Shamonda virus: France confirms first known human infection

Key takeaways

• France has confirmed the first documented human infection with Shamonda virus, a livestock virus spread by Culicoides biting midges. The patient, who was treated in Lyon, died in early October.
• French authorities describe it as an exceptional case in a severely immunocompromised person. They say no health risk to the general population has been identified.
• The World Health Organization (WHO) told Reuters it is "an isolated human case" and that wider spread is unlikely at this time.
• The leading hypothesis is a midge bite in eastern France, where the virus circulated among cattle this spring and summer. Investigators have not yet confirmed whether the virus caused the death.
• Since July 2026, Shamonda virus has been found in cattle in more than a dozen European countries. There is no vaccine and no specific treatment for animals.

Shamonda virus: what France confirmed about the first human case

France has confirmed the first known human case of Shamonda virus, a livestock virus spread by biting midges of the genus Culicoides. The patient, who was severely immunocompromised, died in early October in Lyon. The World Health Organization calls it an isolated case.

According to the ministry, the patient was severely immunocompromised and was being treated for a serious illness at the Hospices Civils de Lyon. Euronews reported that the ministry described the brain complications seen in the patient as "very likely linked" to the Shamonda infection. Officials have not yet established whether the virus caused the death or contributed to it. Bullquill is not publishing any further details about the patient.

The ministry's position on public risk is clear: "no health risk to the general population has been identified to date." Its updated page on the outbreak in cattle calls this the first documented human detection of the virus anywhere in the world.

What did the WHO say?

In a statement to Reuters on 22 October, the WHO said: "this is an isolated human case and it is unlikely to lead to wider spread at this time." Reuters reported that the agency based this view on current information and on what is known about closely related viruses. The WHO said it is in contact with French authorities and is monitoring the situation.

The European Centre for Disease Prevention and Control (ECDC) is also involved. Euronews reported that clinical, laboratory and epidemiological investigations are continuing with the WHO and ECDC. According to Euronews, the ECDC says it does not yet know which midge species was involved in this case.

What is Shamonda virus?

Shamonda virus is an orthobunyavirus. It belongs to the Simbu serogroup, which also includes Schmallenberg, Akabane and Aino viruses. These viruses mainly infect ruminants and are spread by insects. Austria's food safety agency AGES describes it as an enveloped RNA virus with a segmented genome.

The virus was first identified in cattle in Nigeria in the mid-1960s. Before 2026 it had been reported only sporadically in parts of Africa and in Japan, according to the French Ministry of Agriculture.

Germany's Friedrich-Loeffler-Institut (FLI) and Switzerland's Institute of Virology and Immunology reported a new Shamonda-like virus in cattle in southern Germany and Switzerland in late July and early August 2026. France reported cases at the same time. AGES says the European virus has since been divided into two variants: SHAV-EU1, found mainly in Central Europe, and SHAV-EU2, found mainly in Northern Europe.

How does it spread?

The main route is the bite of an infected Culicoides midge. These are the same insects that carry bluetongue virus and epizootic haemorrhagic disease. The French ministry says no significant direct spread between animals is known, apart from transmission from a pregnant female to her offspring. There is no evidence of person-to-person spread, and the WHO's assessment points the other way.

What does it do to animals?

Cattle are the main hosts. Belgium's public health institute Sciensano and AGES list the usual signs in adult cattle as fever, lethargy, diarrhoea and a sharp drop in milk yield in dairy cows. These signs are usually short-lived. The bigger concern is infection during pregnancy, which can lead to abortion or to calves and lambs born with brain and limb malformations, as seen with the related Schmallenberg virus. AGES also reports that the virus's genetic material was found in the brains of horses that died with neurological symptoms in Germany and Switzerland.

Where has Shamonda virus been found in Europe?

Reuters reported that by 20 October cases had been recorded in more than a dozen European countries. Euronews puts the total at 12 European countries plus Jersey. The table below lists the main detections described by official agencies and wire reports.

Sources: agriculture.gouv.fr, FLI, AGES and Sciensano pages, and Reuters reporting, accessed 22 October 2026.

Official counts may be incomplete. Shamonda virus is not listed by the World Organisation for Animal Health (WOAH), and it is not covered by the EU Animal Health Law, so countries do not have to report it under disease-specific rules. In Austria, AGES notes that the disease is not notifiable and that farmers must pay for testing themselves.

Why was this case unexpected?

Until now, scientists considered Shamonda and its relatives to be animal viruses. The FLI states that Simbu serogroup viruses are generally not considered zoonotic. AGES describes humans as "presumably not susceptible," while adding that this still had to be confirmed for Shamonda. Sciensano wrote in August that there was no evidence the virus caused disease in people.

The French ministry compares the Lyon case to infections with other orthobunyaviruses such as Oropouche virus. Oropouche infections have sometimes caused neurological effects, especially in people with weakened immune systems. That comparison helps explain why officials stress the patient's immune status: a virus that rarely or never harms healthy people can behave differently in someone whose defences are severely weakened.

Is milk or meat safe?

The French Ministry of Agriculture says there is no scientific data showing that the virus spreads through meat, milk or dairy products. It also notes that products from sick animals are always kept out of the food supply. No vaccine exists for animals, and there is no antiviral treatment. Infected herds do not have to be culled. Vector control, such as removing stagnant water and slurry where midges breed, is the main tool available to farmers.

What is still unknown

• Whether Shamonda virus caused the patient's death, or contributed to it alongside the underlying illness.
• Which midge species transmitted the virus. The ECDC says this is not yet known, according to Euronews.
• Whether other people, particularly those with weakened immune systems in areas where the virus circulates, have had mild or unrecognised infections. Officials have not announced any wider human testing.
• The long-term effect of the European variants on livestock, which WOAH says is uncertain, according to Reuters.

What it means

For the general public, the message from French authorities and the WHO is reassuring. This is one case in a severely immunocompromised patient, with no identified risk to the wider population and no sign of person-to-person spread. Among animals, however, Sciensano noted in August that further spread could not be ruled out while the midges remained active.

For science and public health, the case matters because it shows the virus can infect a human at least in exceptional circumstances. It is likely to prompt closer study of Simbu-group viruses in people, better tracking of midges, and more attention to animal-human links in surveillance, an approach often called One Health. The French investigation already brings together human, animal and environmental health experts. For farmers, the practical picture has not changed: the disease is not regulated, there is no vaccine, and protecting herds from midges remains the main defence.

For more science coverage, see our explainers on how often multiple sclerosis is misdiagnosed, NASA's Thwaites Glacier sea-level projections and the UNEP Emissions Gap 2026 report.

Sources

• French Ministry of Agriculture: Cases of infection in dairy cows by an orthobunyavirus (updated 22 October 2026)
• Reuters: First human case of livestock virus Shamonda unlikely to lead to wider spread, WHO says
• Reuters: Explainer: What is Shamonda virus and what are the risks to humans and animals?
• Al Jazeera: France reports first human Shamonda virus case, says no health risk
• Euronews: France confirms first human case of Shamonda virus, previously found only in animals
• Friedrich-Loeffler-Institut: Shamonda virus
• AGES (Austria): Shamonda virus
• Sciensano (Belgium): Shamonda virus suspected case