New Langya virus discovered in China could be ‘tip of iceberg’, researchers warn

HONG KONG (CNN) — A new virus detected in dozens of people in eastern China may not cause the next pandemic, but it suggests how easily viruses can slip from animals to humans, and scientists have warned that more vigilance is needed.

The virus, called Langya henipavirus, has infected nearly three dozen farmers and other residents, according to a team of scientists who believe it may have spread to people directly or indirectly through small mole-like mammals found in a variety of habitats.

The pathogen has not caused any deaths, but was detected in 35 unrelated flu patients in hospitals in Shandong and Henan provinces between 2018 and 2021, the scientists said. The discovery comes as scientists warn that animal viruses continue to spread undetected among people around the world.

“We are greatly underestimating the number of these zoonotic cases in the world, and this (Langya virus) is the tip of the iceberg,” said emerging virologist Leo Boon, a professor at the University of Public Health in Hong Kong. , who was not involved in the recent study.

The first scientific research on the virus has been published in a letter from a team of Chinese and international researchers New England Journal of Medicine Last week, it gained global attention due to increased concern over disease outbreaks. Nearly three years after the novel coronavirus behind the current pandemic was first identified in China, hundreds of thousands of new Covid-19 cases are being reported every day around the world.

However, the researchers say there is no evidence that Longya virus is spreading among people or has caused local outbreaks of linked cases. They added that further studies on a larger subset of patients are needed to rule out person-to-person transmission.

Linfa Wang, a senior emerging infectious disease scientist who was part of the research team, told CNN that the new virus is unlikely to evolve into “another one.”Disease XAs a previously unknown pathogen instigating an epidemic or pandemic, “such secondary zoonotic events demonstrate that they occur more frequently than we think or know.”

To reduce the risk of the emerging virus becoming a public health crisis, it is “absolutely necessary to carry out active surveillance in an international, transparent and collaborative way,” said Wang, a professor at the National University of Medicine’s School of Medicine. Prince of Singapore.

Following the trail of a new virus

The first clues to the presence of the new virus emerged when a 53-year-old female farmer was treated at a hospital in Qingdao, Shandong province in December 2018 with symptoms including fever, headache, cough and nausea. Research papers.

Because the patient indicated that he had contact with animals in the past month, he was included in additional evaluation performed at three hospitals in eastern China for the diagnosis of zoonotic diseases.

When they examined the test samples from this patient, the scientists found something unexpected: a never-before-seen virus related to Hendra and Nipah viruses, deadly pathogens from a family not generally known for bacteria to spread easily.

Over the next 32 months, researchers at three hospitals tested the same number of patients for the virus, ultimately finding it in 35 people who had multiple symptoms, including cough, fatigue, headache and nausea, and fever.

Nine of those patients were infected with a known influenza-like virus, so the source of their symptoms is unclear, but the researchers believe the remaining 26’s symptoms may have been caused by the new henipavirus.

Some showed severe symptoms, such as pneumonia or abnormalities of thrombocytopenia, according to Wang, but their symptoms were far from those seen in Hendra or Nipah patients, and no one in the group died or was admitted to the unit. Intensive treatment. He added that although all recovered, they were not being monitored for long-term problems.

Of that group of 26, all but four were farmers, and while some were flagged for cases first diagnosed by the same hospital, many were found in Xinjiang, 700 kilometers (435 miles) away in Henan.

Wang explained that since similar viruses have been known to spread in animals from southwest China to South Korea, it would not be “surprising” to see it spread over long distances to humans.

There was “no close contact or common exposure history between patients” or other indications of person-to-person transmission, Wang and colleagues wrote in their findings. This suggests that the cases were sporadic, but more research is needed, they said.

When they learned that a new virus was infecting people, researchers, including Beijing-based scientists and Qingdao disease control officials, went to work to see if they could figure out what was infecting the patients. They examined domestic animals where the patients lived, and they found traces of past viral infections.

But the real breakthrough came when they examined samples taken from small wild animals caught in traps and found 71 infections in two species of shrews, leading scientists to suggest that these small, rodent-like mammals may be where the virus naturally spreads.

It’s not clear how people got the virus, Wang said.

Further detection studies for Longya henipavirus will continue, he said, not only in the two provinces where the virus was detected, but more widely within China and beyond.

China’s National Health Commission did not immediately respond to a request for comment on whether surveillance for new virus infections is continuing.

Risk reduction

It is universally believed that 70% of emerging infectious diseases They passed to humans through contact with animals, a phenomenon scientists say has been accelerated by growing human populations encroaching on wildlife habitats.

China has seen major outbreaks of emerging viruses in the past two decades, including SARS and Covid-19 in 2002-2003, both of which were first identified in the country, and viruses believed to have originated in bats.

The devastating effects of two diseases, especially Covid-19, which has killed more than 6.4 million people worldwide to date, demonstrate the importance of quickly identifying cases of new viruses and sharing information about them.

Scientists not involved in the new research acknowledged that more work is needed to understand Langya virus and to confirm the latest findings, which underscore the importance of monitoring which viruses can spread from animals to people.

“Since it (the new henipavirus) may not be confined to China, it is important to share this information and allow others to prepare or do further research in their own countries,” Boon said in Hong Kong.

Scientists say important questions remain to be answered, including how widespread the new virus might be in the wild, how it spreads to people and how dangerous it is to human health, whether it has the potential to spread between people, or how you acquire this ability, as the jump from animals to humans continues.

The geographic range in which infections have been detected “suggests that the risk of this infection is very widespread,” said Malik Peiris, a virologist at the University of Hong Kong, adding that studies in other parts of China and in neighboring countries are important. Geographical range of this virus in animals (shrews) and humans”.

He pointed out that the latest findings point to undiagnosed infections transmitted from wildlife to humans and that systematic studies are needed to understand the comprehensive picture of not only this virus but also human infection by wildlife viruses.

“This is important so we don’t catch the next epidemic when it comes,” he said.