France confirms first known human case of Shamonda virus

French authorities have confirmed the first known human infection with Shamonda virus after detecting it in a severely immunocompromised patient who died at a Lyon hospital in early October.

The patient had been hospitalized with a serious underlying illness. The European Centre for Disease Prevention and Control said investigations are continuing into whether the virus caused or contributed to the death and how the infection was acquired.

France’s health and agriculture ministries said the leading hypothesis is that the patient was infected through the bite of a Culicoides midge in eastern France, where Shamonda virus circulated among animals during the spring and summer of 2026. Authorities said no risk to the general population had been identified. The World Health Organization also described the infection as an isolated case that was unlikely to lead to wider spread based on current information and knowledge of related viruses. No sustained human-to-human transmission has been reported.

Shamonda is an insect-borne orthobunyavirus that primarily affects livestock, especially cattle, and has also been detected in sheep, goats, horses and alpacas. First identified in Nigeria in the mid-1960s, it had circulated in Africa and Asia for decades without a recognized human infection.

The virus was confirmed in Europe for the first time in July following tests on sick cattle in Germany, Switzerland and eastern France. It has since been detected in livestock across several other European countries. French authorities said clinical, biological and epidemiological investigations are continuing.