France has reported the first documented human Shamonda virus infection after an immunocompromised patient died. Authorities are investigating the virus's role while reporting no identified risk to the general population.There is no commercially available vaccine against Shamonda virus.

France has reported the world's first documented human infection with the Shamonda virus, a pathogen previously known to circulate mainly among livestock.The patient, who had a severely weakened immune system and was being treated for a serious illness, died in early October.Health authorities are investigating whether the virus contributed to the death, while stressing that no risk to the general population has been identified so far.The case marks a significant development in understanding a virus that has primarily been associated with animal infections. French authorities suspect the patient was infected in eastern France through the bite of a Culicoides midge, a tiny biting insect that transmits the virus among animals.

WHAT IS THE SHAMONDA VIRUS?Shamonda is an insect-borne virus belonging to the Orthobunyavirus genus and the Simbu serogroup. It was first identified in Nigeria in the 1960s and has previously been reported sporadically in parts of Africa and Japan.The virus primarily affects cattle, although sheep, goats, horses and alpacas can also be infected.

In cattle, symptoms can include fever, diarrhoea, lethargy and a decline in milk production. Some farms affected by the recent European outbreak have reported substantial losses in milk yield.

Infection during pregnancy may also be associated with reproductive complications and foetal abnormalities, although further investigation is needed to establish the impact of the newly detected European strain.WHAT DOES THE NEW CDC STUDY REVEAL?A study published in the US Centres for Disease Control and Prevention's journal Emerging Infectious Diseases documents the emergence of a Shamonda virus clade in Central Europe in 2026.Researchers investigated an outbreak of illness among dairy cattle in southern Germany and Switzerland that began in mid-June. Affected animals showed reduced milk production, diarrhoea, fever and lethargy.

By late July, more than 100 affected farms had been reported in Germany's Baden-Wrttemberg region.Using molecular testing and metagenomic sequencing, scientists identified the virus and recovered its complete genome.Genetic analysis showed that it was closely related to a Shamonda virus previously identified in Nigeria. The researchers found no evidence that the virus originated through reassortment between different viral lineages.The study also found that existing immunity against Schmallenberg virus, another member of the Simbu serogroup, was unlikely to provide meaningful protection against Shamonda.The researchers called for sustained surveillance of livestock, biting insects and potentially susceptible animal species.

Importantly, the study examined infections in animals and did not establish human-to-human transmission.SHOULD PEOPLE BE WORRIED?French authorities have described the human infection as exceptional, involving a severely immunocompromised patient. The European Centre for Disease Prevention and Control is monitoring the situation alongside national authorities.There is currently no evidence establishing sustained transmission among humans, and no general-population health risk has been identified.However, the case highlights the importance of investigating viruses that circulate in animals, particularly when their distribution changes.There is no commercially available vaccine against Shamonda virus.

For now, scientists are working to understand its transmission, its effects on different species and whether the human case signals a previously unrecognised risk.- Ends