Midge-borne virus threat to livestock, farmers warned
A deadly disease is expected to sweep through Northern Ireland's livestock herds and flocks this spring – once the midges that carry it are on the wing this spring.
Schmallenberg virus was identified in Germany in late 2011 and has already reached Northern Ireland, with the first case detected in a cattle herd in Co Down in October last year.
Scientists made a positive identification of the virus after a malformed calf was born on a Co Down farm and the infection has been confirmed in counties Cork, Wexford, Kilkenny, Wicklow and Waterford.
The virus, transmitted by biting midges, can cause the birth of malformed calves and lambs.
Scientists at the Agri-Food and Biosciences Institute in Northern Ireland expect to see the virus spread quickly once the midges that transmit it are active – between April and December. They are calling on farmers who suspect the virus may be present in their flocks and herds to discuss the action they should take with their vet.
"The first positive case in Northern Ireland was detected in a cattle herd in Co Down in late October 2012 – this remains the only confirmed case in the province," an AFBI spokesman said.
Authorities in the Republic have data suggesting that the greatest risk of exposure of animals to Schmallenberg virus was in the south and south-east of Ireland towards the end of the 2012 vector season, AFBI said. "Further spread to unaffected herds and flocks throughout Northern Ireland and the Republic of Ireland is very likely to occur during the 2013 vector season but should have relatively little impact in non-pregnant livestock," the spokesman said.
"Exposed animals develop a strong immunity and are unlikely to suffer any ill-effects if exposed to the virus on a subsequent occasion. If this viral infection becomes endemic the ill-effects are likely to be confined to younger animals and cows or ewes that have not been previously exposed.
"Problems with malformed calves and lambs are most likely to arise when pregnant cows and sheep are exposed to the virus during a critical time window in early to mid-pregnancy – 40 to 120 days gestation in cattle and 20 to 80 days gestation in sheep.
"Farmers who suspect they have problems caused by SBV should discuss with their private veterinary practitioners what action they should take, including on the submission of samples to the Agri-Food and Biosciences Institute (AFBI) veterinary laboratories at Omagh and Stormont," the spokesman said.
"A risk assessment produced jointly by the European Centre for Disease Prevention and Control (ECDC), the Robert Koch Institute (RKI), Germany, and the National Institute of Public Health and the Environment (RIVM), Netherlands, concluded that it is very unlikely that SBV poses a risk to humans."
• Schmallenberg virus is caused by a group of viruses not found in northern Europe until 2011.
• Vectored by midges, which are indigenous to NI and active during April to early December.
• Led to fever, diarrhoea and milk-drop in cows in summer 2011.
• Other risks include more lambs, calves, kids born dead or weak, at or near due date; also lambs, calves and kids born with varying degrees of fused or stiff limb joints, twisted spines, or abnormal skulls or jaws
• Cases have been confirmed around Europe, including the Republic of Ireland and the United Kingdom (including Northern Ireland).