Shamonda virus crosses the species barrier: first documented human infection reported in France

France has reported the world’s first documented human infection with Shamonda virus (SHAV), an orthobunyavirus that emerged widely in European livestock during 2026. The case involved a severely immunocompromised patient treated in Lyon who died in early October. Investigations are continuing, but neurological complications observed before death are considered very probably linked to the infection. French and European authorities stress that no risk to the general population has been identified at this stage.

First human infection after decades of animal circulation

Shamonda virus was first isolated from cattle in Nigeria in 1965 and subsequently detected sporadically in Africa and Asia. Until now, no human infection had ever been documented. French authorities consider vector transmission by a Culicoides biting midge in eastern France the most likely hypothesis, in an area where animal circulation had been documented during spring and summer 2026. The exact exposure route remains under investigation.

ECDC confirms that this remains the only identified human case and notes that it has not yet been established whether SHAV caused the patient’s death or contributed to it in the context of severe underlying disease.

A rapidly expanding European animal infection

SHAV was identified for the first time in European farm animals during summer 2026. ECDC reports detections in Austria, Belgium, France, Germany, Ireland, Italy, Liechtenstein, Luxembourg, the Netherlands, Portugal, Spain, Switzerland and Jersey.

WOAH reports that European outbreaks involve two variants, SHAV-EU1 and SHAV-EU2. Cattle are most frequently affected, but infections have also been recorded in sheep, goats, horses and alpacas. Clinical signs include fever, diarrhoea, reduced milk production, abortions and fetal malformations, with neurological disease reported less frequently, particularly in horses.

There is currently no commercial vaccine, and immunity against Schmallenberg virus appears to provide little cross-protection.

What changes for surveillance

The French case establishes that human SHAV infection is biologically possible, but it does not demonstrate frequent zoonotic transmission or human-to-human spread.

ECDC is now working with EU reference laboratories to strengthen diagnostic capacity and identify any additional potential cases. The specific Culicoides species responsible for human transmission is also unknown. Vector activity is expected to decline as temperatures fall across Europe.

WOAH is meanwhile encouraging veterinary services to strengthen animal surveillance, include SHAV in the differential diagnosis of abortions, congenital malformations and reproductive disorders, and improve viral characterisation.