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The global Covid-19 pandemic may have been sparked by stray dogs eating bat meat, a study has found.
After analysing coronavirus across different species, a top biology researcher in Canada concluded that feral dogs may have helped transmit the new Sars-CoV-2 disease – which causes Covid-19 – into humans.
The ancestor of the virus and its nearest relative, a bat coronavirus, could have infected the intestines of canines where it evolved before jumping to humans, Professor Xuhua Xia’s study suggests.
The findings of Prof Xia, from the University of Ottawa’s biology department, are published online in the advanced access edition of the journal Molecular Biology and Evolution.
The World on Coronavirus lockdown
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View of the illuminated statue of Christ the Redeemer that reads “Thank you” as Archbishop of the city of Rio de Janeiro Dom Orani Tempesta performs a mass in honor of Act of Consecration of Brazil and tribute to medical workers amidst the Coronavirus (COVID – 19) pandemic
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A UK government public health campaign is displayed in Piccadilly Circus
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Bondi Beach, Australia
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A usually busy 42nd Street is seen nearly empty in New York
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Rome
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An Indian man paddles his bicycle in front of a mural depicting the globe covered in a mask, as India remains under an unprecedented lockdown over the highly contagious coronavirus
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Military vehicles cross Westminster Bridge after members of the 101 Logistic Brigade delivered a consignment of medical masks to St Thomas’ hospital
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Aerial view of the empty 9 de Julio avenue in Buenos Aires in Argentina
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A view of an empty Grand Canal
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Las Ramblas, Barcelona, Spain
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Aerial view of the empty Central cemetery in Bogota, Columbia
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Miami, Florida
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The facade of the Palacio de Lopez (seat of the government palace)
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Aerial view of the empty Simon Bolivar park in Bogota,
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An LAPD patrol car drives through Venice Beach Boardwalk
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Venice Beach, California
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Los Angeles, California
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Surfers Paradise is seen empty in Australia
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Many shops stand shuttered on the Venice Beach boardwalk
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Empty escalators are seen at a deserted train station during morning rush hour after New South Wales began shutting down non-essential businesses
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A nearly empty Times Square in New York
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Caracas
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Metropolitan Cathedral of San Salvador
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A general view of an unusually quiet Midland Park in Wellington, New Zealand
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A general view of an unusually quiet Civic Square at lunchtimein Wellington, New Zealand
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A policeman rides his motorcycle wearing a face mask in front of a closed shopping mall in Buenos Aires, Argentina
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Florida Keys
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The historic Channel 2 Bridge closed to fishermen, bikers and pedestrians in Florida Keys
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The Beach on Scenic Gulf Drive near Seascape Resort in south Walton County, Florida sits empty of tourists
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Surfers Paradise is seen empty in Australia
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A deserted Rajpath leading to India Gate in New Delhi
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A general view is seen of a closed Luna Park in Sydney, Australia
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A general view is seen of a closed Luna Park in Sydney, Australia
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Empty roads are pictured following the lockdown by the government amid concerns about the spread of coronavirus disease (COVID-19) outbreak, in Kathmandu, Nepal
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An empty New York Subway car i
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The empty pedestrian zone is seen in the city of Cologne, western Germany,
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Place de la Comedie in the city of Montpellier , southern France
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An empty street in Kuwait city
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A building is covered by the Portuguese message: “Coronavirus: take precaution” over empty streets in downtown Sao Paulo, Brazil,
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A general view shows an empty street after a curfew was imposed to prevent the spread of the coronavirus disease (COVID-19), in Riyadh, Saudi Arabia
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Parliament of Canada is pictured with empty street during morning rush hour
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A near empty beach on Southend seafront in England
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Near empty Keswick town centre in Cumbria, England
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View of the illuminated statue of Christ the Redeemer that reads “Thank you” as Archbishop of the city of Rio de Janeiro Dom Orani Tempesta performs a mass in honor of Act of Consecration of Brazil and tribute to medical workers amidst the Coronavirus (COVID – 19) pandemic
