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| Explained: What Is Langya Henipavirus? All About The Zoonotic Virus Outbreak Confirmed In China |
A study titled 'A Zoonotic Henipavirus in Febrile Patients in China', published in the New England Journal of Medicine (NEJM), states that the Langya henipavirus or LayV was identified in a throat swab sample from one patient in eastern China. Febrile is an adjective used to describe someone showing symptoms of a fever. The Langya henipavirus was discovered during a surveillance of febrile patients with a recent history of animal exposure in eastern China.
The Hendra Virus and the Nipah virus are part of the genus henipavirus, which belongs to the family Paramyxoviridae. According to the new study, the Hendra Virus and the Nipah virus are known to infect humans and cause fatal disease. However, other related henipaviruses have been detected in bats, rodents, and shrews. Henipaviruses are naturally found in pteropid fruit bats (flying foxes) and microbats of several species.
What Is Langya Henipavirus?
The Langya henipavirus is a "phylogenetically distinct henipavirus" and has a genome organisation identical to that of other henipaviruses, according to the NEJM study.
The genome of Langya henipavirus is composed of 18,402 nucleotides. The virus is phylogenetically related to Mojiang henipavirus, which was discovered in southern China.
As many as six henipavirus species have been identified so far. These are Hendra virus, Nipah virus, Cedar virus, Ghanaian bat virus, Mojiang virus, and Langya henipavirus.
According to the CDC, Hendra virus and Nipah virus are highly virulent, can cause outbreaks in humans, and cause fatal disease. However, the Cedar virus, Ghanaian bat virus, and Mojiang virus are not known to cause human disease.
What Are The Symptoms Of Langya Henipavirus?
The new study identified 35 patients with acute Langya henipavirus infection in the Shandong and Henan provinces of China. Of these, 26 patients were infected with Langya henipavirus only, which means that no other pathogens were present.
According to the study, all the patients were presented with fever. Meanwhile, 54 per cent of the patients experienced fatigue, 50 per cent had cough, 50 per cent experienced anorexia, 46 per cent suffered from myalgia (pain in the muscles), 38 per cent had nausea, 35 per cent had suffered from headache, and 35 per cent experienced vomiting.
Other abnormalities observed in the patients included thrombocytopenia (deficiency of platelets in blood), leukopenia (low level of white blood cells in blood), and impaired liver and kidney function.
Thrombocytopenia, leukopenia, impaired liver function, and impaired kidney function were observed in 35 per cent, 54 per cent, 35 per cent, and eight per cent of the patients, respectively.
Therefore, the study found that the common symptoms associated with Langya henipavirus are fever, fatigue, cough, anorexia, myalgia, nausea, headache, and vomiting.
Langya henipavirus was the only potential pathogen detected in 26 of the 35 patients with acute Langya henipavirus infection.
What Is The Origin Of Langya Henipavirus?
The study authors also conducted a serosurvey of domestic animals. They detected seropositivity in goats and dogs.
Out of 168 goats, three were found to be positive for Langya henipavirus, which means the seropositivity was two per cent for goats. For dogs, seropositivity for Langya henipavirus was five per cent.
A total of 25 wild small animals were surveyed. Of these, Langya henipavirus RNA was predominantly detected in shrews. As many as 262 shrews were surveyed, and of these, 71 were positive for Langya henipavirus, indicating that the seropositivity was 27 per cent.
This is a "finding that suggests that the shrew may be a natural reservoir" of Langya henipavirus, the study states.
Is Human-To-Human Transmission Of Langya Henipavirus Possible?
Human-to-human transmission has been reported for the Nipah virus. The study authors note that their sample size was too small to determine the status of human-to-human transmission for Langya henipavirus.
According to the study, there was no close contact or common exposure history among the patients. This suggests that the infection in the human population may be sporadic.
The authors also note that contact tracing of nine patients with 15 close-contact family members revealed no close-contact Langya henipavirus transmission.
According to the authors further investigation of the newly identified henipavirus is required to better understand associated human illness.
"In our study, a newly identified henipavirus of probable animal origin was associated with febrile illness, a finding that warrants further investigation to better understand associated human illness," the authors conclude in the study.
References:
- Beijing Institute of Microbiology and Epidemiology, Beijing, China.
- Qingdao Municipal Center for Disease Control and Prevention, Qingdao, China.
- Duke-National University of Singapore Medical School, Singapore, Singapore.
- State Key Laboratory of Pathogens and Biosecurity, Beijing, China.
- Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.
- Changchun Institute of Veterinary Medicine, Changchun, China.
- Beijing Institute of Microbiology and Epidemiology, Beijing, China fang_lq@163.com.
- Duke-National University of Singapore Medical School, Singapore, Singapore linfa.wang@duke-nus.edu.sg.
- Beijing Institute of Microbiology and Epidemiology, Beijing, China lwbime@163.com.
