French health authorities said a patient treated for Shamonda virus at Hospices Civils de Lyon has died, in the first known human case. They said they saw no risk to the general population at this stage and notified the World Health Organization and the European Centre for Disease Prevention and Control.
The Ministry of Agriculture described the death as an exceptional case involving a severely immunocompromised patient. The leading hypothesis is that the patient may have been bitten by a Culicoides midge in eastern France, where the virus had been circulating among animals during spring and summer 2026. Authorities said investigations already carried out indicated that cerebral complications observed before the patient’s death were very likely linked to Shamonda infection. Clinical, biological and epidemiological investigations are continuing with expertise in human, animal and environmental health.
Officials said that despite decades of circulation in Africa and Asia, no human cases had been documented until now. Shamonda virus is an insect-borne Orthobunyavirus that primarily affects livestock, particularly cattle, and is transmitted by biting midges. It was first detected in Nigeria in the mid-1960s and has since been reported sporadically in cattle across West, East and Southern Africa, as well as in Japan.
This summer was the first time the virus was detected in Europe, including on cattle farms in France. Cases were also reported in southern Germany, Switzerland and the Netherlands. In August, the UK Animal and Plant Health Agency said cattle in Jersey showed clinical signs consistent with those reported elsewhere in Europe and tested positive. The agency said this confirmed the virus is present in the British Isles and close to Great Britain, highlighting the potential for further spread across north-west Europe.
Cattle are considered the primary host, although sporadic infections in small ruminants and equines were also reported in France during the same period. In infected adult cattle, the main symptoms are fever, loss of appetite, watery or loose diarrhea and abdominal discomfort. Infected dairy cows typically see a sharp drop in milk production.