Ninety-four farms in northern France have been hit by a novel virus, first uncovered in Germany last year, that strikes cattle, sheep and goats, a French research agency reported on Tuesday.
The Schmallenberg virus, named after the town in Germany where it first surfaced, causes diarrhoea and falling milk production in cattle and foetal defects in lambs, calves and kids, the Centre for International Cooperation in Agricultural Development Research (Cirad) said.
In addition to France and Germany, cases have also occurred in Belgium, Britain and the Netherlands, it said.
The virus is probably transmitted by midges or mosquitoes and may have spread "widely" last summer before it was detected, Cirad said.
On February 1, the Friedrich Loeffler Federal Research Institute of Animal Health that 186 farms in Germany had been hit, up from 51 five days earlier.
As of January 26, 76 farms in the Netherlands had been affected.
The Paris-based World Organisation for Animal Health (OIE), which monitors cross-border trade in farm animals, said it was closely following events.
The virus is not a "listed disease," the OIE told AFP, referring to diseases that require member-states to notify the agency whenever they detect an outbreak.
However, "countries have been very proactive and transparent in notifying the OIE of the appearance of the Schmallenberg virus on their territories. Disease surveillance and control has proven to work very well," it said.
"The OIE is monitoring the situation very closely and has decided to convene a group of experts this week to review the current knowledge."
Explore further: Organic apple orchards benefit from green compost applications