† Instituto Venezolano de Investigaciones Cientificas, Centro de Microbiologia y Biologia Celular, Laboratorio de Virus Animales, Apartado 1827, Caracas 1010 A, Venezuela
‡ Division of Vector-Borne Viral Diseases, Center for Infectious Diseases, Centers for Disease Control, Public Health Service, U.S. Department of Health and Human Services, Post Office Box 2087, Fort Collins, Colorado 80522-2087
Increasing utilization of arable land in southwestern Venezuela has led to a potential increase in human exposure to arbovirus infections. Since previous studies in the Catatumbo region of this area documented the presence of eastern equine encephalitis (EEE) and Venezuelan equine encephalitis (VEE) viruses, an attempt was made to study the transmission and maintenance of these viruses from 1973 to 1981. Isolations of EEE, VEE ID strains, Una, Itaqui, and Moju viruses were repeatedly obtained from mosquitoes, mostly Culex (Melanoconion) spp. and sentinel hamsters. The results indicate that these viruses constitute a potential hazard to public health in the area. Further, the strategic location of the Catatumbo region, between enzootic tropical foci of arboviruses, may provide circumstances and conditions for study of both enzootic maintenance and movement of these viruses.