2
Posts: 2723
Joined: Fri Jun 26, 2020 5:22 am

Re: Airborne Dust / Zoonosis / Land Use

Post by trader32176 »

Mink farms potential viral reservoirs for SARS-CoV-2

11/12/20 ... CoV-2.aspx

With no end to the coronavirus disease 2019 (COVID-19) pandemic in sight, potential new reservoirs of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in animal populations are closely watched. A new study published in the journal Science in November 2020 describes the probable transmission of the virus between farmed minks and humans working on the mink farm, even with biosecurity measures in place and the culling of infected farms as soon as an infection is reported.

Zoonotic virus infects many animal species

The COVID-19 pandemic has been strongly suspected to be zoonotic from the start
when the Wuhan sea fish and wild animal meat market was thought to be the source. However, many cases were later traced back to before the earliest market-linked case, suggesting other sources could be possible. In short, the intermediate animal host of SARS-CoV-2 is yet to be identified.

The virus in question has been shown to successfully infect dogs, cats, ferrets, hamsters, and many non-human primates, but not pigs and several kinds of poultry. The natural infection has been detected in some pet dogs and cats and zoo-kept tigers and lions. More recently, cases have also been reported in large numbers in farmed mink.

Separate infections on each farm

The current study used whole-genome sequencing to analyze the patterns of infection on mink farms in the Netherlands, using genetic sequencing data along with epidemiological and surveillance data. Early on, only two Dutch mink farms were implicated in April 2020. This was followed by an examination of all the mink farms in the country to identify the routes of transmission.

The study focuses on the results from the first 16 farms where mink were found to be infected. This included around 100 people, half had a positive RT-PCR test, and half had a positive serological test. About 70% of the people tested were positive overall.

From the first two farms found to be infected, one had no cases, and one had a single hospitalized employee before the first interview, but all the employees on the second farm had antibodies to the virus. The viral sequences obtained from the two farms were distinct, showing that each farm had been infected separately.

Sequence clusters in same-farm humans and minks

With the next farm, the employees first tested negative for the virus but later developed symptoms. Several then tested positive. In all these farms, the same sequences were obtained from infected humans and mink at each farm.

There were five different clusters from 16 mink farms, but the clusters did not appear to follow any geographic pattern, even though many farms within a cluster had the same owner. Of the 18 sequences from the mink farmworkers or their close contacts, from 7 farms, the human and mink sequences were almost identical. However, in two farms, the human and mink sequences were different. In two farms, the mink sequences from one clustered with the human sequences from another because of the staff's movement between the two farms.

The sequence clusters found on these farms differed from those found in COVID-19 cases in the neighboring area. This rules out community-acquired infection. The infection also did not appear to have come from Poland, a possibility with the Polish origin of many seasonal migrants.

Rapid viral evolution

A peculiarity of the mink infections was the rapid evolution of the virus in these animals, with up to 12 single nucleotide polymorphisms and deletions of up to 9 nucleotides being observed within one farm's sequences. None of these mutations were unique, being found in humans as well.

Almost 70% of the farmworkers and their close contacts were infected, which shows that the presence of mink infection is a risk factor for COVID-19. Again, C>U substitutions for U>C substitutions were noted recently to be eight times higher. Such substitutions are a marker of host adaptation. This marker was present, though at a lower level, and 3.5 times higher in mink sequences.

The estimated annual substitution rate per site is around 1.16*10^-3 for this virus, or around a mutation a week. This accounts for the high diversity in sequences and suggests the virus had been circulating in mink farms for weeks prior to detecting the first case.

The mutation rate seems to be relatively rapid since even when the PCR came up negative one week before the first positive case, the sequences isolated from that farm continued to show relative diversity. One reason could be the high mink density, which favors viral spread and exposure to high doses of the virus.

Implications for public health

The outbreak on these farms appears to have originated in animals since the human and animal sequences from the farms show phylogenetic separation from the community-derived sequences. However, these infections did not appear to cause community outbreaks.

