New findings on the origin of COVID-19, this animal is highly suspected of transmitting the virus to humans

Jakarta –

Genetic analysis of hundreds of swabs taken at the location where the COVID-19 outbreak first spread is revealing. Researchers previously collected several samples from the walls, floors, machinery and waterways of a seafood wholesale market in Huanan, Wuhan, China.

Scientists now say they know exactly which animal species are where COVID-19 spreads.

The species in the area where the SARS-COV-2 virus was found include raccoon dogs, hoary bamboo rats, dogs, European rabbits, Amur porcupines, Malayan porcupines, Reeves muntjacs, Himalayan marmots and palmets.

The new findings add to strong evidence, but do not directly indicate that SARS-CoV-2 jumped from infected animals to humans.

The researchers identified animal species on the market through a technique known as metagenomic sequencing. It reads all the genetic material present in a sample and then screens it to understand where it came from.

The analysis, published Thursday in the journal Cell, does not prove that the animals were infected with the virus, but their DNA was found in close proximity to the virus, sometimes on the same swabs. That means there is a strong possibility that there will be infected animals at the market.

Of the animals on the market, rabbits, dogs and raccoon dogs are known to be susceptible to the Covid-19 disease. Raccoon dogs have also been shown to spread disease, making them a strong candidate as the animals that first transmitted the virus to humans.

Age of viruses

The international research team behind the study also used genetic material from samples found in the market to carry out evolutionary analysis, a technique that helps them estimate when the virus appeared first and what are the closest genetic relationships.

“This is essentially a carbon date virus,” said senior study author Dr. Kristian Andersen, director of infectious disease genomics at the Scripps Institute for Translational Research in La Jolla, California. .

By understanding how quickly the virus that causes covid changes or moves, he received about two genetic mutations per month, which made it possible to find out the approximate life of the virus.

Researchers believe that the virus that triggered the pandemic emerged sometime between mid-November and mid-December 2019.

Their study shows that the SARS-COV-2 virus that was present on the market appeared at the same time as viruses from the largest pandemic, suggesting that the two are the same.

If it first came from somewhere else and then traveled to a market where its spread increased – as suggested by the COVID-19 lab leak theory, the timing of the discovery of the virus would have been different market since the crisis. of the virus that caused the pandemic, Andersen said.

Other lines of evidence point in the same direction.

Nearly a third of the first 174 people with COVID-19 had a history of travel to markets, and many other residents lived near markets, within the city of 12 million people.

(naf/kna)