France has reported the first-ever human case of the Shamonda virus (SHAV), which is typically found in livestock, after a patient in their 60s with a weakened immune system died in hospital.

The French government suspects a midge carrying the virus caused the infection, months after the Shamonda virus was first detected in farm animals across Europe, including France, Germany, Spain, Ireland, Italy, Belgium, Austria and the Netherlands.

The man was admitted to a Lyon hospital with an unrelated serious disease and died earlier this month, the European Centre for Disease Prevention and Control reported.

“We are clearly dealing with a case that is unprecedented from a scientific and virological point of view. It is linked to this man’s severely weakened immune system. From a medical and public health point of view, there is no alert and no crisis,” Gregory Emery, head of France’s health directorate, said.

As Europe and the international community scramble to unravel the circumstances surrounding the first human case of Shamonda, which was first detected in Nigeria over six decades ago, here are seven things to know about the virus.

What is Shamonda virus and how is it transmitted?

According to the World Organisation for Animal Health (WOAH), the Shamonda virus is a vector-borne virus in the genus Orthobunyavirus and the family Peribunyaviridae. It belongs to the Simbu serogroup, which also includes the Schmallenberg virus. The virus is transmitted by biting midges, which are flying insects, including species in several families of non-mosquito nematoceran Diptera.

When was the Shamonda virus first detected?

The virus was first detected in cattle in Nigeria in 1965 but has since been identified in other countries across Africa and Asia since the 2000s before being reported in Europe in June this year. Shamonda virus affects farm animals such as cattle, sheep, goats and horses.

Why is France’s case significant?

The case is significant because it marks the first confirmed human infection with the Shamonda virus, more than 60 years after the virus was first detected in animals in Nigeria. The ECDPC and the World Health Organisation have started working with the French government to investigate whether the virus caused or contributed to the patient’s death and how the infection was acquired.

What are the symptoms of the Shamonda virus?

The symptoms of the Shamonda virus in humans remain largely unknown as health agencies investigate the case in France. However, the virus is well-documented to cause fever, diarrhoea, and reduced milk production in animals. More serious complications include abortions, fetal malformations and other reproductive disorders. Neurological problems have also been reported in some horses, according to WOAH.

Is a Shamonda virus outbreak possible?

The World Health Organisation, which coordinates responses to international public health issues and emergencies, said there was no immediate risk of a full outbreak, citing evidence available to the organisation.

“Based on current information and knowledge of the transmission of closely related viruses, this is an isolated human case, and it is unlikely to lead to wider spread at this time,” the organisation stated.

How is Shamonda virus diagnosed?

A diagnostic test is required to confirm the infection in animals, as the symptoms may resemble those of other diseases. It is currently unclear if the symptoms are the same in human patients.

Is there a vaccine?

It is reported that there are currently no commercially available vaccines against the Shamonda virus.