RESUMEN
Venezuelan equine encephaltis (VEE) virus was isolated from sentinel hamsters exposed in the Rio de Oro region of Colombia, in the Lake Maracaibo drainage área near the border with Venezuela, in 1983-13 years after the first strain was isolated from the region near Tibu. Hydroxylapatite elution profiles of three isolates from the Rio de Oro region were typical of enzootic strains. Relative abundance data and past isolations suggest that culex (Melanoconion) pedroi is a probable enxootic vector at this focus. The virus was no isolated from forests near Santa Marta and Magangue in the Rio Magdalena drainage área in 1983-9 and 16 years, respectively, after the last previous isolations in those áreas. However, equine animals 2 to 10 years of age and humans 25 to 67 years of age living near the Magangue field study área were positive for VEE virus-specific neutralizing antibodies