Shamonda virus: first human infection recorded in France — what we know about the cattle disease spread by biting midges

What happened

On 22 October 2026 France's health and agriculture ministries issued a joint statement: for the first time anywhere in the world, a human infection with Shamonda virus has been identified. A patient with a severely weakened immune system was being treated in Lyon for a serious illness and died in early October. According to preliminary findings, the neurological complications the patient developed are very likely linked to this virus.

Doctors reported the suspected infection to the health authorities on 7 October, and the virus was found in several of the patient's samples. On 23 October the French public health agency Santé publique France released further details. France has notified the World Health Organization and the European Centre for Disease Prevention and Control. The authorities have not disclosed the patient's age or other details. The investigation is continuing.

How the infection probably happened

Shamonda is not a virus that spreads from person to person or through food. Among animals it is transmitted by biting midges — tiny blood-sucking insects. Experts believe the patient was most likely infected by a midge bite in eastern France, where the virus circulated among animals in spring and summer. No human-to-human transmission has been identified.

According to the authorities, the patient's condition played a key role: because of severe immunodeficiency, the body could not fight off an infection that a healthy person would probably not even have noticed.

What the authorities say

At this stage no risk to public health has been identified. This is an exceptional case in a patient with a severely weakened immune system.

French health and agriculture ministries, joint statement, 22 October 2026

The ministries stress that the virus circulated among animals in Africa and Asia for decades and had never before been detected in a human.

What kind of virus it is

Shamonda virus is an orthobunyavirus and belongs to the same group as Schmallenberg virus. Europeans remember Schmallenberg well: in 2011 it suddenly appeared in Germany and the Netherlands and within two years had spread across Europe, causing birth defects in calves and lambs. It was named after the town of Schmallenberg in North Rhine-Westphalia, where it was first found in cows with fever and a drop in milk yield. In winter 2011–2012 farmers across Europe began to see calves and lambs with twisted limbs and brain malformations — which made clear how dangerous the virus is for pregnant animals.

Shamonda was first isolated from cattle in Nigeria in 1965. Since then it has been found in cows in several African countries and in Asia, including Japan. On 22 October the World Organisation for Animal Health (WOAH) published a review of how the virus affects animals and noted that the full impact of the variants circulating in Europe is not yet clear.

How the virus reached Europe

Shamonda virus was first found in Europe at the end of July 2026, including on cattle farms in France. According to the bulletin of the French national animal health institute, it has now been detected in 14 countries in western Europe — among them Germany, Austria, Switzerland, the Netherlands, Belgium, Italy and Luxembourg. On 23 October the Czech Republic also reported its first case: the virus was found in an aborted foetus on a cattle farm in South Bohemia.

Exactly how the virus reached Europe has not been established. Midges can be carried long distances by the wind, and the viruses they transmit spread together with livestock and insects.

Shamonda virus is not yet on any national list of notifiable diseases or on the EU list. So when it is detected no emergency measures such as culling or quarantine zones are imposed, and it does not affect veterinary certificates for exporting animals. Countries are limiting themselves to surveillance: the Czech Republic, for example, has since 1 October been testing aborted foetuses, malformed calves, stillborn and weak calves for the virus at the state's expense.

How dangerous the virus is for animals

The virus's main hosts are cattle. According to WOAH, horses, alpacas, sheep and goats can also be infected.

• Cattle. Acute diarrhoea, fever, lethargy and a sharp fall in milk yield. In a study of nine dairy farms in France, milk yield in infected herds fell by up to 75%. In pregnant cows the virus can cause abortions and birth defects in calves.
• Horses. The Czech veterinary service describes brain inflammation and neurological disorders in horses. In summer isolated infections were found in horses and small ruminants in France.
• Sheep, goats and alpacas are also susceptible, but there is little data yet on how the disease progresses in them.

There is no commercial vaccine against Shamonda virus.

What biting midges are

Culicoides midges are very small insects, 1–3 millimetres long — smaller than a mosquito. They are active at dusk and dawn in warm, still weather and breed in damp soil, manure and near water. Midges transmit several important animal diseases — for example bluetongue and Schmallenberg virus. In western Europe they are active from spring until late autumn; in cold winter weather their activity almost stops. The wind can carry midges tens and even hundreds of kilometres — that is how bluetongue spread across seas and borders in previous years.

Should people be worried?

For most people, according to the authorities, there is no risk. There is no evidence that the virus passes from person to person, through food or through contact with animals. Meat and milk from farms where the virus was found are safe: the disease is transmitted only by midges.

People with severely weakened immunity should be more careful — for example after a transplant, during chemotherapy or while taking immunosuppressive drugs. It is worth discussing protection from insect bites with their doctor, especially if they live in the countryside near farms.

For scientists the case is not entirely unexpected. The same group of viruses includes Oropouche virus, which is also spread by midges: in South and Central America it has long caused fever with headache and muscle pain in people, there was a large outbreak there in 2024, and several cases were brought to Europe by travellers. So French experts are studying carefully whether Shamonda can infect people more often than was thought.

How to protect yourself from midge bites

• Use skin repellents, especially in the evening and early morning.
• At dusk, wear long sleeves and trousers if you are near farms, pastures or water.
• Ordinary mosquito nets do not stop midges — you need a net with a finer mesh.
• Midges fly poorly in wind, so a fan helps indoors.

What horse and cattle owners should do

• Discuss with your vet which repellents and insecticides are approved for your animals.
• During the midge season it helps to bring horses into the stable at dusk and dawn and to use rugs and fly masks.
• Remove manure and avoid standing water near stables and paddocks.
• Plan insemination so that the vulnerable period of pregnancy — roughly weeks 8 to 14 — does not coincide with the midge season.
• Call the vet if animals have a fever, a drop in milk yield, abortions or neurological signs: only testing will show whether it is Shamonda, bluetongue or another disease.

And dogs and cats?

There is no evidence that Shamonda virus causes illness in dogs and cats. Midges bite pets too, but for them the main protection against insects is the usual flea, tick and mosquito treatments chosen by a vet. Dog and cat owners do not need to take any special measures at the moment. If you live near a farm where the virus was found, walk your dog as usual; it is only sensible not to linger at dusk by manure heaps, wet pastures and standing water, where midges are most numerous.

What happens next

The French authorities are continuing their investigation and surveillance of the virus in animals. Scientists are studying how dangerous the European variants are for livestock and how firmly the virus has become established in the environment. As the weather turns cold midge activity drops, but the virus may return in spring — as happened with bluetongue and Schmallenberg. If you keep cattle, sheep, goats or horses, follow announcements from your country's veterinary service. Report every abortion to your vet, as well as any calves, lambs or kids with birth defects born in winter and spring: it was exactly such cases that showed in 2012 how widely Schmallenberg had spread.