Controlling EVA in the 21st century: ‘zero tolerance’ or ‘live and let live’?

At the time of writing in August 2007, when foot and mouth disease virus (FMDV) has apparently escaped from biologically secure research or vaccine production facilities to nearby cattle in the UK and bluetongue virus (BTV) continues to infect livestock in its second season after over-wintering in northern Europe, the importance of controlling infectious diseases of animals through measures such as ‘heightened surveillance’, ‘optimal biosecurity’ and ‘vaccination’ is firmly in the dual spotlights of scientific and public scrutiny. Although they may not obviously or directly affect horses, these latest livestock disease outbreaks should act as an important alarm call to the equine veterinary and research communities for vigilance and preparedness to deal with equivalent situations in the equine species. To this end, since March 2007 the UK equine welfare charity, The Horse Trust, has been campaigning to raise awareness and develop contingency planning for the threat to the UK and Europe from African horse sickness virus, a highly fatal midge-borne infection of horses that is closely related to BTV. At the same time as we have seen the re-emergence of these high profile outbreaks of infection by FMDV and BTV, the potentially economically and clinically important infectious disease equine viral arteritis (EVA) (Timoney and McCollum 1990) has been recognised since late June 2007 among non-Thoroughbred horses in France (International Collating Centre, Newmarket). At the time of writing 16 equine premises in Normandy had been identified with infection with equine arteritis virus (EAV), with many of the cases being clinically apparent and clear epidemiological links between most outbreaks identified. The EVA outbreak currently unfolding in France acts as a timely backdrop for this commentary, which in considering approaches to control of EVA hopes that, as with all outbreaks, lessons can be learned so that not only are diseases dealt with effectively when they occur but that they may actually be prevented through measured and affordable actions.