France reports the first human case of Shamonda virus, resulting in the death of an immunocompromised patient.
Authorities state no public health risk has been identified, as the virus, previously found in livestock, is transmitted by midges.
Investigations are ongoing to understand human transmission and assess potential risks.
A patient in France died in early October after contracting Shamonda virus, in what authorities have described as the first known human case of the infection.
French authorities said no risk to the general public had been identified so far.
The patient, whose identity has not been disclosed, was immunocompromised and had been receiving treatment for a serious illness, making him more vulnerable to infections, according to a joint statement from France's health and agriculture ministries.
Shamonda virus had previously been detected only in animals, mainly livestock, and is thought to be transmitted through the bites of midges, small flying insects.
The virus was first isolated from cattle in Nigeria in 1965 and has since been identified in parts of Africa, Asia and Europe, according to the World Organisation for Animal Health (WOAH).
Most recent reports have involved cattle, although infections have also been recorded in sheep, goats, horses and alpacas.
Reported symptoms in animals include fever, diarrhoea, reduced milk production and reproductive disorders, including miscarriages and foetal malformations. Neurological symptoms have also been reported, although less frequently, WOAH said.
However, the World Health Organization (WHO) said further studies were needed to understand how the virus is transmitted to humans.
According to the WHO, the patient had been in an area where the virus was circulating among animals and where Culicoides midges, which can transmit certain animal viruses, were present.
BBC News reported that the patient contracted the virus in eastern France, where infections in animals were first identified in the spring.
WHO Director-General Tedros Adhanom Ghebreyesus expressed condolences to the patient's family and loved ones.
He said the WHO was in contact with French authorities, who were gathering information to establish how the patient became infected, identify possible routes of transmission and assess any potential risk to public health.
There are currently no commercially available vaccines against Shamonda virus, according to WOAH.