When the Covid-19 pandemic was declared by the World Health Organization (WHO) in March 2020, almost two years ago, a group of researchers, including in China, were already monitoring the development of a virus called Langya that was beginning to infect humans. .

Now, in a study published in the New England Journal of Medicine, the group announces that the new pathogen, Langya henipavirus (LayV), was identified in 35 people in Shandong and Henan provinces and showed some symptoms similar to those seen in the first phase of Covid. causes symptoms such as high fever, fatigue and cough.

The researchers, led by Xiao-Ai Zhang and Hao Li, both from the Beijing Institute of Microbiology and Epidemiology, reported that the samples collected in the Langya study were too small to determine whether or not there was human-to-human transmission, but they do not exclude this hypothesis.

In the article, they indicate that this is a discovery that merits further investigation of the Langya virus to better understand the human disease associated with it, and signal the importance of remaining vigilant to prevent a new epidemic. The opinion is shared by Werciley Júnior, Infectious Diseases Coordinator at Hospital Santa Lúcia, in Brasília. The new virus is limited to regions in China but could reach other parts of the world, he said.

According to Chinese health authorities, the Langya-infected patients were not in close contact, suggesting that human infections may be sporadic. The team followed patients from popular hospitals in China between April 2018 and August 2021 to track suspected zoonotic diseases (transmitted from animals to humans). Individuals with acute fever (above 38°C) and a history of animal exposure within 1 month before the onset of complications were included in the study.

Blood tests and throat secretions indicated the new Langya virus. There are two other pathogens of the same genus – Hendra henipavirus (HeV) and Nipah henipavirus (NiV) – which present high lethality in severe infections. There were no deaths or serious complications in the cases presented in the New England Journal of Medicine. The symptoms of those infected were fever (100 of the patients), fatigue (54), cough (50), anorexia (50), muscle pain (46), nausea (38), headache (35) and vomiting (35). 

After identifying LayV, the team conducted an epidemiological survey of infected patients and their close family members using a standard questionnaire that included pre-illness exposure history, demographic data, and pre-existing underlying illnesses. The team found that transmission may have occurred through infected animals or fruit.

Wild and domestic experiments 

in 25 species of wild animals suggest that the shrew – a mouse-like mammal – could be a natural reservoir of LayV. There have also been cases of infection in domestic animals, such as dogs and goats, from some infected people. Analysis of the virus's genome indicates that it has a genomic organization identical to that of other henipaviruses known to infect humans and cause deadly diseases.

This is the first time that LayV has been identified in humans. Therefore, there is no specific treatment for this infection. There are therapies being tested for other henipaviruses. Researchers at the University of Washington, in the United States, published in Science in March that they discovered details of how Nipah and Hendra attack the cells and immune responses that try to combat this infection, opening space for new therapeutic fronts. including vaccines.

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