‘New coronavirus originates from bats too, not from snakes’

Researchers at Utrecht University conclude

The new coronavirus has been identified in more than 2700 people, and 81 patients now have died. What is the coronavirus actually, and are we in danger in the Netherlands? We put these questions to researchers Berend-Jan Bosch and Raoul de Groot, both virologists at Infectious Diseases and Immunology (Faculty of Veterinary Medicine). Together with their colleagues, they are researching coronaviruses.

What are coronaviruses? 

‘Coronaviruses are common all over the world – they form a large family of viruses that can cause diseases in many animal species. In farm animals, coronaviruses create problems such as growth inhibition and death. The Porcine Epidemic Diarrhoea Virus, for instance, causes serious diarrhoea and death in piglets. In Asia and America, this virus is leading to major losses in the pig industry, and the poultry sector all over the world is also suffering from the consequences of infections caused by coronaviruses. In humans, luckily, coronaviruses mostly only cause colds. But coronaviruses that make the jump from animals to humans can indeed cause serious illnesses. We saw this with the SARS and MERS coronaviruses, which have caused serious respiratory illnesses in people in recent times.

‘The new coronavirus, provisionally described as nCoV-2019, belongs to the same virus family as the SARS virus. Both viruses occur in many variants in various species of bat. The new virus, too, causes serious infections of the lower respiratory tract (pneumonia) with potentially fatal consequences. Moreover, both viruses use the same receptor to penetrate their host cell, but there are also important differences between the new virus and the original SARS virus, which means it’s still unclear in what manner and how fast this virus spreads and how dangerous it is to humans.’ 

What’s the source? And what’s the link between animals and humans? 

‘This virus almost certainly derives from bats, and it is genetically almost identical to a virus that has previously been found in bats. But we still don’t know if this virus came to us straight from bats or via another mammal. The story currently doing the rounds that the virus comes from snakes is unfounded, and isn’t backed up by the analysis of the genetic material.’ 

How does the virus spread? 

‘The virus spreads from person to person, presumably through the air. The efficiency of transmission still can’t be determined with certainty. It’s not yet known whether there are other pathways of infection, such as through indirect contact with contaminated materials.’ 
What role are the researchers at Utrecht University playing? 
‘We have previously researched SARS and MERS. We have made an important contribution to the development of diagnostic tests, to identifying and analysing protective antibodies. We have also investigated which host molecules they use and how an infection occurs. Initiatives for using our expertise for nCoV-2019 as well have now begun.’ 

Are we in danger? 

‘Not for the time being. The outbreak is still at a very early stage, and it’s not clear how things will develop. Hopefully, the measures will have an effect and the epidemic can be supressed, but we can’t rule out the possibility that the virus will spread and lead to a global epidemic. The coming weeks and months will be decisive.’

Computeranimatie van een coronavirus. Het coronavirus, rood, dringt hier binnen in de gastheercel, blauw. Hiervoor bindt het oranje eiwit zich aan het blauwe molecuul op het oppervlak van de gastheercel. Dit is de eerste stap in de infectie.
In this image, the coronavirus, red, penetrates the host cell, blue. To achieve this, the orange protein binds to the blue molecule on the surface of the host cell. This is the first step in the infection.