The threat from zoonotic diseases

• A new zoonotic virus that has evolved to infect humans was identified in China in August. The New England Journal of Medicine (NEJM) described the virus called Langya (LayV), reported in patients in Eastern China.

Nature of Langya

• The pathogen belongs to the henipavirus family, closely associated with Nipah and Hendra viruses, and was noticed to cause fever and respiratory symptoms among 35 people in China since 2018.
• It was discovered during routine sentinel surveillance of patients who had a fever and reported a recent history of exposure to animals in eastern China.
• It was identified as a phylogenetically distinct henipavirus, indicating its evolution, after being identified in a throat swab sample from a patient.
• The virus was named after the town this patient lived in — Langya in the Shandong province in China.

What are the symptoms?

• Fever, fatigue, cough, anorexia, myalgia, nausea, headache, and vomiting, accompanied by thrombocytopenia or low platelet count, and leukopenia or a low white blood cell count.
• In some cases, impaired liver and kidney functions.

What are the animal origins of LayV?

• To determine the source or animal origin of the infection, scientists drew blood from farm animals and small animals.
• These serosurveys in animals revealed that shrews, a rat-like rodent, might be a reservoir of the LayV.
• Contact tracing of nine patients with 15 close-contact family members revealed no close-contact LayV transmission but acknowledges that the sample size was too small to effectively determine the status of human-to-human transmission for LayV.

Is there cause for worry in the future?

• There is no particular need to worry about this, but constant surveillance would be critical.
• In general, regularly testing humans and animals for emerging viruses is critical to understand the risk of zoonotic diseases.
• The need for surveillance cannot be overstated, certainly not since the COVID-19 pandemic upended the world without warning.