Background
With all of the attention given to climate-alarmist claims of vector-borne diseases gradually spreading from their indigenous tropical realms to more temperate regions of the world in response to predicted global warming, most people have not looked upon this potential problem as something about which they need be too concerned at present; and the authors thus report that "with few exceptions, vector-borne diseases have long been considered of minor importance in central and northern Europe." However, they write that "since the advent of bluetongue disease (BTD) in 2006, and the 2007 chikungunya fever outbreak in Italy, this attitude has changed."

What was done
Focusing on BTD -- a non-contagious insect-borne viral disease of ruminants (mainly sheep, but also affecting antelope, buffalo, cattle, deer, dromedaries and goats) caused by the bluetongue virus (BTV) -- Kampen and Werner describe what is known about the outbreak of this serious animal disease in central Europe.

What was learned
The two German researchers report that "BTD was the first 'exotic' disease to arrive," but that "it did not slowly spread northwards but jumped in through a still unknown entry point." It all started, as they describe it, "with about 2000 affected ruminant farming facilities in 2006 in the central western part of Europe," where the BTV-8 virus -- which they say "had never been observed in Europe before," and for which DNA sequencing data suggested sub-Saharan Africa as its most likely point of origin -- "managed to overwinter and spread in all directions in 2007, producing almost 60,000 outbreaks (farms affected) in ten European countries up to early 2008." And now they say that the BTV-1 virus strain "appears to be approaching from the south, with some 4900 outbreaks in France in 2008," reiterating that "nobody had expected a novel and independent virus introduction into central Europe together with indigenous biting midges able to transmit BTV." As for possible routes of introduction of the virus, they mention BTV-positive ruminants imported either legally or illegally, virus-carrying midges transported by wind over hundreds of kilometers, accidental importation by ship or aircraft, contaminated vaccines and trade with the products of infected animals.

What it means
In light of all that has been learned about the subject, Kampen and Werner conclude that "it is due to continuing globalization rather than to climate change that even central and northern Europe are at risk of new pathogens as well as vectors of disease entering and establishing." And what is true of Europe is true of extra-tropical lands everywhere.