EXPLAINER | France confirms dead patient had Shamonda virus: what to know

France has reported the first known human case of Shamonda virus in a patient who died, raising questions about the risks posed by a livestock virus that reached Europe this year, decades after first being detected in Nigeria.

Shamonda is transmitted by biting midges and mainly affects cattle, though infections have also been identified in sheep, goats, horses and alpacas.

It belongs to the same group as Schmallenberg virus, which causes reproductive disorders in livestock.

First detected in cattle in Nigeria in 1965, it has since been found in parts of Africa and Asia.

First identified in Europe in late July, by October 20 cases had been reported in more than a dozen European countries, including in top cattle breeders France, Germany, Spain and Ireland. France said the virus had probably been circulating in the country since the spring.

Symptoms include fever, diarrhoea and reduced milk production.

More serious complications include abortions and severe foetal malformations. Neurological disorders have also been reported in some horses.

The World Organisation for Animal Health (WOAH) says the long-term impact of the European variants is uncertain.

The first documented patient was being treated for a serious illness at a hospital in Lyon and had a severely weakened immune system.

The UN’s World Health Organisation said that based on current information and knowledge of the transmission of closely related viruses, this was an isolated human case and unlikely to lead to wider spread at this time.

French authorities suspect infection occurred through a midge bite in eastern France, where the virus circulated among livestock earlier this year.

They said the patient’s brain complications were very likely linked to Shamonda, though investigations into the infection and death are continuing.

Shamonda is not a disease listed by the WOAH and countries are therefore not required to notify WOAH of cases under its disease-specific reporting obligations.

Nor is it listed under the EU’s Animal Health Law framework, meaning it is not subject to EU disease-specific mandatory surveillance.

Because of this, available data may not provide a complete picture of its spread.