France detects first human case of Shamonda virus
A severely immunocompromised patient died in Lyon; French authorities rule out risk to the general population and the investigation remains open.
France reported Thursday the first documented human infection with Shamonda virus, which until now had only been detected in animals, according to a joint statement from its agriculture and health ministries. The patient was severely immunocompromised, was being treated at the Hospices Civils de Lyon for another illness and died in early October.
French authorities consider it "very likely" that the brain complications that preceded the death stem from the virus. The ECDC, the European disease surveillance agency, adds a caveat: it is investigating whether the virus caused the death or only contributed to it.
The ministries say they see "no health risk for the general population" so far. Benjamin Brennan of the MRC Centre for Virus Research at the University of Glasgow says there is no evidence of sustained person-to-person transmission. José Francisco Ruiz Fons, a scientist at Spain's CSIC, cautions that there is still no clear evidence the virus caused the illness and expects more data, such as the full genome.
The virus, an orthobunyavirus, was first described in Nigeria in the sixties and was known in cattle in Africa and Asia. It appeared in Europe for the first time in the summer of 2026, on cattle farms, and the ECDC has recorded it in a dozen countries, including France, Germany, Italy, Portugal and Spain.
The low risk the authorities describe applies to the general population of Europe. The case does affect a specific group, people with severe immunosuppression, and there is no peer-reviewed study yet.
How the man was infected is unknown. A biting midge of the genus Culicoides is suspected of having bitten him in the east of the country, where the virus circulated among animals in spring and summer, though that route is unconfirmed. The insects' activity drops in the cold, and the ECDC will reinforce its analysis with the European Union's reference laboratory to look for other possible cases.
