What is Shamonda virus? First human infection reported as virus spreads among European livestock

The midge-borne virus has been detected in livestock across Europe, including Ireland, but experts say there is no evidence of sustained human transmission

Shamonda virus was detected in a patient who died in early October, French authorities have said. Picture: iStock

A virus detected in a human for the first time in France is unlikely to spread between people, experts have said.

Shamonda virus (Shav) has also been detected in cattle on two farms in Co Cork, in what agriculture minister Martin Heydon confirmed was the first detection of the virus in Ireland.

The virus is spread by biting midges and primarily affects livestock, including cattle, sheep and goats. In infected cattle, symptoms can include fever, diarrhoea and reduced milk production, while infection in pregnant animals can lead to abortions or foetal malformations.

Shamonda virus was detected in a patient who died in early October, French authorities have said.

They said the patient was already “severely immunocompromised” and that there was currently no risk to the wider public.

The virus had previously been considered unable to infect humans.

The European Centre for Disease Prevention and Control (ECDC) said it was “carefully monitoring the situation”.

It said: “ECDC is in contact with the French authorities and European partners to investigate the potential, public health implications of this first human infection.

“The only infection so far has been in a patient receiving treatment for a serious illness that made them more susceptible to infection and complications than the general population.

“The patient died in early October. Investigations into whether the virus caused or contributed to the patient’s death and how the infection was acquired are ongoing.”

Virus detected in livestock across Europe

Shamonda virus has been found in European farm animals since the summer. Clinical signs of infection in animals were reported from June, and the virus was identified in late July.

The ECDC said it had since been detected in farm animals in Austria, Belgium, France, Germany, Ireland, Italy, Liechtenstein, Luxembourg, the Netherlands, Portugal, Spain and Switzerland, as well as Jersey.

“In Europe, biting midges are generally most active from spring to autumn, with seasonal patterns varying by species, location and weather,” it said.

“Given the cooling temperatures, the activity of most biting midge species is declining in Europe.”

Experts say risk to public is low

Dr Ben Brennan, group leader and senior lecturer at the MRC-University of Glasgow Centre for Virus Research, said: “This is an important scientific finding, as it is the first reported human infection with Shamonda virus.

“However, it is important to put this into perspective. The patient had a serious underlying illness that left them particularly vulnerable to infections, and we do not yet know whether Shamonda virus contributed to their death.

“Finding a virus in a severely immunocompromised patient does not necessarily mean it poses a significant risk to otherwise healthy individuals.

“At present, there is no evidence that Shamonda virus causes widespread human disease, although further investigation is needed to understand its ability to infect people….

“Based on the information currently available, there is no reason for the general UK public to be unduly concerned.

“There is currently no evidence of sustained transmission between humans, and the virus is normally spread through biting midges rather than everyday contact between people.

“While this discovery warrants further scientific investigation and continued surveillance, it does not currently suggest a significant new public health threat to the UK.

“For most people, there is no reason to change their normal activities or take additional precautions.” 

Paul Hunter, professor of medicine at the University of East Anglia (UEA), said the disease “is primarily a problem in less economically developed countries” and that “we cannot say for certain that no human cases have previously occurred”.

He said severely immunocompromised people could be susceptible to infections that would not cause problems in others.

“So, at present we can assume that the risk of onward person-to-person transmission is tiny. But tiny is not zero.

“One of the issues with infections in people who are immunocompromised is that they may not clear the infection.

“There is, therefore, the risk that the virus could evolve over time in such a patient to become more transmissible to humans. The fact that this case has died reduces that possibility.

“The risk that this virus goes on to cause more widespread problems is very small, but if I was involved in the investigation, I would want to check contacts to make sure no one else has picked it up.”