| investigations on outbreaks of african horse sickness in the surveillance zone in south africa. | confirmed outbreaks of african horse sickness (ahs) occurred in the surveillance zone of the western cape in 1999 and 2004, both of which led to a two-year suspension on the export of horses. light trap surveys in the outbreak areas showed that known vector competent culicoides species, notably c. imicola, were abundant and present in numbers equal to those in the traditional ahs endemic areas. isolations of ahs virus serotypes 1 and 7, equine encephalosis virus, and bluetongue virus from field- ... | 2006 | 17361773 |