French health authorities have reported the first documented human infection with the Shamonda virus, an infection previously identified in animals, after a severely immunocompromised patient died following the infection.
The case was announced on Thursday, October 22, 2026, prompting investigations by health authorities and the World Health Organisation (WHO) into how the patient contracted the virus and its potential implications for public health.
According to the French authorities, the patient had been receiving treatment for a serious illness at the Hospices Civils de Lyon and died in early October.
The European Centre for Disease Prevention and Control said investigations were ongoing to establish how the infection occurred and whether the virus caused or contributed to the patient’s death.
“Investigations into whether the virus caused or contributed to the patient’s death and how the infection was acquired are ongoing,” the ECDC said.
Despite the development, French authorities said no health risk to the general population had been identified based on current knowledge of the virus.
The WHO is also monitoring the situation and working with French authorities to establish the source of infection, possible transmission routes and any potential public health risks.
WHO Director-General Tedros Adhanom Ghebreyesus said the patient had a weakened immune system, making them more vulnerable to infection and severe disease.
“The patient was immunocompromised, which made them more vulnerable to infection and severe disease, and unfortunately died. My heartfelt condolences to their loved ones,” he said.
Tedros explained that the patient lived in an area where the virus was circulating among animals and where Culicoides midges, small biting insects, were present.
He added that further investigations were necessary to understand how the infection occurred and determine whether other transmission routes were possible.
“WHO is in contact with French authorities who are collecting information to better understand the source of infection in the first human patient, possible routes of transmission and any potential risk to public health,” the WHO chief said.
WHAT IS THE SHAMONDA VIRUS?
The Shamonda virus belongs to the Orthobunyavirus group and has primarily been associated with infections in animals, particularly cattle. Other animals, including sheep, goats and horses, can also be affected.
The virus was first identified in Nigeria in the mid-1960s and has subsequently been reported sporadically in animals across parts of Africa and Japan.
Until the French case was documented, the virus was not known to infect humans.
French authorities said the leading hypothesis was that the patient acquired the infection through the bite of a Culicoides midge in eastern France, where the virus had circulated among animals during the spring and summer of 2026.
However, the precise route of transmission remains under investigation.
HOW DOES IT SPREAD?
The virus is believed to spread among animals through the bites of infected Culicoides midges.
According to health authorities, the specific insect species responsible for the suspected human infection has not yet been established.
The WHO has stressed the need for further research to clarify the transmission process and determine whether the case has any wider public health implications.
WHERE HAS IT BEEN DETECTED?
The virus has previously been identified in animals in Nigeria and other African countries, as well as Japan.
In 2026, it was detected in livestock in Europe, with infections reported in several countries, including France, Germany, Switzerland, Austria and Belgium.
The emergence of the first documented human infection has prompted European health authorities to strengthen investigations and assess the implications for human and animal health.
SHOULD THE PUBLIC BE WORRIED?
French health authorities have described the case as exceptional because the patient had severe immune deficiency.
The ECDC said the infection occurred in a person whose underlying medical condition increased their susceptibility to infection and complications.
The WHO has also indicated that, based on available information and knowledge of related viruses, the case is isolated and unlikely to lead to wider spread at this time.
Nevertheless, health authorities are continuing to monitor developments while investigations seek to establish how the patient became infected.
The French authorities have notified the WHO and the ECDC, with further findings expected as clinical, laboratory and epidemiological investigations progress.
