LayV, ‘new’ henipavirus, was found in China before Covid-19

Chinese researchers have detected a new henipavirus — the Langya henipavirus (LayV)—in routine surveillance examinations in febrile patients. After the first case, another 35 patients in Shandong and Henan provinces were identified with infections with the new virus, according to correspondence published in the scientific journal NEJM (New England Journal of Medicine) earlier this month.

If you are starting to get worried about the emergence of a new virus and dozens of cases identified, calm down. It is about a “new” linked to novelty and not to a temporal issue. The first case of LayV infection was documented before 2019, that is, even before the Covid-19 pandemic. The last reported are from 2021.

The situation with LayV, then, is nothing close to what the world has seen with the current Sars-CoV-2 pandemic, which, within a few months, was spreading across the globe.

“Nothing to take even a minute of sleep,” said virologist Maurício Lacerda, a professor at the Faculty of Medicine of São José do Rio Preto. “It’s nothing to worry about.”

Among all patients presented in the study, 26 were infected with LayV alone. Fever was present in all this portion with exclusive infection. More than half (54%) had fatigue and exactly half had a cough and loss of appetite. Other common symptoms were myalgia (46%), nausea (38%), headache (35%) and vomiting (35%).

It is likely that the source of people’s fever was infection with the virus, the study points out.

The researchers were able to find the virus also in goats and dogs. In wildlife, LayV was found especially in shrews (a small mammal), which could, the scientists say, be the natural reservoir of the new virus.

And here comes an important part: no signs of human-to-human transmission were observed. According to the researchers, there was no contact history or common exposure points among patients with the virus. Scientists even traced the contacts of nine patients and found no transmission within the group — small, it must be said.

Information from about two years of observations of the virus points to sporadic human infections, the authors say.

According to Nogueira, in recent years several new viruses have been discovered thanks to new identification tools.

In any case, of course, a new virus discovered in the country that had the record of the first cases of Covid can cause a certain feeling of discomfort in people. Nogueira warns, however, about the importance of virus surveillance carried out in China.

“Brazil does very little of this type of investigation. Do you think we don’t have similar things happening in Brazil? Of course we do. China is looking for new viruses, trying to understand what happens in their biodiversity, in their patients, in the population . It serves as a warning because Brazil stopped doing that”, says the Brazilian researcher.

Looking at nature is important precisely because of the risk of the so-called zoonosis spillover, that is, when a virus that occurs in animals manages to jump to another species, such as humans – deforestation can help in this spillover. This is the most likely origin for the Covid pandemic and for the detected cases of LayV.

These cases of LayV may also draw the attention of the scientific community because the virus belongs to the henipaviruses. Within this group are the quite lethal nipah and hendra viruses — whose natural reservoirs are commonly bats.

The outbreaks of both, until today, have been localized, even because of their aggressiveness and form of transmission, says Nogueira.

There is no record of human-to-human transmission of the hendra virus. In the case of the nipah, there is a record of transmission between humans. “There is great attention in the community for these viruses”, says the Brazilian scientist, who emphasizes that the case in question is not a cause for concern.