Earlier this month, news broke that a never-before-seen virus – the Langya henipavirus (LayV) – had infected dozens of people in China. Understandably, this sparked some unpleasant déjà vu for many, but just how concerned should we be?
According to the experts: not very, at least not for now. However, the outbreak should serve as yet another example that zoonotic diseases jumping from animals to humans is likely to be all the more common in years to come.
"There is no particular need to worry about this virus at the moment, although ongoing surveillance is of importance," commented Professor Edward Holmes from the Sydney Infectious Diseases Institute at the University of Sydney.
What do we know so far?
So far, at least 35 people have been infected with LayV in China's Shandong and Henan Provinces since 2019, according to a report in the New England Journal Of Medicine published on August 4.
The majority of the cases were in farmers, although a small number were factory workers. Researchers also discovered evidence of the virus in wild shrews, suggesting this is its natural reservoir.
How severe is the disease?
Not extremely, it seems.
Fever was the most commonly reported symptom, which was experienced by every infected person. Other mild symptoms like tiredness, a cough, vomiting, nausea, and headaches were also widely reported. A small but significant number experienced impaired liver and kidney function, as well as low levels of platelets or white blood cells.
However, it’s unclear how severe these complications were and whether people required hospitalization. Fortunately, it does look like there have been no deaths so far.
How infectious is the virus?
As it stands, there’s no evidence of person-to-person transmission. The researchers carried out contact tracing of nine patients with 15 close contacts and found no evidence of the virus being passed on to other people. However, they said their sample was too small to completely rule out the possibility of human-to-human transmission
Furthermore, 35 infections over three years isn’t a huge number of people, although we should take these statistics with a pinch of salt since the currently reported cases are likely to be the tip of the iceberg.
“It is still early days but there are some reassuring signs, namely that there haven’t been deaths or many serious illnesses from it, that there don’t seem to have been many cases, and that person-to person-transmission hasn’t been found, unlike monkeypox and COVID-19,” added Sanjaya Senanayake, a specialist in infectious diseases and Associate Professor of Medicine at The Australian National University
Have we ever seen anything like this before?
Yes. LayV is a henipavirus, the same genus that contains Hendra virus – a bat-borne virus that infects horses and humans, first identified in Australia – and Nipah virus – another zoonotic virus found in Asia.
The Hendra and Nipah viruses seem to be more dangerous than LayV, at least in terms of fatality rate, but it's too early to know for certain.
The novel virus is also closely related to another henipavirus called Mòjiāng virus, which may have infected six miners, killing three of them, in China’s Mòjiāng Hani Autonomous County back in June 2012.
A sign of what’s to come?
It’s widely noted that humanity's "broken relationship" with nature is creating a perfect storm for future pandemics to break out. Through urbanization, deforestation, and the large-scale conversion of land for agriculture, we are encroaching on the natural environment more than ever, upping the risk of a zoonotic disease jumping to humans.
It looks like LayV is just another reminder that humankind is playing with fire.
“This group of viruses pose a constant and real threat to humans and livestock, and viruses like LayV need to be monitored carefully,” remarked Dr Nick Fountain-Jones, a Research Associate at the University of Tasmania.
“Unfortunately, just because we are still experiencing the SARS-CoV-2 pandemic does not mean another isn't around the corner.”