A new virus called “Langia” is believed to have infected 35 people in Shandong and Henan provinces, China for almost two years until 2021.
It is known to be associated with the Hendra and Nipah viruses that cause disease in humans. However, there’s a lot we don’t know about the new virus, known as LayV for short, including whether it spreads from person to person.
How do people get sick?
Researchers in China first discovered this new virus as part of routine surveillance of people with fever who reported recent contact with animals. Once the virus was identified, the researchers looked for it in other people.
Reported symptoms were mostly mild – fever, fatigue, cough, loss of appetite, muscle aches, nausea and headache – although we don’t know how long the patients felt well.
A minority had more serious complications, including pneumonia and impaired liver and kidney function. However, the severity of these abnormalities, the need for hospitalization, and deaths were not reported.
Where did this virus come from?
The researchers also determined whether domestic or wild animals were the source of the virus. While they found a small number of goats and dogs that may have contracted the virus in the past, there was more direct evidence that a large proportion of the wild shrews carried the virus.
This indicates that humans may have contracted the virus from a wild fly.
Does this virus really cause disease?
The researchers used a modern technique known as metagenomic analysis to find this new virus. Researchers sequence all of the genetic material and then isolate “known” sequences (such as human DNA) to look for “unknown” sequences that could represent the new virus.
This raises the question of how scientists can determine whether a particular virus causes disease.
They have traditionally used “Koch guesses” to determine if a particular microorganism causes a disease:
It should be found in sick people, not in healthy people.
– He should be able to isolate him from people who have the disease.
– When administered to a healthy person (or animal), it should cause isolation from the patient.
He should be able to isolate himself from a healthy person after he falls ill.
Researchers acknowledge that this new virus does not yet meet these criteria, and the importance of these criteria in the modern era is being questioned.
However, the researchers say they did not find any other cause of illness in 26 people, and there was evidence that the immune systems of 14 people reacted to the virus, and people who were fine had more viruses.
What can we learn from related viruses?
This new virus appears to be a close relative of two other viruses important to humans: the Nipah virus and the Hendra virus. This family of viruses was the inspiration for the fictional MEV-1 virus in the movie Contagion.
The Hendra virus was first reported in Queensland in 1994 when it killed 14 horses and trainer Vic Rail.
Since then, several outbreaks in horses have been reported in Queensland and northern New South Wales and are generally thought to be caused by “indirect” fox infestation.
A total of seven cases of human infection with Hendra virus (mostly veterinarians working with sick horses) have been reported in Australia, including four deaths.
The Nipah virus is more significant globally, with outbreaks often reported in Bangladesh.
The severity of the infection can range from very mild encephalitis to fatal encephalitis.
The first outbreaks were reported in Malaysia and Singapore in people who had close contact with pigs. However, recent outbreaks are believed to have been caused by food contaminated with the urine or saliva of infected bats.
It is noteworthy that the Nipah virus appears to be transmitted from person to person, mainly through household contact.
Little is known about this new virus, and the currently reported cases are probably the tip of the iceberg. At the moment, there is no indication that the virus can be transmitted from person to person.
More work is needed to determine the severity of the infection, how it spreads, and the extent of its spread in China and the region.
The report was prepared under the direction of Allen Cheng, Professor of Infectious Disease Epidemiology at Monash University.
Source: Science Alert.
