A new bovine virus detected in dairy farms in eastern France

A new bovine virus is worrying dairy farmers in eastern France. Detected in early August in around ten farms, this pathogen closely related to the Shamonda virus is already circulating in neighboring Germany and Switzerland. Although it currently causes only limited symptoms, its rapid spread across the territory is prompting health authorities to strengthen surveillance.

A virus transmitted by midges, close to Shamonda

According to an information note released in early August by the animal health epidemiological surveillance platform (ESA), the identified pathogen belongs to the family of orthobunyaviruses, very close to the Shamonda virus already known in Asia and Africa. Like bluetongue or Schmallenberg disease, it is transmitted by bites from midges (culicoides), and not from bovine to bovine by simple contact.

The virus was first detected in dairy cows in several eastern departments: Doubs, Jura, Ain, Haute-Savoie and Savoie. Similar cases were reported at the same time in southern Germany and in Switzerland, suggesting cross-border circulation of the midge vector rather than an isolated outbreak.

Subtle symptoms but rapid spread

In affected farms, veterinarians mainly observe a transient acute diarrhea, a short febrile episode, general lethargy of the animal and, in dairy cows, a temporary drop in milk production. These signs remain, in the vast majority of cases, transient and not serious for the animal.

What draws the attention of veterinary services is not the severity of the symptoms, considered low, but the speed at which the syndrome has been spreading from one farm to another since its first detection. This is what justifies enhanced surveillance rather than an emergency measure.

• Transmission by midges (culicoides), no direct contact between cattle
• Initial outbreaks in Doubs, Jura, Ain, Haute-Savoie and Savoie
• Main symptoms: diarrhea, transient fever, decreased milk yield
• Impact considered low at this stage in the affected farms
• Similar cases observed in Germany and Switzerland

What consequences for farmers and consumers?

For farmers, the main documented consequence is economic: a temporary drop in milk collection at affected farms while the animals recover. Local animal health defense groups recommend enhanced clinical monitoring of the herd and prompt reporting of any unusual symptom to the attending veterinarian, in order to refine the mapping of the virus’s progression.

At this stage, health authorities have not issued restrictions on the marketing of milk or meat from the affected farms. The situation is nevertheless being closely monitored, similar to previous orthobunyavirus episodes in Europe in recent years, whose impact remained generally limited once the vector's circulation peak had passed.

Frequently Asked Questions

Is this new bovine virus dangerous to humans?

Orthobunyaviruses of this type affect livestock and are transmitted by midges; no official data available to date report transmission to humans in this outbreak.

How is this virus transmitted between farms?

Transmission occurs via bites from culicoides midges, the same type of vector as for bluetongue, and not by direct contact between animals.

What should farmers do when faced with these symptoms?

It is recommended to monitor your herd (diarrhea, fever, drop in milk production) and to quickly report any unusual sign to a veterinarian or to the local animal health defense group.

Sources

• Ministry of Agriculture — Cases of dairy cow infections by an orthobunyavirus
• La France Agricole — The orthobunyavirus would have little impact on affected farms
• GDS Centre-Val de Loire — Shamonda-like virus, an orthobunyavirus identified in eastern France

To follow practical news related to the rural world, find our articles in the section Agriculture, Livestock, Hunting & Fishing. On monitoring and health prevention issues, the Health & Medicine section also offers useful guidance, as does our Technology & Science section for issues of epidemiological surveillance.

This article was written with the help of artificial intelligence. Editorial policy