Tue. Sep 27th, 2022

Sars-Cov-19: are snakes the cause of the epidemic?

A track to be taken seriously!

As China steps up health measures to limit the spread of 2019-nCoV, which has already killed 17 people, scientists seem to have pinpointed the animal reservoir for this new coronavirus.

The epidemic of pneumonia caused by a new coronavirus in China continues to expand. On January 23, there were 555 confirmed cases, mainly in the province of Hubei where Wuhan is located, and 17 people who died. The epidemic is concentrated in eastern China and the surrounding countries although a first case has been identified in Seattle in the United States.

The Chinese government has instituted drastic measures to contain the spread of 2019-nCoV. Wuhan airports and train stations are closed, cutting the city off from the rest of the world. The World Health Organization (WHO) prolongs its meeting due to the lack of information communicated by China.

“The decision whether or not to declare a public health emergency of international concern is a decision that I take very seriously and that I am only prepared to take with due regard to the available evidence,” the director told the press. WHO, Tedros Adhanom Ghebreyesus, in Geneva, Switzerland.

For their part, scientists are continuing their investigations to better understand this previously unseen strain. A research team from the Beijing Medical University published a study in the Journal of Medical Virology on January 22. These researchers believe they have identified the origin of this epidemic which worries the whole world: snakes.

2019-nCoV, resulting from a recombination, would come from snakes

Coronaviruses are rather common in mammals and birds, especially in species close to humans such as pigs, cats, rats or poultry. To trace the origin of the virus, Chinese scientists compared more than 200 genomes of animal-infected coronaviruses with that of 2019-nCoV.

By comparing the genetic sequences which are specific to the host of the virus by bioinformatics, it appears that snakes are the most probable reservoir among all the species studied.

In addition, the genome of the Wuhan coronavirus was born from the recombination of two coronaviruses: one known to infect bats and the other with unknown origins. Some of these proteins therefore differ from those of its “parents”.

This is the case with a surface glycoprotein which allows the entry of the virus into other cells. This change would have allowed 2019-nCoV to cross the species barrier to infect humans.

2019-nCoV, an emerging zoonosis ?

The zoonosis track has been favored by scientists, because the epidemic has broken out in a food market in Wuhan. As a reminder, a zoonosis is a viral, bacterial or parasitic animal disease, capable of infecting humans following a mutation.

But what is the connection between snakes and a fish market? According to the authors, snakes are commonly found for sale on the stalls of this market, in particular the species Bungarus multicinctus and Naja atra which live in the region.

It is the first study to identify a potential reservoir for Wuhan coronavirus. Other species, also abundant at the Wuhan market, will also be investigated.