This is a rather disturbing news coming from China: researchers have identified a new filovirus called Měnglà, from the same family of Ebola, which has all the inter-species transmission characteristics.
Filoviruses (Filoviridae), infectious agents that owe their name to their filamentous appearance, cause severe haemorrhagic fevers like Ebola. Up to now, there were eight species named after their place of origin (Zaire, Marburg, Tai Forest, etc.). But now researchers at the Duke-NUS Medical School in Singapore have discovered a new strain in a bat in China.
It is by performing genetic sequencing and characterization studies of filoviruses in bats that researchers have been able to identify this new virus. Named Měnglà, named after the district of Yunnan province in the south of China where it was found, it is a new kind of filovirus which joins the other three (Cuevavirus, Ebolavirus and Marburgvirus). This new category was named Dianlovirus, derived from the name diān which is the abbreviation of Yunnan.
The Měnglà virus shares only 32% to 54% of its genetic material with other filoviruses but shares several functional similarities to the Ebola and Marburg viruses. It encodes them for seven genes and uses the same molecular receptor, a protein called NPC1 that the virus uses to enter the cell and cause an infection. In addition, it is likely to replicate with other Ebola or Marburg genetic sequences, which could lead to the formation of new viruses. The researchers tested the Měnglà virus on cell lines of different species (humans, monkeys, dogs, hamsters and bats) and found that, like other filoviruses, it presents “a potential risk of interspecies transmission”.
The Měnglà virus has so far only been detected in bat species, which is the main reservoir for most filoviruses. But if the infection actually reaches humans, it could have “devastating” consequences, says Professor Wang Lin-Fa, lead author of the study published in the journal Nature Microbiology. Recall that Ebola is one of the most deadly diseases in the world, with a death rate of 50% to 70% in patients with a very strong contagious capacity. The 2014-2016 epidemic in West Africa has caused more than 11,000 deaths according to WHO. So far, China has not yet been affected by such an outbreak, but the country seems to be in a new outbreak of infectious virus. The Reston strain has been identified in monkeys and pigs.
“With the rise of globalization, early identification of viruses is essential in identifying and preventing the risk of infectious diseases,” says Professor Patrick Casey, Senior Vice Dean, Research, Duke-NUS Medical School. In July 2018, a new Ebola-type filovirus named Bombali had already been discovered in Sierra Leone in two bat species. “I think that we will still see many virus families emerging from the study of bats,” said Jeremy Farrar, president of the British Wellcome Trust Foundation.