A team of researchers has uncovered a series of still unknown pathogens in the populations of battles in southwest China. Among them, twenty new viruses, some of whom have disturbing similarities with agents responsible for serious human diseases such as Hendra and Nipah viruses. These discoveries revive concerns about the potential for the transmission of new human animals viruses.
High -risk viral tanks
For years, bats have been identified as natural hosts of many viruses dangerous for humans. Recently, researchers have documented the existence of coronavirus in certain Japanese species which, with a mutation, could infect humans.
In this new field work, carried out between 2017 and 2021 in the province of Yunnan, scientists analyzed renal tissue samples on 142 bats belonging to ten different species. Their objective is to explore a still little studied part of the bat microbiome, namely the microbes present in their kidneys.
The results of their analyzes, published in the journal PLOS Pathogensare surprising. They identified a total of 22 viruses, 20 of which are completely new. Two of them belong to the genre Henipavirusthe same as the Nipah and Hendra viruses, both classified as highly pathogenic.
Worrying similarities with deadly viruses
The genre Henipavirus Includes Nipah and Hendra viruses, responsible for serious diseases in humans. These infections, although rare, cause respiratory and neurological disorders that can be fatal. The NIPAH virus mortality rate is estimated between 40 and 70 % by the World Health Organization (WHO), while human infections by the Hendra virus, although rare, have a lethality rate greater than 50 %, according to the centers for the control and prevention of diseases (CDC) in the United States.
According to Dr. Vinod Balasubramaniam, a molecular virologist, the new discovered viruses have between 52 and 75 % of genetic similarity with the Hendra and Nipah viruses. This is a first, because no complete genome of Hénipavirus had never been identified in the Chinese bats before.
This fact highlights the potentially central role of Yunnan in the emergence of future zoonoses, due to its ecological characteristics close to those of the regions formerly affected by flambés of Nipah, like Malaysia.
An environment conducive to transmission
The bats studied lived in orchards near human dwellings. Since some Hénipavirus can be transmitted by bat urine, this raises concerns. Contaminated fruits or a potential intermediate host (such as livestock) could facilitate transmission to humans. We know, for example, that the Hendra virus has already been transmitted to humans via infected horses.
However, scientists call for caution. The simple fact that a virus is related to a known pathogen does not mean that it has an immediate danger to humans. “” It cannot be automatically concluded that these new viruses can infect other species “Recalls the veterinarian and ecologist Dr Alison Peel. She underlines that there are already viruses similar to Hendra and Nipah who have never proved to be transmitted to humans. Laboratory research will therefore be necessary to better understand the behavior of these new viruses and their zoonotic potential.
The study highlights the extent of the gaps in our knowledge of the microbes of bats. The discovery of the bacteria Flavobacterium yunnanensis and protozoan parasite Klossiella Yunnanensis Confirm that many remains to be learned about these animals and their potential impact on human health. The authors of the study emphasize the importance of extending microbial surveillance to other organs than the digestive system. This work provides valuable information on the infectious agents present in the kidneys of bats. In addition, here are 16 fascinating facts on bats.
