The story so far:
France reported the first known human infection with Shamonda virus on October 22, 2026. The patient, who was severely immunocompromised and receiving treatment for a serious illness at the Hospices Civils de Lyon, died in early October. Investigations are underway to determine whether the virus caused or contributed to the death, and how the patient acquired the infection.
French authorities suspect that the patient was infected by the bite of a Culicoides midge in eastern France, where the virus had been circulating among animals during spring and summer. The specific insect responsible has not been identified. According to the European Centre for Disease Prevention and Control (ECDC), the virus has been detected in farm animals in Austria, Belgium, France, Germany, Ireland, Italy, Liechtenstein, Luxembourg, the Netherlands, Portugal, Spain and Switzerland, as well as Jersey.
French authorities say that no public health risk to the general population has been identified based on current knowledge of the virus. The World Health Organization (WHO) has also said that wider spread is unlikely based on the information currently available. However, investigations into the human case are continuing.
What is Shamonda virus?
Shamonda virus is a vector-borne virus belonging to the genus Orthobunyavirus in the family Peribunyaviridae. It is part of the Simbu group of viruses, which also includes Schmallenberg virus and Akabane virus.
The virus was first isolated from cattle in Nigeria in the mid-1960s and has since been reported sporadically in cattle in parts of Africa and Japan. Before the recent case in France, it was considered an animal pathogen that did not infect humans.
Cattle are considered its main animal hosts, although infections have also been detected in sheep, goats, horses and alpacas. In livestock, infection can cause fever, diarrhoea, lethargy, loss of appetite and reduced milk production. In pregnant animals, it has been associated with abortions and congenital abnormalities in offspring.
Neurological signs have also been reported in horses infected with the virus in Europe. The extent to which the variants circulating in Europe differ in their effects on animal health remains under investigation.
How does it spread?
The virus is understood to spread primarily through the bites of infected Culicoides midges, tiny blood-feeding insects. The precise midge species responsible for transmitting the European variants has not yet been established.
According to the World Organisation for Animal Health (WOAH), there is currently no evidence of horizontal transmission, or spread between animals through direct contact or other routes. Vertical transmission, from a pregnant animal to its offspring, has been reported.
Two genetically distinct variants, designated Shamonda virus Europe 1 (SHAV-EU1) and Shamonda virus Europe 2 (SHAV-EU2), have been identified in Europe in 2026. Research indicates that they may have been introduced separately. Their geographical distribution, effects on livestock and long-term significance remain under investigation.
Why is it in the news?
The detection in a human has raised questions about whether Shamonda virus can cause disease beyond its known animal hosts. French authorities have reported that the brain complications observed in the patient before death were considered very likely to be linked to the infection. However, investigations are continuing to establish whether the virus caused or contributed to the death.
The patient was severely immunocompromised and had an underlying serious illness. It is not yet known whether similar complications would occur in people with different health conditions or whether people without immune suppression could develop symptomatic infection.
The case highlights the importance of the One Health approach, which recognises the links between human, animal and environmental health. Monitoring infections in livestock, investigating unusual human infections and sharing laboratory findings can help identify emerging health risks.
The virus is also affecting livestock production. A study of nine French dairy herds found a 15%–75% decline in bulk milk production during clinical episodes associated with infection. Affected cattle also showed symptoms such as diarrhoea, reduced activity and, less consistently, fever. The findings are from a small number of farms and do not establish the typical impact across all affected herds.
How prevalent is it?
The prevalence of Shamonda virus in humans is unknown. The French case is the first documented human infection, but it does not establish when the virus first began infecting people or whether other infections have gone undetected. There is insufficient data to estimate the number of human infections worldwide.
In animals, the virus has been identified in parts of Africa and Japan. Its detection in European livestock in 2026 has expanded its known geographical distribution. By October 22, the ECDC had reported detections in farm animals across 12 European countries and Jersey.
These reports indicate the geographical spread of detections, not the proportion of animals infected. Differences in veterinary surveillance, laboratory testing and reporting make it difficult to compare the burden between countries.
There are no verified figures establishing the prevalence of Shamonda virus in India so far. However, the absence of reported detections does not establish that the virus is absent from the country.
The virus is not subject to routine official surveillance or control measures under the European Union’s Animal Health Law. This may limit the completeness of information on its distribution and prevalence in livestock.
How is it diagnosed and treated?
In animals, the symptoms of Shamonda virus infection can resemble those of other livestock diseases. Laboratory testing is therefore needed to confirm infection. Molecular tests, including polymerase chain reaction (PCR) assays, can detect the virus’s genetic material, while genetic sequencing can help distinguish between variants.
Evidence on the clinical presentation and management of human infection remains limited. There is currently no established, Shamonda-specific treatment protocol for human infection. Further investigation is needed to determine how the virus affects humans and what clinical management may be appropriate.
According to WOAH, there are no commercially available vaccines against Shamonda virus. No established vaccine is available for preventing human infection.
What is the public health risk?
French authorities have said that no public health risk to the general population has been identified based on current knowledge. The WHO has assessed wider spread as unlikely on the available evidence. These assessments reflect what is currently known and may change as further information becomes available.
Key questions include how the patient acquired the infection, whether the virus contributed to the death, whether other human infections have occurred and whether the virus can spread between people. There is currently no evidence of sustained human-to-human transmission.
Surveillance of livestock, laboratory investigations and coordination between animal and human health authorities will be important in answering these questions.
For now, the available evidence supports continued monitoring and investigation. The first human case is significant because the virus was previously considered unable to infect humans, but it does not establish that Shamonda virus is spreading widely among people or that a human outbreak is under way.