Potent strain of bluetongue virus is spreading in northern Europe, threatening sheep and cattle

A dreaded pathogen is spreading rapidly among livestock in the Netherlands for the first time in 14 years, killing sheep and sickening cattle. Bluetongue virus (BTV), which is endemic in tropical and subtropical regions, is transmitted by biting insects called midges. It does not infect humans, but the new outbreak is especially concerning because Dutch livestock have been stricken with a potent strain for which no vaccine is available in Europe. Within 2 weeks of its first detection in the country, the virus had been confirmed in 18 flocks of sheep and 55 cattle herds. And this week a sheep on a farm across the border in Belgium tested positive. The previous outbreak in 2007 involved a milder strain of the virus, which spread across tens of thousands of European farms and cost an estimated €175 million in the Netherlands alone, much of it from curtailed trade. EU member nations and the United Kingdom have imposed livestock trade restrictions to limit the disease’s spread. Officials in the U.K., which has been free of bluetongue since 2010, are worried infected midges will blow across the North Sea from the Netherlands. They are monitoring winds and modeling potential “plumes” of midges. Bluetongue can kill sheep and sicken dairy cattle enough that milk production drops significantly. Infected animals have fever, blisters, and other symptoms. The disease’s hallmark, a blueish tongue and lips, comes from the destruction of tiny b...
Source: ScienceNOW - Category: Science Source Type: news