The study could not identify how the infection spread from farm to farm, but the authors suggest that temporary workers, who were not tested, might have been involved. They caution, "SARS-CoV-2 infections have also been described in mink farms elsewhere. It is imperative that fur production and the trading sector should not become a reservoir for future spillover of SARS-CoV-2 to humans."
Posts: 2723
Joined: Fri Jun 26, 2020 5:22 am

Re: Airborne Dust / Zoonosis / Land Use

Post by trader32176 »

Domestic cats can be asymptomatic carriers of SARS-CoV-2, show studies

11/19/20 ... udies.aspx

Two recently published studies from Kansas State University researchers and collaborators have led to two important findings related to the COVID-19 pandemic: Domestic cats can be asymptomatic carriers of SARS-CoV-2, but pigs are unlikely to be significant carriers of the virus. SARS-CoV-2 is the coronavirus responsible for COVID-19.

" Other research has shown that COVID-19-infected human patients are transmitting SARS-CoV-2 to cats; this includes domestic cats and even large cats, such as lions and tigers. Our findings are important because of the close association between humans and companion animals."

- Jürgen A. Richt, Regents Distinguished Professor, Kansas State University, College of Veterinary Medicine

There are about 95 million house cats in the U.S. and about 60 million to 100 million feral cats, Richt said.

Richt is the senior author on the two recent collaborative publications in the journal Emerging Microbes & Infections: "SARS-CoV-2 infection, disease and transmission in domestic cats" and "Susceptibility of swine cells and domestic pigs to SARS-CoV-2."

Through their in-depth study at the K-State Biosecurity Research Institute, or BRI, at Pat Roberts Hall, the researchers studied susceptibility to infection, disease and transmission in domestic cats.

They found that domestic cats may not have obvious clinical signs of SARS-CoV-2, but they still shed the virus through their nasal, oral and rectal cavities and can spread it efficiently to other cats within two days. Further research is needed to study whether domestic cats can spread the virus to other animals and humans.

"This efficient transmission between domestic cats indicates a significant animal and public health need to investigate a potential human-cat-human transmission chain," said Richt, who is also the director of the university's Center of Excellence for Emerging and Zoonotic Animal Diseases, known as CEEZAD, and the Center on Emerging and Zoonotic Infectious Diseases, known as CEZID.

For the study involving pigs, the researchers found that SARS-CoV-2-infected pigs are not susceptible to SARS-CoV-2 infection and do not appear to transmit the virus to contact animals.

"Pigs play an important role in U.S. agriculture, which made it important to determine the potential SARS-CoV-2 susceptibility in pigs," Richt said. "Our results show that pigs are unlikely to be significant carriers of SARS-CoV-2."

The BRI has provided the high-security laboratories for Richt and collaborators to study SARS-CoV-2. It is a biosafety level-3 and biosafety level-3 agriculture facility that houses important multidisciplinary research, training and educational programs on pathogens that affect animals, plants and insects, as well as food safety and security.

Richt and his collaborators plan further studies to understand SARS-CoV-2 transmission in cats and pigs. They also plan to study whether cats are immune to SARS-CoV-2 reinfection after they have recovered from a primary SARS-CoV-2 infection.

"This research is important for risk assessment, implementing mitigation strategies, addressing animal welfare issues, and to develop preclinical animal models for evaluating drug and vaccine candidates for COVID-19," Richt said.
Posts: 2723
Joined: Fri Jun 26, 2020 5:22 am

Re: Airborne Dust / Zoonosis / Land Use

Post by trader32176 »

Genetic variations of SARS-CoV-2 transmission in cats

11/19/20 ... -cats.aspx

Using cats as an animal model to study severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission, researchers have determined the virus has a narrow transmission bottleneck.

The current coronavirus disease 2019 (COVID-19) pandemic, caused by the SARS-CoV-2 agent, is widely believed to be of zoonotic origin (meaning it had originated in animals and has since jumped to human hosts). Much scientific research has subsequently been directed toward understanding the genetic diversity of RNA viruses, like SARS-CoV-2.

An animal model is useful for studying viral genetic variation in the host and between different hosts. SARS-CoV-2 animal models have included Syrian hamsters, ferrets, cats, and dogs, among which natural transmission has been seen only in mink, cats, and ferrets. Only in cats, however, has SARS-CoV-2 been detected in the lower respiratory tract; infection in this region for humans has been linked to severe cases of COVID-19.

