Surveillance of foot-and-mouth disease (FMD) in susceptible wildlife and domestic ungulates in Southeast of Bulgaria following a FMD case in wild boar

Following a foot-and-mouth disease (FMD) case of serotype O in wild boar in Southeast of Bulgaria, notified in January 2011 and eleven FMD outbreaks in livestock, a control and eradication plan according to the EU legislation was implemented. Based on the epidemiological considerations a “Cordon Sanitaire” along the border to Turkey, consisting of a defined infected area (1240 km2) and two areas of risk (2160 km2) was established. Within these areas a total of 812 wild boar, 68 roe deer, 7 red deer and 2 mouflons, hunted between February 2011 and January 2012, were tested for the presence of FMD. No FMD virus could be detected. Seropositive animals were found in wild boar (6.9%) and roe deer (4.4%), most of them spatially clustered around the FMD outbreaks in livestock, limited within a radius of 20 km. The outbreaks in domestic ungulates were controlled in the framework of EU legislation, including stamping out, standstill and no use of vaccination. All villages within the Cordon Sanitaire were examined for the presence of FMD according to the control and eradication plan. Neither clinical signs nor seroconversion was detected and the region could regain its status of FMD freedom without vaccination. The relatively low seroprevalence and clustered spatial distribution of seropositive wild boar and roe deer suggest that the FMD infection in wildlife was mainly a short living event, which failed to develop into a large scale epidemic.