Prevalence of enzootic bovine leukosis in the Republic of Bulgaria in 1997-2004

The serological investigations using the agar gel immunodiffusion (AGID) test performed in the Republic of Bulgaria in the period 1997-2004 showed a high prevalence of enzootic bovine leukosis (EBL), from 8.47% in 1997 to 22.26% in 2004. The highest percentage of seroreagents was observed in the regions of Silistra (48.61%), Dobrich (47.57%) and Burgas (47.32%), with the lowest, in the regions of Pazardjik (0.28%), Kyustendil (1.89%) and Smolyan (1.95%). Leukosis infection was found to be more prevalent in Eastern than in Western Bulgaria. The total EBL epidemic foci in 2004 numbered more than 600.Depending on the severity of the epidemiological process, the eradication of leukosis in the country could be achieved in 5 to 10 years with sufficient financial funding and strict realization of the National programme for prophylaxis and control of EBL.