Dutch agriculture minister calls for research into new livestock virus

A new disease prowls European livestock operations.

Schmallenberg virus, named for the town in Germany where it was identified, causes brain and limb deformities in ruminant fetuses. The virus infects the females early in their pregnancies. Cattle owners have also reported diarrhea, fever, and reduced milk production in infected cows. No vaccine is available.

So far the disease has been confirmed on 14 sheep farms in Belgium, 51 sheep farms and one goat farm in the Netherlands, and 20 cattle and six sheep operations in Germany.  Many more operations are reporting livestock showing clinical symptoms. The virus is thought to be spread by midges, but this has not been confirmed yet. Researchers are also unsure whether the disease affects other ruminants such as alpacas and llamas.

The disease broke out in the summer of 2011 in cattle herds in the Netherlands and Germany. Samples were initially tested for Bluetongue, pestiviruses, Rift Valley Fever, Epizootic Hemorrhagic disease, and other diseases. All these diseases were ruled out.  Scientists then analyzed the viral sequences contained in the samples, which revealed that the viruses had a strong relation to orthobunyaviruses.

Orthobunyaviruses are more commonly found in Asia, Africa, and Australia. Some viruses within this group can cause abortions and congenital disorders in animal fetuses, if they infect the animals at an early stage. They are also commonly spread by insects such as mosquitos and midges.

Dr. Henk Bleker, the Dutch minister of Agriculture and Foreign Trade, has implemented mandatory notification of the disease in the Netherlands. France has also instigated mandatory notification.

Bleker has also called for more research into the virus, and four areas of research have been designated. They include diagnostics, vaccine development, epidemiology (how the virus is introduced and spread), and virus characterization.

Genomics research will continue to play a role in identifying and controlling the virus. Scientists can detect virus genomes in samples without having to grow the virus in cell cultures. This is quicker than traditional detection methods.

Virus characterization involves studying the virus genome. Virus characterization can help researchers and government officials identify viruses and understand and control viral outbreaks. It has been used to better understand rabies, foot-and-mouth disease, and Akabane virus, which is part of the orthobunyavirus group. In the human medical field, doctors can use virus characterizations to prescribe effective antivirals and deliver more accurate prognoses to their patients.

To date the disease has not spread beyond continental Europe. As cold weather sets in, producers and government officials hope the weather will kill the midges and slow the disease’s spread. Officials in the United Kingdom are asking livestock producers who import animals from Europe to only select animals from virus-free herds. Producers are also urged to report any limb or brain defects in newborn ruminants, as well as any stillbirths or nervous diseases in newborn ruminants from imported dams.