What Is Shamonda Virus? Cause, Symptoms and Vaccine Questions After First Human Case in France Ends in Death

French authorities have confirmed the first documented human case of Shamonda virus, previously known to infect animals. The severely immunocompromised patient died in early October, but it remains unclear whether the virus contributed to the death.

The discovery has raised questions about Shamonda virus symptoms, how the disease spreads and whether a vaccine exists.

French authorities confirmed the case on 22 October, revealing that the patient had a severely weakened immune system and died in early October. However, investigators have yet to establish whether Shamonda virus caused or contributed to the death.

The European Centre for Disease Prevention and Control (ECDC) said no risk to the general population had been identified based on the available evidence.

What Is Shamonda Virus?

Shamonda virus is an insect-borne virus belonging to the genus Orthobunyavirus and the family Peribunyaviridae. It forms part of the Simbu serogroup, which also includes Schmallenberg virus.

First isolated from cattle in Nigeria in 1965, Shamonda virus was subsequently identified in parts of Africa and Asia before reaching Europe in 2026. The virus primarily spreads through bites from infected Culicoides midges, tiny biting flies that can transmit infections between animals.

According to the World Organisation for Animal Health (WOAH), there is currently no evidence of direct animal-to-animal transmission, although transmission from pregnant animals to their offspring has been reported.

The precise circumstances of the first human infection remain unknown.

Shamonda Virus Symptoms in Humans and Animals

The symptoms of Shamonda virus infection in humans remain largely unknown because the French case is the first documented human infection. French authorities reported that the patient developed neurological complications considered very likely to be linked to the infection. However, whether the virus contributed to the patient's death remains under investigation.

In animals, Shamonda virus can cause several symptoms, including fever, diarrhoea and reduced milk production. More serious complications include abortions, reproductive disorders and foetal malformations. Neurological problems have also been reported in some infected horses.

WOAH emphasises that laboratory testing is necessary to confirm infections because these symptoms can resemble those caused by other animal diseases.

Is There a Shamonda Virus Vaccine?

There are currently no commercially available vaccines against Shamonda virus, according to WOAH. The absence of a vaccine comes as scientists continue investigating the virus' potential effects on human health. WOAH is working with the World Health Organization (WHO) and scientific networks to assess potential risks.

However, the first documented human infection does not establish that Shamonda virus poses a widespread threat to people.

Shamonda Virus Spreads Across Europe

Shamonda virus has been detected in farm animals across several European countries, including France, Germany, Belgium, Ireland, Italy, Spain and Switzerland.

Two European variants, designated SHAV-EU1 and SHAV-EU2, have been identified during the 2026 outbreaks. Scientists have yet to determine their long-term impact, particularly on cattle populations previously unexposed to the virus. Outbreaks may follow seasonal patterns associated with midge activity.

How Did the Patient Contract Shamonda Virus?

Investigators suspect the patient contracted Shamonda virus in eastern France, where infected livestock and biting midges were present during spring and summer.

The ECDC is working with French authorities to establish the infection route and assess its possible contribution to the patient's death. European health agencies are also strengthening surveillance and laboratory testing to identify any additional human cases.