Langya genipavirus: New virus discovered in China could be ‘tip of the iceberg’ for unknown pathogens, researchers say

The virus, dubbed Langya henipavirus, has infected nearly 30 farmers and other residents, according to a group of scientists who believe it may have been spread directly or indirectly. to humans from shrews, small, mole-like mammals that live in a variety of habitats.

The scientists said the pathogen did not cause any deaths but was found in 35 patients with unrelated fever at hospitals in Shandong and Henan provinces between 2018 and 2021. in people all over the world.

“We greatly underestimate the number of these zoonotic cases in the world, and this (Langia virus) is just the tip of the iceberg,” said new virus expert Leo Poong, a professor at the School of Public Health at the University of Hong Kong. who did not participate in the latest study.

However, the researchers say there is no evidence that the Langya virus is spreading between people or that it has caused a localized outbreak of related cases. They added that more research is needed in a larger subset of patients to rule out human-to-human transmission of the virus.

Veteran emerging infectious disease scientist Lingfa Wang, who was part of the research team, told CNN that while the new virus is unlikely to turn into “another virus.”disease Xan “event”, such as a previously unknown pathogen causing an epidemic or pandemic, “this demonstrates that such zoonotic side effects occur more often than we think or know.”

To reduce the risk of an emerging virus escalating into a health crisis, “it is absolutely essential to conduct active surveillance in a transparent and collaborative international manner,” said Wang, a professor at Duke National University Singapore’s School of Medicine.

Tracking a new virus

The first signs of the novel virus emerged when a 53-year-old farmer sought medical attention at a hospital in Qingdao city, Shandong province, in December 2018, with symptoms including fever, headache, cough and nausea. researchers.

Because the patient reported having been in contact with animals within the past month, she was included in an additional screening at three hospitals in eastern China to detect zoonotic diseases.

When the patient’s test samples were examined, scientists discovered something unexpected – a virus never seen before associated with the Hendra and Nipah viruses, extremely deadly pathogens from a family not normally known for its ease of spread from person to person.

Over the next 32 months, researchers at three hospitals screened similar patients for the virus, eventually finding it in 35 people who had a range of symptoms in addition to fever, including cough, fatigue, headache and nausea.

Nine of these patients were also infected with a known virus, such as the flu, so the source of their symptoms was unclear, but the researchers believe that the symptoms in the remaining 26 may have been caused by the new genipavirus.

Some showed severe symptoms such as pneumonia or thrombocytopenia abnormalities, platelet status, according to Wang, but their symptoms were very different from those seen in Hendra or Nipah patients, and no one in the group died or was admitted to the intensive care unit. He added that although they all recovered, they were not observed to have long-term problems.

Of this group of 26, all but four were farmers, and while some were reported by the same hospital as the original case, many more were found in Xinyang, more than 700 kilometers (435 miles) from Henan province.

Because similar viruses have been known to circulate among animals from southwestern China to South Korea, it is “not surprising” to see spread among humans over such large distances, Wang explained.

In their findings, Wang and colleagues wrote that “there was no close contact or shared history of infection among patients” or other evidence of person-to-person transmission. This suggests that the cases have been sporadic, but more research is needed, they say.

Once they learned that the new virus was infecting people, the researchers, which included Beijing scientists and Qingdao disease control officials, set to work to see if they could uncover what was infecting patients. They tested the pets the patients had lived in for signs of past infection with the virus and found a small number of goats and dogs that may have previously had the virus.

But the real breakthrough came when they tested samples taken from small, trapped wild animals and found 71 infections in two species of shrews, leading scientists to speculate that these small, rodent-like mammals may be the site of natural circulation of the virus.

It remains unclear how the virus got to humans, Wang said.

This will be followed by further screening studies for Langya henipavirus, which should be carried out not only in the two provinces where the virus was found, but also on a larger scale in China and beyond, he said.

China’s National Health Commission did not immediately respond to a request for comment on whether monitoring of new cases of the virus was ongoing.

Risk Reduction

globally, 70% of emerging infectious diseases They are thought to be transmitted to humans through contact with animals, a phenomenon scientists say has accelerated as growing human populations expand into wildlife habitats.

Over the past two decades, China has experienced major outbreaks of new viruses, including SARS in 2002-2003 and Covid-19, which were first identified in the country and are caused by viruses thought to have originated in bats.

The devastating impact of both diseases, especially Covid-19, which has so far killed more than 6.4 million people worldwide, demonstrates the importance of quickly identifying cases of new viruses and sharing information about potential risks.

Scientists not involved in the new study agreed that more work is needed to understand the Langya virus and confirm the latest findings, and said the finding highlights the importance of keeping track of which viruses can be transmitted from animals to humans.

“Because this (new genipavirus) may not only be circulating in China, it is important to share this information and allow others to prepare or conduct further investigation in their countries,” Poon said in Hong Kong.

Scientists say important questions need to be answered about how widespread a new virus can be in nature, how it enters people and how dangerous it is to human health, including the possibility of it spreading between people or gaining this ability if it continues to pass from animals to people.

The geographic coverage in which infections have been found “suggests that this risk of infection is fairly widespread,” said virologist Malik Peiris of the University of Hong Kong, adding that studies in other countries in China and neighboring countries are important “to establish the geographic range.” of this virus in animals (shrews) and in humans.

He also said the latest findings point to a large number of undiagnosed infections being transmitted from wildlife to humans and the need for systematic research to understand not only this virus, but the broader picture of human infection with wildlife viruses.

“It is important that we are not caught off guard by the next pandemic when – not if – it comes,” he said.

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