France reports first human Shamonda virus case

France has reported the first-ever documented human infection with Shamonda virus in a severely immunocompromised patient who later died in early October 2026.

About Shamonda Virus

• Shamonda virus belongs to the Orthobunyavirus genus, family Peribunyaviridae, Simbu serogroup.
• It is closely related to Schmallenberg virus, another insect-borne virus affecting livestock.
• It was first isolated from cattle in Nigeria in 1965 and was later detected in parts of Africa and Japan.
• In 2026, it was detected in Europe for the first time, including France.

Transmission

• The virus is mainly transmitted among animals through bites of Culicoides biting midges.
• Cattle are considered the main hosts, although infections have also been identified in sheep, goats, horses and alpacas.
• In the French human case, the leading hypothesis is transmission through an infected midge bite, though investigations are continuing.

Symptoms in Animals

• Common symptoms include fever, diarrhoea and reduced milk production.
• Infection during pregnancy may cause abortions and congenital/foetal malformations.
• Neurological illness has been reported in some infected horses.

Human Infection

• Before 2026, Shamonda virus had not been documented as causing human infection.
• The first case occurred in a patient with severe immunosuppression, making it an exceptional event.
• Knowledge about symptoms and disease severity in humans remains very limited because only one case has been reported.

Treatment and Vaccine

• There is currently no specific antiviral treatment or vaccine for Shamonda virus.
• Prevention mainly depends on reducing exposure to biting midges and strengthening animal and human surveillance.

One Health Significance

• France is investigating the case through a One Health approach, integrating human, animal and environmental surveillance.
• Authorities are sequencing viral samples and comparing human and animal strains to better understand transmission and public-health risk.