WHO reports first human Shamonda virus case in France

France has reported the first known human case of Shamonda virus, the World Health Organization said on 2 November 2026. The patient died on 8 October after severe brain inflammation.

WHO says the risk to people remains unclear. The virus has also been found in animals in Spain and other European countries.

France notified WHO of the case on 20 October. The patient was an older man from eastern France whose immune system was weak. He had not travelled in the previous year.

He fell ill on 23 September and was found to have severe encephalitis, which means swelling in the brain. Tests on tissue taken after his death confirmed the virus, WHO said. Other causes of the illness had been ruled out.

The source of the infection and how it reached him are still unknown. WHO says spread through biting insects is a possible explanation. Spread through food is also being studied.

The virus was known mainly for infecting animals. WHO says this single human case does not give enough evidence to judge the wider risk.

Shamonda was first found in Europe in summer 2026. By 21 October, detections in animals had been reported in Spain, Ireland, Portugal and several other European countries, WHO said.

In mainland France, the virus had been found in animals across 54 departments by 20 October, mostly in cattle.

WHO says biting midges appear to be the main means of spread among animals. There is no evidence yet that these insects passed the virus to the patient.

There is no vaccine or antiviral drug made to treat Shamonda, WHO said. It called for closer checks on human and animal health and further study of suspected human cases.