APHA are following up their enhanced surveillance for SBV in small ruminants, with a similar approach with cattle. The following information has been sent to veterinary practices in England and Wales.
Schmallenberg virus (SBV) was first identified in 2011 and the disease subsequently spread widely throughout Europe. During the 2012 and 2013 lambing and calving seasons, there were numerous cases of congenital defects in lambs and calves (arthrogryposis, spinal defects, hydranencephaly and micromyelia) due to in-utero exposure to SBV in UK flocks and herds.
In the summer of 2016, SBV re-emerged, resulting in the birth of typically affected lambs and calves the following year. APHA provided free PCR testing for lambs fitting the case description. The results of this enhanced surveillance are available on the Vet Gateway.
There is a recognized pattern of 3-5 year cycles with endemically established viral vector borne (arbovirus) diseases. This pattern suggested the possibility of another wave of infection, which would manifest itself this lambing and calving season. SBV has already been detected by PCR testing in lambs and a calf in at four post-mortem centres.
Following on from the announced enhanced surveillance for SBV in small ruminants, APHA will also offer to test cattle samples free of charge. A fresh brain sample will be tested free of charge, if submitted to APHA from calves with arthrogryposis and/or spinal defects. Please include the details of the herd size, the number affected and the number potentially at risk on the submission form.
Since the detection of the virus in the foetal brain depends on the stage of gestation when the foetus became infected, a negative PCR test would not rule out in utero infection. Therefore, in addition, serum samples can also be submitted from up to six cows/heifers, including any that have aborted a calf (particularly those with the gross pathology described above), so that we may also be able to test these to detect antibodies to SBV in the dam.
Please contact your local VIC for more information and to discuss appropriate sampling, and to discuss whether the submission of a foetus is more appropriate (to investigate other causes of abortion in addition to SBV).
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