Outbreak of bluetongue disease (BTD) in Germany and the danger for Europe

Abstract

In August 2006, the blue tongue virus (BTV-type South Africa serotype 8) was detected for the first time in cattle blood probes in the Netherlands, immediately followed by cases in Belgium and in cattle on German farms, which were situated close to Aachen at the border to those countries. Within less than 2 months the disease spread eastwards crossing the Rhine, southwards to Luxemburg and to Northern France. At the end of the year 2006, nearly 1,000 farms were affected in Germany. Catches on two German cattle farms proved that the ceratopogonid species Culicoides obsoletus was obviously the vector, since many females-fed and unfed ones-were found to be infected with this virus. This sudden outbreak of bluetongue disease (BTD) is surely not a primary result of global warming, but rather an effect of globalization-i.e. the intensive worldwide import and export of animals; but a hot summer, as in 2006, and a warm winter like that of the years 2006/2007 supported the new spread starting again in masses in August 2007 leading to 596 PCR-confirmed cases until then with more than 200,000 animals infected. Thus, new agents coming from elsewhere have only a chance to spread if appropriate vectors are available and the conditions remain favourable during a reasonably long period. Effects of global warming-of course-will support persistence of such outbreaks of diseases due to offering of spreading of imported viruses, bacteria and/or parasites.

A survey of biting midges of the genus Culicoides Latreille, 1809 (Diptera: Ceratopogonidae) in NE Bulgaria, with respect to transmission of avian haemosporidians

“…Many Culicoides spp. are vectors of BTV (Reoviridae: Orbivirus), a virus that can replicate in any ruminant, first detected in Central Europe in 2006 (Mehlhorn et al 2008). C. obsoletus, C. pulicaris and C. scoticus are considered the main vectors of BTV in Europe and their bloodmeals derived only from livestock (Mehlhorn et al 2007, Bartsch et al 2009).…”

Feeding patterns of biting midges of the Culicoides obsoletus and Culicoides pulicaris groups on selected farms in Brandenburg, Germany

“…Before the spread of bluetongue virus in various Northern European countries in the second half of 2006 (Mehlhorn et al 2008), it had been assumed that BT would be a mainly exotic disease transmitted by C. imicola. Arguably, increased economic globalisation accompanied by intensification of live animal transports for food production could have resulted in the appearance of a hitherto unknown exotic disease in Central and Northern Europe.…”

“…Their large spatial distribution across much of Europe could explain the rapid spread of bluetongue and may also entail future outbreaks (Wilson and Mellor 2008). Viral RNA has been detected in several species of Culicoides by Mehlhorn et al (2007Mehlhorn et al ( , 2008, Meiswinkel et al (2007), and Dijkstra et al (2008). More recently, Carpenter et al (2008) were able to demonstrate replication of viral loads in C. scoticus and C. obsoletus, which is considered to be a prerequisite for subsequent transmission.…”

Bluetongue: Virus proteins and recent diagnostic approaches

“…The clinical signs of bluetongue can easily be mistaken for those of other ruminant diseases such as orf (contagious pustular dermatitis), foot and mouth disease, acute photo sensitization, acute haemonchosis (with depression and submandibular oedema), facial eczema, Oestrus ovis infestation, pneumonia, plant poisoning, salmonellosis, sheep pox, Peste des Petits Ruminants (PPR) (Williamson et al, 2008), malignant catarrhal fever, pododermatitis, rinderpest, infectious bovine rhinotracheitis, bovine viral diarrhoea, bovine popular stomatitis, bovine herpes mamilitis and epizootic haemorrhagic disease of deer (Mehlhorn et al, 2008;Williamson et al, 2008;Savini et al, 2011).…”