Novel Orthobunyavirus in Cattle, Europe, 2011 Bernd Hoffmann, 1 Matthias Scheuch, 1 Dirk Höper, Ralf Jungblut, Mark Holsteg, Horst Schirrmeier, Michael Eschbaumer, Katja V. Goller, Kerstin Wernike, Melina Fischer, Angele Breithaupt, Thomas C. Mettenleiter, and Martin Beer In 2011, an unidentified disease in cattle was reported in Germany and the Netherlands. Clinical signs included fever, decreased milk production, and diarrhea. Metagenomic analysis identified a novel orthobunyavirus, which subsequently was isolated from blood of affected animals. Surveillance was initiated to test malformed newborn animals in the affected region. I n summer and autumn 2011, farmers and veterinarians in North Rhine-Westphalia, Germany, and in the Netherlands reported to the animal health services, local diagnostic laboratories, and national research institutes an unidentified disease in dairy cattle with a short period of clear clinical signs, including fever, decreased milk production, and diarrhea. All classical endemic and emerging viruses, such as pestiviruses, bovine herpesvirus type 1, foot-and-mouth disease virus, bluetongue virus, epizootic hemorrhagic disease virus, Rift Valley fever virus, and bovine ephemeral fever virus, could be excluded as the causative agent. To identify the cause of the disease, we analyzed blood samples from affected cattle. The Study On a farm near the city of Schmallenberg (North Rhine-Westphalia, Germany; Figure 1), 3 blood samples obtained in October 2011 from dairy cows that had clinical signs at sampling (Table, BH 80/11) were pooled and analyzed by using metagenomics. We also investigated a blood sample from a healthy animal from a different farm (Table, BH 81/11). For metagenomic analysis, 4 sequencing libraries (Table) were prepared and sequenced by using the 454 Genome Sequencer FLX (Roche, Mannheim, Germany). Two libraries each were generated from DNA and RNA isolated from plasma samples (Table). By using a combination of BLAST (1) and sequence mapping with the 454 reference mapper application (version 2.6; Roche), reads were classified into different superkingdoms (Table). In addition to the anticipated high number of host sequences, we detected in some samples a considerable portion of reads representing diverse bacterial species. These bacteria most likely grew in the samples during the prolonged storage before extraction of the nucleic acids used to prepare the sequencing libraries. Seven orthobunyavirus sequences were detected in the library prepared from pooled RNA from 3 animals of 1 farm (BH 80/11, Table). Repeated sequencing of this library resulted in 22 additional reads of orthobunyavirus-specific sequences. We assembled the reads of all 3 genome segments into contigs by using the Newbler Assembler Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 18, No. 3, March 2012 469 Author affiliations: Friedrich-Loeffler-Institut, Greifswald–Insel Riems, Germany (B. Hoffmann, M. Scheuch, D. Höper, H. Schirrmeier, M. Eschbaumer, K.V. Goller, K. Wernike, M. Fischer, A. Breithaupt, T.C. Mettenleiter, M. Beer); State Veterinary Diagnostic Laboratory, Arnsberg, Germany (R. Jungblut); and Chamber of Agriculture for North Rhine-Westphalia, Bovine Health Service, Bonn, Germany (M. Holsteg) DOI: http://dx.doi.org/10.3201/eid1803.111905 1 These authors contributed equally to this article. Figure 1. Location of farms with PCR-positive cattle (blue dots) in North Rhine-Westphalia, Germany.