Scientists have found 20 previously unknown viruses in bats from China’s Yunnan province, including two that are closely related to Nipah and Hendra viruses, both known to cause deadly infections in humans.

The discovery, published in the journal PLOS Pathogens on Tuesday, has renewed focus on the potential risks of diseases that can jump from animals to humans, especially as people and wildlife increasingly share the same spaces.

The newly discovered viruses were found in fruit bats living near orchards and villages, areas where there is a higher chance of contact between bats, people, and farm animals.

Scientists from China and the University of Sydney examined kidney samples from 142 bats, collected over a span of four years. They identified a total of 22 viruses, out of which 20 were completely new. Two of them are henipaviruses, the same family that includes Nipah and Hendra viruses known for causing severe brain inflammation and respiratory illness in humans, with fatality rates up to 75%.

While many studies focus on bat feces to study viruses, this research looked at bat kidneys. Kidneys are responsible for producing urine, and researchers believe that virus shedding through urine could be a key, and often overlooked, transmission path.

The study found that these henipaviruses were in bats living near farmland, where contaminated urine could land on fruit that is later eaten by people or livestock, creating a potential pathway for infection.

The researchers also discovered two new types of bacteria and one unknown parasite, making the study even more important in understanding the hidden risks bats may carry.

Experts say the findings are important, but more work is needed to understand how dangerous these new viruses are.

“This study highlights that we know very little about the viruses that infect bats and those that exist in our world more generally,” said Tim Mahony, director at the Centre for Animal Science at Australia’s University of Queensland, who was not involved in the study.

Linfa Wang, a professor at the Duke-NUS Medical School, added: “This discovery basically further confirms the diversity of bat viruses in general and henipaviruses in particular. My overall assessment is that we need to watch closely, but not be overly concerned at the present time.”

Though the study was published in a respected journal, one of the main researchers declined to speak in detail, saying in an email to Bloomberg that the topic is “quite sensitive” due to its political nature.

The authors of the study warned in their report that the findings “underscore critical zoonotic threats,” calling for urgent attention to viruses that could jump from bats to humans or farm animals.

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