Langya henipa virus detected in China: how dangerous is the new virus?

Updated on 08/11/2022 02:21 PM

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• A new virus has been discovered in China: in the provinces of Shangdong and Henan, 35 people have contracted the Langya virus, a type of henipavirus that has been detected for the first time.
• The report is reminiscent of the beginnings of the corona pandemic. In fact, there are similarities with the corona virus, but also one crucial difference: it is probably not transmissible from person to person.
• An overview of what is known so far about the Langya henipa virus.

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What is Langya henipavirus?

Langya virus (LayV) or Langya henipavirus is a new virus that has now been described for the first time in China. The new virus is assigned to the henipavirus genus, which has infected humans and animals in the Asia-Pacific region in the past. As a research team from China, Singapore and Australia now in the journal “New England Journal of Medicine” reported, 35 cases of the new pathogen were documented between the end of 2018 and the beginning of 2021. Only this pathogen was detected in 26 of the 35 patients. The researchers therefore assume that the Langya henipa virus is the cause of the disease symptoms.

So far, five types of henipavirus have been known. The two eponymous representatives of the genus, the Hendra and the Nipahvirus, were first described in the 1990s. Loud during hendravirus infections in humans RKI are very rare with only ten cases (all in Australia), a large outbreak of Nipahvirus disease was detected in 1999 with over 200 infected people in Malaysia and Singapore, and later also in India and Bangladesh. The newly discovered virus species has the greatest genetic similarity to the Mojiang henipavirus, which was registered in southern China in 2012. At that time, three mine workers died from pneumonia caused by the virus. The workers got infected from rats in the mine.

How is henipavirus transmitted?

Like the corona virus, the Langya henipavirus probably comes from the animal kingdom. It is a so-called zoonosis, the virus is transmitted from animals to humans. In the case of the novel Langya virus, shrews are suspected to be the original host: According to the scientists, the new pathogen was found in 27 percent of the shrews examined in the affected provinces. Hendra and Nipahvirus primarily serve as host animals for flying foxes of the genus Pteropus, which are native to Southeast Asia, Australia and Madagascar.

It is known from the related henipaviruses that the pathogens are transmitted via droplet infection or inhalation of aerosols containing urine. Humans become infected primarily through contact with intermediate hosts, mostly farm animals such as horses (Hendravirus) or pigs (Nipahvirus). How the virus spreads from the original host to the livestock has not yet been fully clarified. Fruits contaminated with the saliva or urine of infected fruit bats also pose a high risk of infection for humans.

In the current case in China, scientists assume that the virus found its way to humans from shrews, dogs and goats as intermediate hosts. Farmers who have close contact with animals are particularly affected by the infection. The international team of researchers, on the other hand, considers infection from person to person to be unlikely. There was no close contact among the 35 registered cases, and contact tracing of the infected did not provide any evidence of human-to-human transmission. However, the researchers cannot finally rule out this transmission path at this point in time, as they emphasize. The number of cases is still too small for that. In the case of the related Nipah virus, human-to-human transmission has already been proven.

What are the symptoms of a henipavirus infection?

Patients who have been diagnosed with Langya henipavirus infection mainly suffer from fever, fatigue, cough, muscle pain and loss of appetite. Headaches, nausea and vomiting are reported in around a third of patients, and in some cases there are also indications of liver and kidney damage. Other henipavirus species can also cause febrile respiratory infections in humans. The Nipah virus can also cause meningitis, which is often fatal.

What is the fatality rate for infection with henipaviruses?

The 35 patients infected with Langya henipaviruses have not yet had any very severe or even fatal courses, as the scientists write in the “New England Journal of Medicine”. There is no reason to panic, but there is a reason for increased vigilance. According to studies, the pathogen can cause potentially fatal diseases. Infections with the Nipah and Hendra viruses are assumed to have a high mortality rate. According to the RKI, more than every second person affected died in the outbreaks observed in Australia and in South and Southeast Asia in the 1990s. How high the mortality rate is, however, also depends heavily on the medical care in the infection area.

How is henipavirus infection treated? Is there a vaccine?

There are no vaccines for humans against the different types of henipavirus, nor are there any specific medications. The WHO recommends intensive, supportive treatment for severe respiratory and neurological courses. A Hendravirus vaccine for horses has been available since 2012, which also limits further transmission to humans. the WHO has identified Nipahvirus as a priority disease for research and development.

Sources used:

• Nejm.org: A Zoonotic Henipavirus in Febrile Patients in China
• RKI.de: Nipah and Hendra viruses at a glance
• WHO.int: Nipah virus