- Mariana Alvim
- BBC Brazil correspondent, Sao Paulo
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Research suggests that shrews may be an animal host for the virus.
An international team of scientists has announced the discovery of a new virus from the Henipavirus family, which is known to cause outbreaks of extremely deadly infections in humans.
Between 2018 and 2021, the research team said, the “Langia hnipa virus” (Live, commonly known as “Langia virus”) infected at least 35 people in China.
In a letter published August 4 in the New England Journal of Medicine, the scientists wrote that there was no indication that the “Langia virus” could be transmitted through human-to-human contact. They also suggested that the source of the infection might be from an animal – the team found evidence that shrews may be the natural reservoir of the virus, but more research is needed to confirm this.
Of the 35 cases identified in China, 26 were carefully studied. The study revealed that all patients had fever and some cases were accompanied by symptoms such as fatigue (54%), cough (50%), headache (35%) and vomiting (35%). Scientists also found some abnormalities in liver function (35% of patients) and kidney function (8%). But there is no information on any deaths yet.
Experts interviewed by the BBC say the discovery of a new virus does not necessarily mean a new pandemic. But the discovery of a new virus in the family Henipaviridae is worrisome because other pathogens in this family have previously caused severe outbreaks and infections in Asia and Oceania.
There are no hotspots.
These outbreaks are caused by its ‘cousins’ Langia virus, Hendra henipavirus, referred to as HeV and Nipah virus (referred to as Nipah virus, referred to as NiV). Hendra virus is rare, but has a mortality rate of 57 percent, according to the Centers for Disease Control (CDC).
In the case of Nipah virus, it had a mortality rate of 40-70% in the outbreaks reported from 1998 to 2018. Both viruses can cause respiratory and nervous system problems.
India suffered its worst outbreak of the Nipah virus in 2018, with 17 deaths out of 19 confirmed cases in the Indian state of Kerala.
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China discovers cases of infection among some patients who come to hospital with fever (file photo)
It is difficult to compare this data with the Covid-19 mortality rate due to the use of different methods and differences in data provided by different countries and over time. However, it can be argued that the lethality rate of Hendra virus and Nipah virus at the time of the outbreak was much higher than the novel coronavirus epidemic that first broke out in China in December 2019.
Jansen de Araujo, a professor at the Laboratory for Research in Emerging Viruses at the University of São Paulo, believes that the discovery of the “Langia virus” does not mean the beginning of a new epidemic, because the researchers who discovered the new virus were monitoring it. For a long time.
“What is being observed is not a hot spot (where there is an increase in the spread of disease) like Covid-19,” said Professor Araujo. It is different from the virus that causes Covid-19, which is spreading very quickly around the world.
Ian Jones, professor of virology at the University of Reading in the UK, noted that the “Langia virus” has not yet been shown to be able to transmit effectively from person to person.
‘No clear sign of a mutation’
Prof Jones told the BBC: “Importantly, neither Hendra nor Nipah showed signs of an epidemic.”
Professor Jones added: “There is no clear sign that it is turning out to be more transmissible, and there is some suspicion that this will also be the case with Langia virus.”
However, both experts see the need to continue monitoring new cases.
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The Nipah virus is a “cousin” of the new Langia virus.
The team that discovered the “Langia virus” reported that all of the infected patients were residents of Shandong and Henan. There was no close contact between these patients and there was no history of passing from the same places. The researchers tracked the contacts between the nine patients and their relatives, and did not find any cases of infection that could prove the transmission of infection from one person to another.
More than half of those infected were farmers, which is relevant given that the virus was transmitted through some form of contact with animals.
When trying to look for genetic traces of “Langia virus” in domestic and young wild animals, the scientists found that shrews had the highest detection rates for the virus — more than 25 percent of shrew scans found them to carry traces of the virus. The team thinks shrews may be the “natural host” of the virus – animals that are infected with the pathogen, but don’t get sick themselves, unlike their definitive hosts, like humans.
bat host
Hendra virus, Langia “cousins” virus, and Nipah virus are known to use bats as their natural hosts. The Centers for Disease Control and Prevention says there are no known human cases of Hendra virus transmission, but people can become infected through contact with body fluids, soft tissues, or feces of infected horses.
On the other hand, Nipah virus is known to be transmitted through contact with infected animals, such as bats and their bodily fluids, or through close contact with infected people.
Dr. Michele Lonardi, an animal virologist at Londrina State University in Brazil, and colleagues have published a 2021 review of research on the hanniba virus. The authors note that there are currently no known treatments for human infection with Hendra and Nipah viruses, and conclude that Nipah virus has “the potential to cause a devastating pandemic.”
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Fruit bats are known hosts for Henibaviridae viruses
However, Professor Jones sees no reason to panic.
He explained, “In my opinion, Nipah does not have a high risk of causing a pandemic. The risks posed by the virus to humans are understandable, but they can still be prevented through education rather than developing a vaccine, for example.”
Professor Jones also noted that what we currently know about the Nipah virus is that it replicates better in the human nervous system, making it less transmissible from person to person than the new coronavirus, which copies the virus in the respiratory tract.
“It is important not to panic when a new virus is discovered,” he said. “Scientists are always looking for new viruses, especially after Covid-19.”
“In the world there are many horrific viruses, but that does not mean that we will be exposed to them,” he said.
Note: Additional coverage of this article was written by Fernando Duarte
