An exceptional infection, ministries say

The health and agriculture ministries described the case as an exceptional one, involving a severely immunocompromised patient who had been hospitalised and died earlier this month. According to preliminary findings cited by the ministries, the neurological complications seen in the patient before his death were very likely linked to infection with the Shamonda virus. They stressed that no health risk to the general public had been identified at this time.

A virus that had never infected humans

Despite circulating in Africa and Asia for several decades, the Shamonda virus had never previously been detected in humans, the ministries said. The virus was first detected in Nigeria in the mid-1960s and has since been reported in cattle in parts of Africa and in Japan.

• •The virus, which belongs to the Orthobunyavirus group, was detected in Europe for the first time at the end of July, including on French cattle farms.
• •It has now been found in 14 western European countries, according to a bulletin from France's national animal health research institute.

How the patient is believed to have been infected

Shamonda is transmitted by biting midges and is found mainly in cattle, though it has also been detected in horses, alpaca, sheep and goats, according to WOAH. Cattle are the main hosts, and France recorded sporadic infections in smaller livestock and horses over the summer.

Investigators believe the patient contracted the virus through the bite of a midge in eastern France, where the virus circulated in animals in spring and summer.

Impact on livestock and next steps

In cattle, the main symptoms are acute diarrhoea, fever, lethargy and a drop in milk production. A study of nine French dairy farms found milk output fell by up to 75 percent in affected herds. WOAH said there are currently no commercially available vaccines against the Shamonda virus.

• •Clinical, biological and epidemiological investigations are still ongoing.
• •The World Health Organization and the European Centre for Disease Prevention and Control have been notified.