Diagnostic Testing for Orthobunyaviruses in Ruminants
Orthobunyaviruses, including Schmallenberg virus (SBV) and Cache Valley virus (CVV), are often associated with reproductive losses and congenital defects in ruminants with arthrogryposis being commonly reported (Figure 1). SBV was first discovered in Germany in November 2011 and has since been reported in at least five European countries.1 Other symptoms of SBV infection may include newborn animals with neurologic symptoms ranging from flaccid paralysis to hyperexcitability, ataxia, and blindness.2 Although SBV has not been reported in North America, the virus could be introduced into the United States via an infected animal or arthropod vector. Accordingly, suspected cases should be reported to either the state veterinarian or the APHIS Veterinary Services Area Veterinarian-in-Charge. A guidance document containing additional information and a case definition for SBV can be found here: http://www.aphis.usda.gov/animal_health/animal_diseases/schmallenberg/downloads/
schmallenberg_case_definition_guidance.pdf. CVV causes clinical signs similar to SBV and is currently one of the leading causes of reproductive loss and arthrogryposis in ruminants in the United States. It is therefore important for the veterinary community to remain vigilant in monitoring for foreign pathogens such as SBV, as well as indigenous pathogens such as CVV. In an effort to better determine the presence and/or impact of orthobunyvirus infection in ruminants, researchers at the ISU CVM are providing some expanded orthobunyvirus diagnostic services on VDL submissions of fetuses, stillbirths, and neonates with clinical signs suggestive of SBV or CVV infection. Cases submitted to the ISU VDL that meet the criteria described below will receive a $100 credit toward fees for routine diagnostics related to the submission. Additionally, these cases will be tested for SBV and CVV infection at no additional charge to the submitter. If SBV or CVV is detected in the submitted samples (with confirmatory testing to be completed at the National Veterinary Services Laboratory in Ames, IA), the diagnostic results will be reported to the appropriate state and federal animal health officials as described in the guidance document.
To meet criteria for the $100 statement credit, submissions MUST include ALL of the following:
- An intact fetus/stillborn/neonate with arthrogryposis (bovine, ovine, or caprine)
- Fresh and formalin-fixed placenta
- Serum from the dam (and neonate if born live)
- A completed ISU VDL submission form with ‘Orthobunyvirus Project - Burrough’ noted on the form
Cases should be kept frozen or chilled and submitted to the ISU VDL as soon as possible using standard submission paperwork. Please note on the submission form ‘Orthobunyvirus Project - Burrough.’
Figure 1. Ovine fetus with arthrogryposis.
- Schmallenberg virus detected in sheep in England. Vet Rec. 2012;170(4):89.
- Gibbens, N. Schmallenberg virus: a novel viral disease in northern Europe. Vet Rec. 2012;170(2):58.