Scientists raise 'urgent concerns' over new bat viruses discovered in China

 Researchers have raised "urgent concerns" after discovering two new bat viruses in China with the potential to infect humans and cause severe brain inflammation and respiratory disease.

The viruses, along with multiple new bacteria and parasite species, were discovered in bats inhabiting orchards in southwestern China's Yunnan province, according to a study published on Tuesday in the journal PLoS Pathogens.

These viruses are closely related to the deadly Nipah and Hendra pathogens, which cause severe brain inflammation and respiratory disease in humans, according to researchers, including from the Yunnan Institute of Endemic Disease Control and Prevention.

Nipah is a lethal pathogen known to cause severe disease in humans, including acute respiratory distress with a high mortality rate of 35-75 per cent.

The Hendra virus has been responsible for multiple fatal outbreaks in humans and horses.

"These viruses are naturally hosted by fruit bats and are typically transmitted to humans through bat urine or saliva, often via contamination of food sources," researchers said.

The study raises concerns about the potential for similar new viruses to spread from bats to livestock or humans in the region.

"This finding is particularly significant as Yunnan province is a recognised hotspot for bat diversity," it notes.

Due to their unique immune systems, bats are a natural reservoir for a wide range of microorganisms, including notable pathogens transmitted to humans.

While the exact origins of the Covid-19 pandemic remain unclear, numerous studies suggest horseshoe bats as one of the most likely host candidates from which the novel coronavirus jumped to humans.

However, the complete array of viruses, fungi, bacteria and parasites that infect bats remains unknown as most previous studies have focused on faeces from the flying mammal alone without inspecting the organs.

The latest study peered inside the kidneys of 142 bats from 10 species, which were collected over four years across five areas of Yunnan.

Genome sequencing of the samples revealed 22 viruses, of which 20 are new to science.

Two of these were henipaviruses, the same genus as Nipah and Hendra, which have had high fatality rates in humans in previous epidemic outbreaks.

Since these viruses can potentially spread through urine, scientists raise concerns about the risk of these pathogens jumping to humans or livestock via contaminated fruit from the orchards.

The findings underscore the need for a multi-organ screening approach to understand the microbial diversity harboured by bats.

Scientists call for "comprehensive, full-spectrum microbial analyses of previously understudied organs to better assess spillover risks from bat populations".

"By analysing the infectome of bat kidneys collected near village orchards and caves in Yunnan, we uncovered not only the diverse microbes bats carry, but also the first full-length genomes of novel bat-borne henipaviruses closely related to Hendra and Nipah viruses identified in China," they say.

The Independent