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An international team of scientists has identified a new virus that likely spread to humans after it first infected animals, in another possible zoonotic contagion less than three years after the coronavirus pandemic.
A peer-reviewed study published in the New England Journal of Medicine detailed the discovery of the Langya virus after it was observed in 35 patient samples collected in two eastern Chinese provinces. The researchers, based in China, Singapore and Australia, found no evidence that the virus was transmitted between people, citing in part the small sample size available. But they hypothesized that shrews, small mammals that subsist on insects, might have harbored the virus before it infected humans.
The first sample of the Langya virus was detected in late 2018 from a farmer in Shandong province who sought treatment for fever. About Over a two-year period, another 34 people were found to have been infected in Shandong and neighboring Henan, the vast majority of whom were farmers.
Subsequently, genetic sequencing of the virus showed that the pathogen is part of the henipavirus family, which has five other known viruses. Two are considered highly virulent and associated with high case fatality rates, according to the US Centers for Disease Control and Prevention. But none of the Langya patients died, the study indicated.
Among the 35 patients, 26 were found to be infected with Langya virus alone. All 26 had a fever, and about half had fatigue, low white blood cell counts, and a cough. More serious symptoms include impaired kidney and liver functions.
The researchers also tested Langya virus in 25 species of small wild animals. Their genetic material was “predominantly detected” in shrews, leading the team to suggest that the small mammals they are a “natural reservoir” of the virus.
Disease surveillance did not indicate common sources of exposure among those infected, nor did they come into close contact with each other, suggesting that human infection may have occurred “sporadically,” the researchers wrote.
Francois Balloux, a professor of computational systems biology at University College London who was not involved in the study, said the Langya virus does not appear to “look like a repeat of Covid-19 at all”. He noted on Twitter that the new virus is much less lethal than other henipaviruses and “probably does not spread easily from human to human.”
But this discovery serves as “another reminder of the looming threat caused by the many pathogens circulating in wild and domestic animal populations that have the potential to infect humans,” Balloux added.
Viruses that spread from animals to humans are not uncommon. About 70 percent of emerging infectious diseases in humans are zoonotic in origin, scientists say, and nearly 1.7 million undiscovered viruses may exist in mammals and birds. Hendra and Nipah viruses, two henipaviruses with high mortality rates, can be contracted through close contact with sick horses, pigs, and bats.
Scientists who study zoonotic diseases had warned even before the coronavirus pandemic that practices such as the unregulated wildlife trade, deforestation and urbanization have brought people closer to animals, increasing the odds of viral spread.
Karin Brulliard contributed to this report.
Source: www.washingtonpost.com