Scientists in China have reported the discovery of a new virus , called Langya. The microorganism belongs to the Henipavirus genus of the Paramyxoviridae family. There have been 35 reported human cases occurring in provinces in China between 2018 and 2021.
Similar viruses such as Hendra and Nipah are known to infect humans and cause fatal diseases. However, in the current study, no deaths associated with the infection were described. The findings were published in the scientific journal New England Journal of Medicine (NEJM) on the 4th of August.
Faced with the emergence of a new virus capable of causing infections in humans, memory takes us to the scenario of late 2019, when cases of pneumonia of unidentified origin, which came to be defined as Covid-19, began to appear in China. .
To clarify what is already known about the Langya, the CNN talked to Brazilian scientists who carry out surveillance and study of the most different types of viruses. Here are some clues about the characteristics and risks of the new microorganism.
What the article published in NEJM says
The first case of human infection with the new virus was detected during surveillance of patients with fever who had a recent history of contact with animals in eastern China. The researchers identified that it was a new virus from viral isolation and analysis of genetic information.
According to the study, the genome of the Langya virus (LayV) is similar to that of other henipaviruses, such as Hendra and Nipah, with greater resemblance to a henipavirus called Mojiang, discovered in southern China.
From the initial discovery, the scientists carried out further investigations that led to the identification of a total of 35 infected patients in Shandong and Henan provinces, China. Of this group, 26 were infected with Langya alone, with no other disease-causing agent present.
These 26 patients had symptoms such as fever (100% of patients), fatigue (54%), cough (50%), anorexia (50%), muscle pain (46%), nausea (38%), headache (35%). %) and vomiting (35%). Symptoms were accompanied by a drop in platelets (35%) and white blood cells (54%), as well as abnormalities in liver (35%) and kidney (8%) functions.
In order to identify the possible host of the virus, also called a reservoir, the researchers carried out a serological investigation of domestic animals and small wild animals.
The data show that, of the 25 wild species analyzed, the RNA of the new virus was detected mainly in shrews, which are small mammals, suggesting that they may be a natural reservoir of the virus. Langya virus was also less significantly identified in goats and dogs.
Risk of new pandemic low, experts say
The study points out that no person-to-person transmission of the virus has been identified which suggests that human-to-human infection may be sporadic.
“Contact tracing of 9 patients with 15 close family members did not reveal close-contact transmission of LayV, but the sample size was too small to determine the status of human-to-human transmission for LayV,” the article reads.
For the researchers, the fact that cases have been recorded over a long period of time suggests that transmission does not occur routinely, as in the case of Covid-19, which showed a rapid and significant increase in infected.
“We have good news, there are about 35 people who have had a positive diagnosis for the virus, some with liver and kidney complications, but no deaths reported in a relatively long period, with no reports of transmission between humans, this point is something that reassures”, says virologist Fernando Spilki, a researcher at the Feevale University, in Rio Grande do Sul.
“Some circumstances mean that we are not really afraid of the Covid-19 pandemic. Langya is not exactly a highly infectious virus, so much so that these 35 cases, 26 of which are well studied, took place over more than three years, since 2018. Researchers have been following cases of this infection, it is not the same as Covid-19, which, suddenly, there was an explosion of cases”, adds researcher Flávio Fonseca, president of the Brazilian Society of Virology (SBV).
Researcher José Eduardo Levi, from the University of São Paulo (USP), assesses that the Covid-19 pandemic has awakened the alert of health authorities in several countries for the restructuring of diagnostic services and preparedness for new emergencies.
“Surveillance networks were set up, a test for this is Monkeypox. Here, we will assess whether it has improved diagnostic capability, which is critical for any emerging disease to know who is infected. Is the sequencing being done in an organized way, for example? This is proof of our immediate learning”, points out Levi.
Why Henipaviruses Cause Concern
Over time, scientists have observed that viruses from different genera of the Paramyxoviridae family have the ability to ‘jump’ between different species, spreading and establishing new niches.
Among the henipaviruses, Hendra and Nipah are the best known due to documented cases of animal and human deaths.
“This group, whose best-known representatives are actually Nipah and Hendra, which emerged in Asia and basically remained on the continent in terms of disease manifestation. The few outbreaks, whether in animals or humans, have mostly happened in Asia. These two viruses are characterized by a very strong neurological manifestation, an intense encephalitis with high lethality”, explains Fonseca.
According to the US Centers for Disease Control and Prevention (CDC), the natural reservoir of the Hendra virus has been identified as the flying fox (bats of the genus Pteropus). Since 1994 and as of 2013, Hendra virus infections in humans remain rare, with only seven cases reported.
“Henipaviruses refer to the Hendra virus, which caused deaths in horses in Australia in the 1990s, later it was discovered that it was related to a virus from bats that had reached horses through the common consumption of fruits and today it is a virus that is extremely observed,” says Spilki.
It is estimated that in the first Nipah outbreak people were likely infected by close contact with infected pigs. According to the CDC, person-to-person spread of the virus is reported in countries such as Bangladesh and India.
“The Nipah outbreak, which originates in a province in Asia, in pigs, causing a very high mortality. In humans, it enters from pigs, killing up to 50% of individuals who became infected at that time,” explains Spilki.
Surveillance
Scientists claim that there are no records of henipaviruses like Hendra, Nipah and Langya in the country .
In Brazil, the National Network for the Surveillance of Viruses in Wild Animals (Previr) carries out monitoring actions with the objective of detecting and analyzing viruses with potential for emergence in different Brazilian regions.
The project has the participation of researchers from Brazilian and foreign institutions, including specialists from the University of São Paulo (USP) and the Oswaldo Cruz Foundation (Fiocruz).
“This surveillance network is precisely to try to identify some viruses with zoonotic potential, in a faster way and even anticipate a possible fatality. We have collection teams in different parts of Brazil that collect samples of wild animals and we carry out specific tests for viral families, in order to identify the most important ones. We have targets, such as those of the Paramyxoviridae family, which would encompass Nipah, Hendra and this new virus”, says researcher Helena Lage Ferreira, one of the network’s coordinators.
Researcher José Eduardo Levi, from USP, says that the scientific community and society as a whole must seek ways to adapt to the emergence of new disease-causing agents.
“There is a whole argument that we are going to have more and more diseases. We are the most numerous large animal species, so any virus that adapts to humans, and especially for human-to-human transmission, does very well,” says Levi.
“There are seven billion to be infected, and these are people who move around a lot and are in close contact. In addition to environmental issues, the greater the impact on the destruction of the environment, the more man advances into the natural environment, the more chances of having these emergencies”, completes the researcher.
Source: CNN Brasil
