Blue Tongue Virus Update – June 2016
GOAT VETERINARY SOCIETY – BLUETONGUE UPDATE.
Chairman David Harwood attended a briefing meeting at Nobel House on behalf of GVS, presentations were received from the following:
- Nigel Gibbens, (UK CVO) – introduction and acted as chairman.
- Helen Roberts (APHA) – described the situation in France.
- John Fishwick (BVA) – described the disease and its clinical signs.
- Simon Carpenter (Pirbright) – discussed the current scientific knowledge.
- Minette Cooper (NFU) – described the “Jab Campaign.”
Some really useful advice – which will be updated on a regular basis – can be found by following the weblinks below:
Points of interest:
- The initial incursion of BTV8 into Europe occurred in 2006 – causing an epizootic between 2006 and 2008, mainly in France and Germany – but also resulted in a relatively small number of cases in the UK.
- Since then – the outbreak died down until Aug 2015 when BTV8 was again identified in France – Pirbright state that the virus is “almost identical” to the strain originally identified. The outbreak died down during the winter months, but intensive surveillance throughout France has now identified a current figure of 277 farms on which BTV8 has been confirmed.
- Interestingly – only 7 cattle and 4 sheep have exhibited typical clinical signs, on all other holdings, there is only serological evidence of exposure.
- What is the source of the current infection? – almost certainly the virus has been circulating in the background – either asymptomatically in domestic or wild animals in which it is known to replicate – Pirbright seem confident that this is NOT a new infection.
- REMINDER – this is essentially a midge borne disease, and as such – it is the airborne movement of midges that poses the greatest risk to UK incursion.
- Defra are undertaking regular epidemiological, mathematical and meteorological monitoring – and currently suggest a likelihood of the virus reaching the UK of from 5% in May – to 80% by September.
- As a result – the current drive is to make vaccine available in preparation for its likely arrival. Four companies apparently manufacture a BTV8 vaccine – with two companies (Zoetis “Zulvac 8” and MSD “Bluevac BTV8”) expected to become available by mid July.
- Current data sheet recommendations are similar for each – but NEITHER have a marketing authorisation for use in goats – with the expectation that they can be used under cascade and at the discretion of the private vet in discussion with the owner – both vaccines will be POM only.
- Personal information from one vaccine manufacturer is that goats should be vaccinated using the recommendations for sheep, these are:
- First injection from 6 weeks of age.
- Second injection after 3 weeks.
- Onset of immunity 25 days after administration of second dose.
- Duration of immunity in sheep is likely to be at least one year – no data for duration of immunity in goats).
- Vaccination will be on a voluntary basis.
- Serology will not be able to differentiate between antibody following natural infection and vaccinal antibody.
- During the last incursion – much was made of the alternative means of control – by reducing possible midge activity around livestock. The Pirbright speaker stated that this was largely ineffective – insecticides gave only minimal protection, although housing may help – its minimal impact needs to be balanced with the possible negative aspects of denying access to grazing. The midges themselves multiply in dung heaps, compost and leaf litter.
- The disease in the UK is notifiable – any owner or veterinary surgeon suspecting BTV infection in the coming months should report their SUSPICION.
- The clinical signs in sheep and cattle are given in the attached links – disease in goats has rarely been reported – and although likely to target the same anatomical sites – was described as “relatively mild” during the outbreak in Holland in which goats were affected. I have attached a single slide I prepared (with Dan Derckson’s permission) after his presentation to GVS.
- In the coming weeks – a series of “JAB” (Joint action against Bluetongue) meetings are to be held around the country – details can be found on the NFU link earlier.
- We asked about the likely impact on our export trade, potentially complicated by vaccination – and were told that it is a bilateral decision – i.e. any trade of live animals or germplasm should be agreed by exporter and importing country – possibly in advance rather than last minute. Any such BTV vaccination for export would (I understand) need to be undertaken by a vet.
If there are any questions / queries – I will endeavour to answer these via GVS secretary Ben Dustan.
GVS Chairman 18th June 2016.