Transmission bottleneck

The term transmission bottleneck refers to a significant reduction in virus population during transmission. Observing the development of transmission bottlenecks is important for understanding the evolution of respiratory viruses. Narrow transmission bottlenecks, where there is weak natural selection, could reduce adaptations in the seasonal flu virus and could also play a role in SARS-CoV-2 transmission. Accurate knowledge of the size of the SARS-CoV-2 transmission bottleneck could thus help forecast its evolution.

Since previous studies in humans on the transmission bottleneck have reported conflicting results, a new study has utilized a cat model. The study's findings are available on bioRxiv*, the preprint server

SARS-CoV-2 genetic diversity in cats

The researchers, from the University of Wisconsin-Madison and Emory University in the USA, used genome sequencing of the virus in index cats, cats first infected with the virus and in other cats that the index cats transmitted the virus to. They then studied changes in these sequences over time to determine genetic variation.

They inoculated three domestic cats with a SARS-CoV-2 human isolate from Tokyo. Each inoculated cat was then kept with a virus-free cat, starting a day after the inoculation. They then collected nasal swabs daily for up to 10 days.

They found 86% of the variants were found in a single cat, 8% in 2 to 5 cats, and the remaining variants were found in all six cats. Around 43% of the mutations occurred at a frequency of 3 to 10%, and about 8% occurred at a frequency of 40-50%, with the frequency of variations remaining about the same over time in the index cats.

Purifying selection is when harmful mutations are removed and result in more low-frequency variants. Positive selection results in more high-frequency variations and is when useful variants are retained in the population. Since about half of the variants occur at low frequency, purifying selection is predominant in cats. By comparing nonsynonymous and synonymous nucleotide diversity, the authors found that genetic variations in the index cats were driven by genetic drift, or mutations that occurred by random chance.

To determine the transmission bottleneck size in cats, the authors studied how much genetic diversity was lost after transmission. They found a lower number of variants in the contact cats compared to its index cat. Furthermore, they found the effective bottleneck size to be five (after two and three days, index and contact cat, respectively); three (after five and six days); and two (after four and five days). This is similar to other studies on flu virus transmission in humans.

SARS-CoV-2 mutation rate in cats is slow

Although genetic variation within hosts was low, there were two notable mutations. One, the S H655Y, variant has been seen before and is related to the spike protein glycoprotein fusion. The other variant, E S67S, has not been seen before. Both variants were transmitted in two of the three cats.

The results suggest that genetic selection within hosts is weak and the transmission bottleneck is narrow, even during close contact, indicating that SARS-CoV-2 is perhaps already well adapted to mammalian hosts.

"The strong role of genetic drift may combine with the relatively slow mutation rate and narrow transmission bottlenecks to slow the overall pace of viral evolution," write the authors.

The narrow transmission bottleneck finding conflicts with some human studies. However, the authors suggest that the current study's experimental design avoids challenges faced in previous human studies; namely, the potential for other sources of exposure to infection, and not only intra-household transmission.

There have been reports of natural transmission from humans to cats, so cats could be a feasible model for studying virus genetic diversity. The narrow transmission bottleneck suggests that SARS-CoV-2 variations that could affect innate immunity or antivirals could be slow.

However, variants do arise early and are capable of being transmitted in cats, a potential reservoir species, and host-specific adaptations are also inevitable in SARS-CoV-2. This may also affect humans if exposed to species-specific adaptations, requiring continued studies on sequencing and understanding SARS-CoV-2 genetic diversity in different hosts.
Posts: 2723
Joined: Fri Jun 26, 2020 5:22 am

Re: Airborne Dust / Zoonosis / Land Use

Post by trader32176 »

Change in attitude towards wildlife consumption in China: Survey

11/22/20 ... urvey.aspx

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes COVID-19 disease first emerged at the end of 2019 in Wuhan, Hubei, China. Early cases of the infection were seen among those in contact with an animal market.

Researchers Shuchang Liu, from the School of Biosciences, University of Nottingham, UK, along with Zheng Feei Ma, Department of Health and Environmental Sciences, Xi’an Jiaotong-Liverpool University, Suzhou, China, Yutong Zhang and Yingfei Zhang from Jinzhou Medical University, China wanted to explore the current attitudes towards consuming exotic animals several months after the outbreak. Their study titled, “Attitudes towards Wildlife Consumption inside and outside Hubei Province, China, concerning the SARS and COVID-19 Outbreaks,” is published in the latest issue of the journal Human Ecology.

