Scientists are on alert as a new virus spreads in eastern China – reportedly infecting dozens of people and bearing some eerie similarities to COVID-19.

The novel Langya henipavirus (LayV) has reportedly infected 35 people in China’s Shandong and Henan provinces.

According to a study published by the Beijing Institute of Microbiology and Epidemiology, the cases were identified after patients with high fevers were examined by health officials.

Like COVID-19, the virus is believed to have spread from animals to humans, in this case from wild shrews.

But a leading Australian epidemiologist has urged caution, saying Langya’s emergence isn’t necessarily cause for concern.

Importantly, it is ‘‘highly unlikely’’ to spark another pandemic.

What is the Langya virus?

Langya was formally named by scientists this week, although it was first detected in routine surveillance in December 2018.

It belongs to the henipavirus family, which also includes the nipah virus and the hendra virus.

The hendra virus is a rare bat-borne disease that emerged among horses in Queensland in the 1990s.

Nipah is also rare, with occasional outbreaks in Asia since the 1990s.

Although the World Health Organisation is yet to comment on the Langya, it acknowledges that viruses within the henipavirus family have high fatality rates.

Nipah, for example, has an estimated case fatality rate of 40 to 75 per cent for people – far higher than the death rate for COVID-19.

Hendra virus has also proven deadly. It has killed 14 horses, and has an approximate human fatality rate of 70 per cent.

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What are its symptoms?

All those who have so far contracted the Langya virus have had fevers and flu-like symptoms, which are similar to those from the coronavirus.

Other symptoms included fatigue, cough, loss of appetite, body and muscle aches, and queasiness.

On a positive note, the effects of Langya appear to have been mild. So far, no one is known to have died from it.

A few patients have reportedly suffered liver and kidney problems – though how severe they were was not revealed.

A co-author of the study told China’s state-run outlet Global Times that the Langya cases had ‘‘not been fatal or very serious’’ and said there was ‘‘no need for panic’’.

How is it transmitted?

Langya henipavirus is a zoonotic disease, which means it is transmitted from animals to humans.

All the 35 infected patients in China reported recent exposure to animals, meaning they likely caught Langya from them.

Researchers also found the virus in four of 79 domestic dogs, and three of 168 goats.

There is no evidence to suggest that Langya henipavirus can be transmitted between humans, although the researchers said their sample size was too small to rule that out as a possibility.

The virus is believed to have initially spread to humans from wild shrews. Photo: Getty

Should we be worried?

With cases not yet detected outside the two eastern Chinese provinces, Langya has not spread far in the two-and-a-half years since it was first detected.

University of South Australia professor of biostatistics Adrian Esterman said it wasn’t unusual for new viruses to be discovered.

‘‘There’s well over 200 viruses that cause disease in man, and probably more that we’re not aware of,’’ Professor Esterman said.

‘‘We actually discover three or four new ones every year. So this is not unusual.’’

Professor Esterman said there were some uncanny similarities with COVID-19, but that didn’t necessarily mean another pandemic was on the horizon.

‘‘When we hear reports [of a new virus] from China, saying there’s no human transmission, we look at it with a bit of a jaundiced eye,’’ he said.

‘‘I honestly don’t think there’s any cause for panic or concern at the moment. Theoretically, it could mutate between humans. And theoretically, it could cause another pandemic. But I think it’s highly unlikely.’’

Why are we seeing so many zoonotic viruses?

Langya virus is also just the latest virus to make the leap from animals to humans.

COVID-19, which sparked the worldwide pandemic that continues more than two years later, is thought to have originated in wet markets in China.

Monkeypox, as the name suggests, is thought to have originated in monkeys (although the WHO is careful to state the latest outbreak around the world is not linked to them).

The US Centres for Disease Control estimates that three in four newly discovered viruses are due to transmission from animals to humans.

Professor Esterman said there had been a recent increase in zoonotic viruses, which he attributed to two key factors.

‘‘The first one we can think of is climate change. So [due to] different climatic conditions across the world, like floods, droughts, bushfires, we’re coming in more contact with animals that can transmit diseases to humans,’’ he said.

‘‘We’re seeing vast swathes of the Amazon being chopped down for logging, etc. And again, that brings us into contact with bats and other creatures that live in the treetops.’’

The second, Professor Esterman said, was the notorious wet markets, found in parts of Asia.

‘‘For all these reasons, we’re seeing an increasing number of pandemics. Unless we do something about all these things, this will keep happening.’’