FIG. 1.

Map of the regions of Venezuela and Colombia affected by the 1962–1964 and 1995 outbreaks. Sites of isolation of the VEEV subtype IC isolates that we studied are identified by boxed strain names. The following bold numbers show the states involved in both the 1962–1964 and 1995 outbreaks: 1, Guajira (Colombia); 2, Zulia; 3, Trujillo; 4, Falcon; 5, Lara; 6, Portuguesa; 7, Yaracuy; 8, Carabobo; 9, Cojedes; and 10, Guarico. The following numbers show states involved only in the 1962–1964 outbreak: 11, Aragua; 12, Miranda; 13, Anzoategui; 14, Sucre; 15, Monagas; and 16, Delta Amacuro.