SARS and animals

In November 2002, there was an outbreak of the severe acute respiratory syndrome (SARS) virus infection in the Foshan municipality, Guangdong Province. The peak of the outbreak was seen in February 2003. SARS has been known to affect those who lived near animal markets and infected those who handled animals or were food practitioners.

The coronavirus disease 2019 (COVID-19) outbreak in December 2019 was traced back to the Huanan seafood market. Early cases were those who had visited the local fish and wildlife market before the outbreak. They had been exposed to wildlife such as “poultry, bats, marmots, hedgehogs, badgers, birds, and snakes,” wrote the researchers. Intermediate animal hosts were speculated to be bats or pangolins.

This study was conducted to see if there has been any change post-COVID in the attitude towards eating wildlife after the outbreaks.

Study design

This was a cross-sectional study conducted between 7 April 2020 and 20 April 2020. All adult non-pregnant individuals who were currently living either in or outside Hubei Province, China, willing to participate in the study, were included in the study.

A 20 question questionnaire was given to the participants. These had:

11 questions on basic socioeconomic information including gender, age, level of education, occupation, marital status, religion, and residential city
Participants were asked if they were healthcare providers
They were asked if they or their friends/relatives were currently diagnosed with COVID-19
5 questions were dedicated to SARS and COVID-19.
Participants were asked their possible course of action if they saw someone hunting illegally.
They were asked if they had ever eaten wildlife such as “palm civets, snakes, wild boar, frogs, monkeys, bats, or pangolins” during each of the outbreaks. Their reason for eating or not eating wildlife was also asked (taste, nutrition, novelty, social status, etc. for eating and dislike, law, wildlife protection, etc. for not eating)
Participants were asked if their opinions regarding eating wildlife changed after the SARS outbreak
Questions regarding if the participants considered palm civets to be carriers of SARS, and bats to be carriers of SARS-CoV-2 was also asked.

The questionnaire was distributed via WeChat, QQ, and Baidu Post Bar.


The study results were as follows:

In the survey, a total of 348 adults took part, of which 177 were males
The average age of the participants was 29.4 years. Over 95 percent were less than 50 years of age.
Two-thirds of the participants resided in Hubei
None of the study participants was currently diagnosed with COVID-19, and only two participants indicated that they had friends who had been diagnosed with COVID-19.
During the SARS outbreak, the percentage of people consuming wildlife was 27 percent
During the COVID-19 pandemic, the percentage of participants consuming wildlife was 17.8 percent
The most typical reasons provided by participants for eating wildlife was the novelty of the meat (among 64.9 percent during the SARS outbreak and 54.8 percent during the COVId-19 outbreak).
The commonest reasons for never having eaten wild animal meat was dislike for the meat (47.7 percent during SARS and 39.9 percent during COVID-19)
52.5 percent reported that they had stopped eating wild animal meat because the law protected these species.
The team found that educational level was significantly associated with wildlife consumption during the SARS and COVID-19 outbreaks.
More than half of the participants thought that palm civets were carriers of SARS (53.7 percent), and 42.2 percent thought bats were carriers of SARS-CoV-2.
In response to the question asking what they would do if they saw somebody hunting illegally, the response was as follows:
26.7 percent would definitely stop it
64.4 percent would try to stop it
8.9 percent would ignore it


The authors of the study conclude that their findings indicate that over a period of 17 years between the SARS outbreak and the COVID-19 outbreak, attitudes towards the consumption of wildlife in China changed for the better and changed significantly. They write, “At present, Chinese populations seem to be in favor of stopping wildlife consumption and fighting against illegal hunting. However, some people in China will likely continue to consume wildlife meat for many reasons, including believed health benefits.”
Posts: 2723
Joined: Fri Jun 26, 2020 5:22 am

Re: Airborne Dust / Zoonosis / Land Use

Post by trader32176 »

Research reveals areas where the next pandemic could emerge

11/24/20 ... merge.aspx

Key findings

Almost half the world's most connected cities straddle animal-human spillover hotspots
14-20 percent of these cities are in areas with poor health infrastructure, meaning infections resulting from spillovers are likely to go unreported
South and southeast Asia and Sub-Saharan Africa have the most cities at greatest risk
The new methodology builds on understanding sources of pathogen transmission at wildlife-human interfaces by locating the most connected airports adjacent to these interfaces, where infections can spread quickly globally.

