Langya henipavirus under ECDC monitoring
As part of its epidemic intelligence activities, ECDC is monitoring the occurrence of infections with emerging human pathogens including viruses of the Henipavirus genus.
According to a group of Chinese scientists, the detection of a previously unknown, phylogenetically distinct henipavirus, named Langya henipavirus (LayV), was reported in China. Based on the limited information currently available, the risk for EU citizens visiting or residing in the Shandong and Henan provinces of China, where the virus was reported, is considered very low. Similarly, the risk of infection for EU citizens in Europe is considered very low.
The virus was identified through sentinel surveillance of febrile cases with a history of recent animal exposure in eastern China. Between April 2018 and August 2021, 35 patients with acute LayV infection were detected in the Shandong and Henan provinces of China. The following symptoms/signs were reported: fever, fatigue, cough, anorexia, myalgia, nausea, headache, and vomiting.
The majority (85%) of the cases for which information about occupation is available were farmers.
A serosurvey of domestic animals detected seropositivity in goats (in 2% of the tested sera) and dogs (5% of the tested sera.) Wild rodent and shrew samples were tested for LayV infection. Viral RNA was detected in three rodent and two shrew species, predominantly in Crocidura lasiura shrews.
No epidemiological link was identified between the cases in the study. This would support the hypothesis of sporadic zoonotic transmissions, mainly since a large part of the cases are farmers, hence more likely to be in contact with animals than the general population.
There is no indication of human-to-human transmission; however, the possibility cannot be ruled out. Further research will be required to understand the mode(s) of transmission of LayV.
No deaths among the cases were reported by the authors, which could suggest a relatively low disease severity. The symptoms and signs reported are not specific so we cannot exclude the occurrence of human cases before 2018 and a wider geographical distribution of the virus.
Henipaviruses have a wide host range and, while shrews are suspected to be a natural reservoir by the authors/.Further investigation will be needed to understand the hosts and reservoir species.
Detection of this virus of the Henipavirus genus has not previously been described, therefore, this highlights the continuous risk of the emergence of (new) pathogens. These findings are based on a relatively low number of cases and further investigations and research will be required to better understand the epidemiological and microbiological characteristics of the disease and virus. Surveillance for the emergence of pathogens remains a critical tool for the early response to potential pandemic pathogens.