Trajectory analysis and bluetongue virus serotype 2 in Florida 1982.

Examination of Northern Hemisphere synoptic charts and computation of backward trajectories indicated that Culicoides infected with bluetongue virus serotype 2 could have been carried on the wind and brought the virus to Florida on the afternoon of August 19, 1982 after leaving northern Cuba the previous evening. Flight would have occurred at a height of 1-1.5 km at temperatures of 15-17 degrees C. The distance of 500 km from northern Cuba to Ona would have been covered in 20 h at an average speed of 25 km h-1. Computation of trajectories indicated that a second electropherotype, Ona B, was unlikely to have been introduced by infected Culicoides.