France Confirms World’s First Human Case of Shamonda Virus

French health authorities have confirmed the world’s first recorded human case of the Shamonda virus in an approximately 60-year-old patient with severe immunodeficiency who died in early October 2026 at a Lyon hospital, though officials emphasize there is currently no general public health risk.

Public health bodies across Europe and international agencies are closely monitoring the situation after the French government formally reported the detection. The patient, who lived in the eastern part of France and was receiving treatment for serious underlying illness at a hospital in Lyon, experienced severe neurological complications prior to their death in early October 2026. According to the European Centre for Disease Prevention and Control (ECDC), the patient’s ongoing treatment for a severe medical condition left them much more vulnerable to infections and related complications compared to the general public. Representatives from the French Ministries of Agriculture and Health stated in a joint announcement that while the virus has circulated in livestock for decades, this marks the first time it has ever been documented in a human being.

How the Shamonda Virus Moves From Livestock to Vectors

Known scientifically as an orthobunyavirus within the Peribunyaviridae family and the Simbu group, the Shamonda virus has long been recognized as a pathogen affecting ruminants. Cattle serve as its primary host, though infections have also been documented in sheep, goats, alpacas, and horses, with the World Health Organization (WHO) noting it primarily affects animals such as cattle, sheep, goats, and horses, and belongs to the family Peribunyaviridae, genus Orthobunyavirus, within the Simbu serogroup, making it closely related to the Schmallenberg virus. The virus is transmitted through biting midges, specifically insects belonging to the genus Culicoides.

The pathogen was first isolated from cattle in Nigeria during the mid-1960s and later appeared in parts of Africa and Asia, including Japan. In late July 2026, genetic testing identified the virus in sick livestock across southern Germany, Switzerland, and eastern France, following the first ever detection of SHAV in European farm animals in summer 2026, with clinical signs reported from June. By the summer of 2026, surveillance data from French veterinary research indicated that the virus had spread to 14 Western European countries, including Austria, Belgium, Ireland, Italy, Liechtenstein, Luxembourg, the Netherlands, Portugal, Slovenia, Spain, and the island of Jersey, with the ECDC also listing Germany, France, Switzerland, Austria, Belgium, Ireland, Italy, Liechtenstein, Luxembourg, the Netherlands, Portugal, Spain, Switzerland, and Jersey among the affected locations where the virus has been detected in farm animals.

In infected animals, the virus causes symptoms such as acute diarrhea, fever, lethargy, and a drastic drop in milk production. Data from nine dairy farms in France showed that milk yields plummeted by up to 75% in affected herds, presenting a notable economic challenge for agricultural producers. However, the World Organisation for Animal Health notes that the virus is not classified as a regulated animal disease under European Union health laws.

Health Authorities Say Virus Poses No Wider Threat

Despite the fatality, international and domestic health authorities have sought to calm public concern. Gregory Emery, head of French public health, described the event as scientifically unprecedented while stressing that it poses no wider threat.

“Clearly, we are dealing with an unprecedented case in both scientific and virological terms, involving a man with a severely compromised immune system,” said Gregory Emery, French public health director. “From a medical and public health perspective, there is no risk to the public and no crisis.”

To assess the situation, the World Health Organization and the European Centre for Disease Prevention and Control have collaborated with French authorities, while the ECDC maintains active communication with the European Commission and the European Food Safety Authority (EFSA)—responsible for EU food safety and animal health—alongside continuing ECDC probes into the infection route and whether the virus contributed to or caused the patient’s death.

Based on current available data and knowledge regarding similar viral outbreaks, this case is considered a single human occurrence and is unlikely to lead to widespread transmission at this time, the, World Health Organization said.

While the ECDC points out that SHAV is normally transmitted among animals via infected midges (Culicoides)—though the exact midge species responsible for this transmission remains undetermined—researchers are still working to identify the precise exposure pathway, with the leading theory pointing to an infected midge bite sustained while the patient was visiting eastern France. French authorities confirmed that neurological complications observed before death were highly likely linked to the viral infection, though clinical, biological, and epidemiological investigations remain ongoing to clarify whether the virus was the direct cause of death or a contributing factor alongside the patient’s severe immunodeficiency from leukemia.

Data Indicates Human Transmission of Shamonda Virus Is Rare

Dr. Montien Kanasawat, Director-General of the Department of Disease Control, stated that “currently, epidemiological data indicates that transmission to humans is very rare. As for the situation in Thailand, there have been no previous reports of Shamonda virus infections. The Department of Disease Control has closely monitored situational data from the WHO, ECDC, and French public health agencies, assessing that there are currently no indications of widespread transmission in Europe or other countries, and no human-to-human transmission has been found.”

Thai health officials, working alongside international networks including the WHO and ECDC, confirmed that there is no evidence of human-to-human transmission.