Langya henipavirus

Langya henipavirus (LayV) is a newly identified species of henipavirus that was first isolated in eastern China in late 2018. Henipavirus is a genus of viruses that naturally occur in small mammals but can affect other species, such as dogs, farm animals, and humans. LayV seems to be primarily found in shrews, although it has also been identified in other animals, including humans. Human-to-human transmission does not seem to be an issue. It seems to only be transmitted only from animal to human.

Symptoms of infection include flu-like and respiratory symptoms, such as a cough. Henipavirus infections, such as LayV, can be fatal; however, no deaths have been reported from any of the identified cases. In addition, many researchers do not feel there is a cause for alarm because since 2018 only thirty-five infections have been identified and none of these cases seems to be related.

Background

Chinese researchers first identified the virus in patients during a study of participants experiencing a fever in three hospitals in the eastern provinces of Henan and Shandong between April 2018 and August 2021. A report of the initial investigations of this virus was published by scientists from China, Singapore, and Austria in an article in the New England Journal of Medicine on August 4, 2002. The first patient to be positively identified with the virus was a fifty-three-year-old Chinese woman. The virus was given the name Langya henipavirus after the town of Langya in the Shandong province, where she was from. Researchers took a throat swab from the woman, and from it were able to sequence the LayV genome. They found that the LayV genome was most closely related to the Mojiang henipavirus, a species of henipavirus found in rats in abandoned mines in the southern Chinese province of Yunnan in 2012. They believe it is the only potential pathogen capable of causing illness in twenty-six of the thirty-five patients.

The thirty-five people infected with Lay were mostly farmers who had contact with animals, but the other individuals who were infected were factory workers. While researchers are still unclear as to the exact mode of viral transmission, no solid evidence exists indicating that LayV can spread from person to person because otherwise.

Researchers tested domestic and farm animals living in or near the villages of the patients infected with LayV antibodies and took tissue and urine samples from twenty-five species of small wild mammals found in the area. While they found antibodies in a small number of the domestic and farm animals—only 2 percent of domestic goats and 5 percent of village dogs—27 percent of the samples they had taken from wild shrews showed LayV viral RNA. This provided evidence that the shrews were a reservoir for the virus and had infected people and other animals. However, while the research showed that shrews were the primary infectious animals of the virus, it did not show how people were becoming infected. Further research still needs to be conducted to show exactly how the virus is being transmitted to humans, either directly or via another intermediary animal host. Human-to-human transmission does not seem to be an issue; the virus seems to be transmitted only from animals to humans.

Symptoms of infection include flu-like and respiratory symptoms, such as a cough. Henipavirus infections, such as LayV, can be fatal, but no deaths have been reported from any identified case. In addition, researchers see no cause for alarm among the public because since 2018, only thirty-five infections have been identified and none of these cases seems to be related to each other.

Overview

Henipaviruses are part of the Paramyxoviridae family of viruses, and the more common varieties of these infections include measles, mumps, and other respiratory diseases. LayV is related to two other henipaviruses, Nipah and Hendra, which are the only henipaviruses known to be transmitted from animals to humans. However, the Hendra virus usually affects horses and humans and was first identified in Australia, and the Nipah virus affects humans and bats and is known to have caused outbreaks in southeast Asia. However, unlike LayV, these henipaviruses have high fatality rates.

It is thought that the virus is carried by shrews, and either infects people directly or through another carrier animal. This classifies it as a zoonotic disease, or zoonosis, meaning that it is of animal origin. Eighty-five percent of patients with LayV reported having contact or exposure to an animal within a month of the appearance of symptoms of the infection. Regular testing of people for zoonotic diseases has been recommended by virologists to identify emerging viruses and better understand the associated risks of infection. In this way, a large outbreak of a disease can be managed.

Patients infected with LayV experience symptoms ranging from a mild cough to severe pneumonia. In addition to respiratory symptoms, patients also were reported to have a fever, fatigue, loss of appetite, muscle aches, nausea, headache, and vomiting. Leukopenia, or a decrease in white blood cells, as well as thrombocytopenia, or a decrease in blood platelet cells, was also noted in a significant number of patients. In addition, some patients reported impaired kidney or liver function because of the infection.

The patients with an identified LayV virus are reported to already have or are expected to recover from the infection. However, since these symptoms occur with many conditions or diseases, it is possible that other unidentified cases of LayV existed prior to 2018 and in other geographic areas. Continued surveillance is necessary to determine the full extent of the emergence of this virus and along with control measures to reduce the spread of LayV.

Bibliography

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Lu, Donna. “Newly Identified Langya Virus Tracked after China Reports Dozens of Cases.” The Guardian, 10 Aug. 2022, amp.theguardian.com/science/2022/aug/10/newly-identified-langya-virus-tracked-after-china-reports-dozens-of-cases. Accessed 18 Aug. 2022.

Mallapaty, Smriti. “New ‘Langya’ Virus Identified in China: What Scientists Know So Far.” Nature, 11 Aug. 2022, www.nature.com/articles/d41586-022-02175-z. Accessed 18 Aug. 2022.

McCarthy Simone. “New Langya Virus Found in China Could be ‘Tip of the Iceberg’ for Undiscovered Pathogens, Researchers Say.” CNN World, 12 Aug. 2022, www.cnn.com/2022/08/12/china/china-new-virus-disease-animal-spillover-intl-hnk/index.html. Accessed 18 Aug. 2022.

Murugesu, Jason Arunn. “Langya Virus: How Serious Is the New Pathogen Discovered in China?” New Scientist, 10 Aug. 2022, www.newscientist.com/article/2333107-langya-virus-how-serious-is-the-new-pathogen-discovered-in-china/. Accessed 18 Aug. 2022.

Zhu, Melissa. “Langya: New Virus Infects 35 People in Eastern China.” BBC News, 10 Aug. 2022, www.bbc.com/news/world-asia-china-62489808. Accessed 18 Aug. 2022.