Spatial and temporal distribution of bluetongue and its Culicoides vectors in Bulgaria.

Surveillance of Culicoides (Diptera: Ceratopogonidae) biting midges was carried out between 2001 and 2003, at 119 sites within a 50 x 50-km grid distributed across Bulgaria, using light trap collections around the time of peak adult midge abundance. Sentinel and ad hoc serum surveillance of hosts susceptible to bluetongue infection was carried out at around 300 sites between 1999 and 2003. Following the initial incursion of bluetongue virus 9 (BTV-9) into Bourgas province in 1999, affecting 85 villages along the southern border, a further 76 villages were affected along the western border in 2001, with outbreaks extending as far north as 43.

Epizootiological control of bluetongue disease in Bulgaria in 2002.

In accordance with the National Surveillance Programme for the control of bluetongue (BT) disease in 2002, serum surveillance was performed in 22 sentinel, seronegative animal herds located in western Bulgaria. These herds were at least 40 km outside the settlements affected by the 2001 epidemic. Another 42 sentinel villages (herds) were established in southern Bulgaria in a 10 km border strip zone in the Bourgas, Yambol, Haskovo, Kardjali, Smolyan and Blagoevgrad Districts.