Lyon: What we know about the Shamonda virus, an animal virus detected for the first time in humans

This is a world first. In a press release sent on Wednesday, state services announced the detection in humans of the Shamonda virus, known only - until now - in animals. 20 Minutes takes stock.

What is the Shamonda virus?

Shamonda is an orthobunyavirus transmitted to animals by biting midges. First detected in Nigeria in the mid-1960s, it has been reported sporadically in cattle in West, East and Southern Africa, as well as Japan. In the summer of 2026, it was identified for the first time in Europe, including France, on cattle farms. “Cattle are considered the main hosts,” writes the Ain prefecture. Sporadic cases were also noted this summer in France in small ruminants and horses. »

How did he infect a human being?

Despite several decades of circulation in Africa and Asia, no human cases had been documented. The Shamonda virus was until now considered non-transmissible to humans. “Infection with the Shamonda virus in this patient thus constitutes the first documented and reported detection of the virus in humans,” recalls the prefecture.

The preferred hypothesis is that of contamination by the bite of a midge of the Culicoides genus, in eastern France, where circulation of the virus in animals was reported in the spring and summer of 2026.

What happened to the affected patient?

In their press release, the health authorities specify that this virus was detected in a severely immunocompromised patient, treated at the Hospices Civils de Lyon (HCL) for a serious pathology. He died in early October.

According to the first elements of the investigation, the cerebral complications observed in the patient before his death would most likely be linked to infection by this virus. This is, the authorities emphasize, an exceptional case, occurring in a severely immunocompromised person.

Clinical, biological and epidemiological investigations are still underway, in a “One Health” approach which brings together experts in human, animal and environmental health. In view of the available knowledge, the authorities indicate that “no health risk for the general population has been identified to date”.

“French health authorities have notified the World Health Organization (WHO) and the European Center for Disease Prevention and Control (ECDC),” the press release concludes.