An international team of researchers has taken a holistic approach to reveal for the first time where wildlife-human interfaces intersect with areas of poor human health outcomes and highly globalized cities, which could give rise to the next pandemic unless preventative measures are taken.

Areas exhibiting a high degree of human pressure on wildlife also had more than 40 percent of the world's most connected cities in or adjacent to areas of likely spillover, and 14-20 percent of the world's most connected cities at risk of such spillovers likely to go undetected because of poor health infrastructure (predominantly in South and South East Asia and Sub-Saharan Africa). As with COVID-19, the impact of such spillovers could be global.

Led by the University of Sydney and with academics spanning the United Kingdom, India and Ethiopia, the open-access paper shows the cities worldwide that are at risk. Last month, an IPBES report highlighted the role biodiversity destruction plays in pandemics and provided recommendations. This Sydney-led research pinpoints the geographical areas that require greatest attention.

The paper, "Whence the next pandemic? The intersecting global geography of the animal-human interface, poor health systems and air transit centrality reveals conduits for high-impact spillover", has published in the leading Elsevier journal, One Health. City lists for yellow, orange and red alert zones are available in open access.

Lead author Dr Michael Walsh, who co-leads the One Health Node at Sydney's Marie Bashir Institute for Infectious Diseases and Biosecurity, said that previously, much has been done to identify human-animal-environmental hotspots.

" Our new research integrates the wildlife-human interface with human health systems and globalization to show where spillovers might go unidentified and lead to dissemination worldwide and new pandemics."

- Dr. Michael Walsh, University of Sydney's School of Public Health, Faculty of Medicine and Health

Dr Walsh said that although low- and middle-income countries had the most cities in zones classified at highest risk for spillover and subsequent onward global dissemination, it should be noted that the high risk in these areas was very much a consequence of diminished health systems. Moreover, while not as extensively represented in the zone of highest risk because of better health infrastructure, high-income countries still had many cities represented in the next two tiers of risk because of the extreme pressures the affluent countries exert on wildlife via unsustainable development.

Identifying areas at risk

The researchers took a three-staged approach:

1.First, identify where the sharing of space between wildlife and humans is greatest, and therefore where spillover events would be expected to be most common. The researchers refer to this as the 'yellow' and 'orange' alert zones of two- and three-way interactions between humans, domesticated animals and wildlife.

2.Next, identify where areas of high wildlife-human interface coincide with areas of poor health system performance, which would comprise areas expected to miss ongoing chains of transmission following a spillover event;

3.Finally, identify cities within or adjacent to these areas of spillover risk that are highly connected to the network of global air travel, and therefore may serve as conduits for future pandemics (city names in the alert zones can be seen by zooming up on the high-resolution maps).

"This is the first time this three-staged geography has been identified and mapped, and we want this to be able to inform the development of multi-tiered surveillance of infections in humans and animals to help prevent the next pandemic," the paper reads.

Of those cities that were in the top quartile of network centrality, approximately 43 percent were found to be within 50km of the spillover zones and therefore warrant attention (both yellow and orange alert zones). A lesser but still significant proportion of these cities were within 50km of the red alert zone at 14.2 percent (for spillover associated with mammal wildlife) and 19.6 percent (wild bird-associated spillover).

Dr Walsh said although it would be a big job to improve habitat conservation and health systems, as well as surveillance at airports as a last line of defense, the benefit in terms of safeguarding against debilitating pandemics would outweigh the costs.

"Locally-directed efforts can apply these results to identify vulnerable points. With this new information, people can develop systems that incorporate human health infrastructure, animal husbandry, wildlife habitat conservation, and movement through transportation hubs to prevent the next pandemic," Dr. Walsh said.

"Given the overwhelming risk absorbed by so many of the world's communities and the concurrent high-risk exposure of so many of our most connected cities, this is something that requires our collective prompt attention."
Post Reply