A new virus hits European livestock this spring

Wednesday, May 2, 2012

The so-called Schmallenberg virus has made its appearance on hundreds of farms, affecting sheep, cattle and goats. But so far consumers have not given way to panic boycotts of beef, milk and lamb

by NORMAN DUNN

There's nothing so unnerving for livestock farmers as the sudden appearance of a new animal disease. This is what's happening this year in Europe, where poultry farmers are already on red alert after reports of new avian influenza outbreaks in Portugal and Italy, perhaps carried by migratory wild birds as they wing in from the south for summering in northern Europe.

But so far a new virus overshadows almost everything else in farming this spring. The so-called Schmallenberg virus seems to affect cattle, sheep and goats. It causes high fever and diarrhea, along with dramatic loss of milk in dairy animals. But most survive. Much more important is that infected animals at a certain stage of pregnancy – British vets suspect this is between days 30 and 50 with sheep and 60 to 110 for cattle – either abort or give birth later to deformed or dead animals.

Vectors so far identified are biting midges and mosquitoes. The Robert Koch Institute, Germany's main facility for disease monitoring and protection, reckons the virus belongs to a group formerly mainly known only in Africa, Southeast Asia and Australia. Now, the Schmallenberg branch of this virus family is rapidly making itself at home throughout Europe.

In 2011, still-born calves and lambs were reported in the Netherlands and then, just at Christmas, the same problems were reported by vets around the upland town of Schmallenberg in Westphalia.

The first victim was a cow and her calf, followed by one of the few bison to be found in Germany.

It seems that, throughout last summer, the midges and mosquito vectors have been travelling far and wide because in January, February and March of this year, reports of Schmallenberg virus have been pouring in from France, Belgium, Luxembourg, Italy and the United Kingdom. In Germany alone, the disease had been reported on 750 farms by the end of February. In Britain, 74 farms had reported dead lambs or calves due to the disease by that time. But, of course, the lambing and spring calving in Europe hasn't really started at the time of writing, with no officials hazarding a guess as to what the final damage might be.

If there's any good news on this front, it's that for once usually panicky European consumers have not reacted to news of the disease with massive boycotts of beef, milk and lamb. That there's been relatively little reaction can be attributed to two completely different factors.

The most encouraging one is that farming lobbies in Germany and the Netherlands have gone out of their way to explain to the public through the general press that Schmallenberg virus is not known to infect humans, either through the insect vectors or through consumption of meat or milk from animals that may be infected. The renowned Robert Koch Institute is one of the organisations that were quick to reassure the European public on these points. According to veterinary sources in several countries, all casualty animals recognised as infected will also be kept out of the food chain.

And there's another, rather less encouraging reason why the relatively sudden outbreak of this disease has not caused massive drops in purchases of livestock products throughout the continent.

Even more sensational news has been claiming the headlines day after day. The plight of the Costa Concordia, for instance, dominated most of the European media for a month – at least until its sister ship broke down and caught fire in the Indian Ocean. Admittedly, these are tragedies, too, but at least they represent a welcome respite for the meat and milk producers of Europe this spring.

Although the Schmallenberg losses throughout Europe could be high, virologists are already estimating that breeding animals infected this year could well be immune to further infection. This uplifting theory is based on the similarity of the virus to the Akabane virus, first identified in Japan but prevalent nowadays in Australia, the Far East, Middle East and Africa. Blood sucking midges are also vectors of the Akabane virus, which usually heads straight for the placenta of pregnant cattle, sheep and other ruminants, but also horses, and causes death or deformity of the unborn animal. In Australia, for instance, it's been established that infected cattle can be bred successfully and safely in subsequent years.   

But, no matter what happens in the following years, Europe's latest animal disease problem looks like it's causing serious damage on livestock farms this spring and summer. BF

Norman Dunn writes about European agriculture from Germany.