The BBC has reported the detection of the Shamonda virus (Shav) in a patient who died in recent weeks.

This would make it the first known case of humans being infected by the virus.

French health officials said it was an “exceptional case in a severely immunocompromised patient” and there was currently no risk to the public.

Shav is a disease that primarily affects cattle and can be spread by infected midges. Cases have also occurred in sheep, goats, alpacas and horses, but infections in people were previously unheard of.

The World Health Organisation (WHO) and European Centre for Disease Prevention and Control (ECDC) said they were monitoring the situation.

French officials are still investigating how the virus had spread to a human.

The BBC said: “It is currently thought the patient contracted Shav through a midge bite in eastern France, the country’s health and agriculture ministries said on Thursday, where cases were first identified in animals in the spring.

“They said the patient was being treated for a serious illness in a Lyon hospital and experienced neurological complications thought to have been “very likely linked” to the virus, based on initial findings.”

The statement emphasised that the patient’s immune system was weakened, leaving them more vulnerable to getting ill.

“Until now, the Shamonda virus was considered non-transmissible to humans,” the statement noted. Previously, it had been identified only in animals “despite decades of circulation of the Shamonda virus in Africa and Asia”.

Dairy herds that catch Shav from bites can experience fever, diarrhoea and poor milk production.

The WHO confirmed this was the first documented human case of the disease.

It has not yet made its own formal risk assessment, but advised that current information and knowledge of similar diseases suggested the case was isolated and “unlikely to lead to wider spread at this time”.

The first cases of the virus in Europe were identified in late July, the agency said. It has since been detected in farm animals in several countries, including Ireland, Germany, Italy and Spain, as well as in Jersey.

A report in Nature said infectious-disease researchers have emphasised that the risk of the livestock pathogen moving between people is low.

The report said the man who died on 9 October, 16 days after he started showing neurological symptoms, was aged in his sixties.

The symptoms included vision loss and confusion, according to a case report published in Eurosurveillance this week. Infectious-disease researchers say little is known about the virus or how it affects the body.

Citing the case report, Nature said the man lived in a rural area in the Rhône–Alpes region, where Shamonda virus has been detected in cattle.

The report says he was probably infected after being bitten by midges, although less likely routes included contracting the virus by eating contaminated food or through a blood transfusion or transplant.

Shamonda virus belongs to a family of viruses called orthobunyaviruses, which are known to infect animals such as cows and deer, and are transmitted by mosquitoes and midges, says Krispin Hajkowicz, an infectious-disease researcher at the University of Queensland, Australia. There are no vaccines or antiviral treatments for orthobunyaviruses, Hajkowicz says.

More orthobunyaviruses are being detected in people, says Daniel Rawle, a virologist at the QIMR Berghofer Medical Research Institute in Brisbane, Australia.

Climate change and greater contact between wildlife, livestock and humans are among the factors that have increased the risk of people becoming infected. Another consideration is the growing number of people who are immunocompromised, making them more at risk of being infected and developing life-threatening symptoms.