Getty Images
2/43
A UK government public health campaign is displayed in Piccadilly Circus
Reuters
3/43
Bondi Beach, Australia
Getty Images
4/43
A usually busy 42nd Street is seen nearly empty in New York
AFP via Getty Images
5/43
Rome
AFP via Getty Images
6/43
An Indian man paddles his bicycle in front of a mural depicting the globe covered in a mask, as India remains under an unprecedented lockdown over the highly contagious coronavirus
Getty Images
7/43
Military vehicles cross Westminster Bridge after members of the 101 Logistic Brigade delivered a consignment of medical masks to St Thomas’ hospital
Getty Images
8/43
Aerial view of the empty 9 de Julio avenue in Buenos Aires in Argentina
AFP via Getty Images
9/43
A view of an empty Grand Canal
Reuters
10/43
Las Ramblas, Barcelona, Spain
Getty Images
11/43
Aerial view of the empty Central cemetery in Bogota, Columbia
AFP via Getty Images
12/43
Miami, Florida
AFP via Getty Images
13/43
The facade of the Palacio de Lopez (seat of the government palace)
AFP via Getty Images
14/43
Aerial view of the empty Simon Bolivar park in Bogota,
AFP via Getty Images
15/43
An LAPD patrol car drives through Venice Beach Boardwalk
AP
16/43
Venice Beach, California
Getty Images
17/43
Los Angeles, California
Getty Images
18/43
Surfers Paradise is seen empty in Australia
Getty Images
19/43
Many shops stand shuttered on the Venice Beach boardwalk
Getty Images
20/43
Empty escalators are seen at a deserted train station during morning rush hour after New South Wales began shutting down non-essential businesses
REUTERS
21/43
A nearly empty Times Square in New York
AFP via Getty Images
22/43
Caracas
AFP via Getty Images
23/43
Metropolitan Cathedral of San Salvador
AFP via Getty Images
24/43
A general view of an unusually quiet Midland Park in Wellington, New Zealand
Getty Images
25/43
A general view of an unusually quiet Civic Square at lunchtimein Wellington, New Zealand
Getty Images
26/43
A policeman rides his motorcycle wearing a face mask in front of a closed shopping mall in Buenos Aires, Argentina
AFP via Getty Images
27/43
Florida Keys
AP
28/43
The historic Channel 2 Bridge closed to fishermen, bikers and pedestrians in Florida Keys
AP
29/43
The Beach on Scenic Gulf Drive near Seascape Resort in south Walton County, Florida sits empty of tourists
AP
30/43
Surfers Paradise is seen empty in Australia
Getty Images
31/43
A deserted Rajpath leading to India Gate in New Delhi
AFP via Getty Images
32/43
A general view is seen of a closed Luna Park in Sydney, Australia
Getty Images
33/43
A general view is seen of a closed Luna Park in Sydney, Australia
Getty Images
34/43
Empty roads are pictured following the lockdown by the government amid concerns about the spread of coronavirus disease (COVID-19) outbreak, in Kathmandu, Nepal
Reuters
35/43
An empty New York Subway car i
AFP via Getty Images
36/43
The empty pedestrian zone is seen in the city of Cologne, western Germany,
AFP via Getty Images
37/43
Place de la Comedie in the city of Montpellier , southern France
AFP via Getty Images
38/43
An empty street in Kuwait city
AFP via Getty Images
39/43
A building is covered by the Portuguese message: “Coronavirus: take precaution” over empty streets in downtown Sao Paulo, Brazil,
AP
40/43
A general view shows an empty street after a curfew was imposed to prevent the spread of the coronavirus disease (COVID-19), in Riyadh, Saudi Arabia
Reuters
41/43
Parliament of Canada is pictured with empty street during morning rush hour
AFP via Getty Images
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A near empty beach on Southend seafront in England
PA
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Near empty Keswick town centre in Cumbria, England
PA
In his study, Prof Xia analysed 1,252 full-length betacoronavirus genomes shared via an open access database.
He said that Sars-CoV-2 and its closest known relative, the bat coronavirus BatCoV RaTG13, which shares 96 per cent sequence similarity, have the lowest amount of a particular region of DNA which help the immune system tackle disease.
Only genomes from canine coronaviruses, which have already caused a highly contagious intestinal disease worldwide in dogs, have similar genomic values, the study found.
Dogs also have coronaviruses which affect their respiratory systems as well as their digestive systems, the paper notes.
Prof Xia wrote that the suggested link between canines and humans is “further corroborated by a recent report that a high proportion of Covid-19 patients also suffer from digestive discomfort.”
“In fact, 48.5 per cent presented with digestive symptoms as their chief complaint,” he states in the report.
“These observations are consistent with the hypothesis that Sars-CoV-2 has evolved in mammalian intestine or tissues associated with the intestine.”
However, the paper was criticised by professor James Wood, head of the department of Veterinary Medicine and researcher in infection dynamics at the University of Cambridge.
He said: “I find it difficult to understand how the author has been able to conclude anything from this study, or to hypothesise much, let alone that the virus causing Covid-19 may have evolved through dogs.
“There is far too much inference and far too little direct data. I do not see anything in this paper to support this supposition and am concerned that this paper has been published in this journal.
“I do not believe that any dog owners should be concerned as a result of this work.”
Prof Xia said: “Our observations have allowed the formation of a new hypothesis for the origin and initial transmission of Sars-CoV-2.
“The ancestor of Sars-CoV-2 and its nearest relative, a bat coronavirus, infected the intestine of canids, most likely resulting in a rapid evolution of the virus in canids and its jump into humans.
“This suggests the importance of monitoring Sars-like coronaviruses in feral dogs in the fight against Sars-CoV-2.”
Nearly two million people have contracted Sars-CoV-2 since it first appeared at a seafood market in Wuhan, China, in late 2019, according to a global tracker by Johns Hopkins University.
More than 120,000 people have so far died after developing Covid-19.
Source: Evening Standard UK
