title: Contrasting sylvatic foci of Venezuelan equine encephalitis virus in northern South America.
abstract: The ecology of Venezuelan equine encephalitis (VEE) virus transmission was compared at three enzootic foci: two forest sites in the Catatumbo region of western Venezuela that have yielded small numbers of virus isolates since the 1970s, and another focus in the middle Magdalena Valley of Colombia that has consistently yielded many VEE virus isolates. Our results demonstrated dramatic differences in VEE virus isolation rates from sentinel hamsters, as well as differences in mosquito species composition and captured mammals with antibodies to VEE virus, between the Colombian and Venezuelan study sites. The higher isolation rate of enzootic VEE virus in the Colombian site was associated with a more abundant fauna of spiny rats (Proechimys spp.), known reservoir hosts of enzootic VEE virus. Mosquito collections demonstrated that the Colombian forest had a higher mosquito diversity and species evenness than either of the Venezuelan forests. The Colombian focus was especially richer in its Culex (Melanoconion) spp. fauna, a subgenus that includes all proven enzootic vectors for VEE virus. Our results suggest that the greater abundance, diversity, and stability of enzootic vector populations, combined with the greater density of rodent reservoir hosts, explains the higher levels of VEE virus circulation in the Colombian focus compared with the Venezuelan forests.
authors.affiliation: Instituto de Zoologia Tropical, Universidad Central de Venezuela, Caracas.
authors.forename: Roberto
authors.initials: R
authors.lastname: Barrera
authors.forename: Cristina
authors.initials: C
authors.lastname: Ferro
authors.forename: Juan-Carlos
authors.initials: JC
authors.lastname: Navarro
authors.forename: Jerome
authors.initials: J
authors.lastname: Freier
authors.forename: Jonathan
authors.initials: J
authors.lastname: Liria
authors.forename: Rosalba
authors.initials: R
authors.lastname: Salas
authors.forename: Marta
authors.initials: M
authors.lastname: Ahumada
authors.forename: Clovis
authors.initials: C
authors.lastname: Vasquez
authors.forename: Marta
authors.initials: M
authors.lastname: Gonzalez
authors.forename: Wenli
authors.initials: W
authors.lastname: Kang
authors.forename: Jorge
authors.initials: J
authors.lastname: Boshell
authors.forename: Scott C
authors.initials: SC
authors.lastname: Weaver
mesh_terms: D000818:Animals; D006224:Cricetinae; D009033:Culicidae / Q000821:virology; D004197:Disease Reservoirs; D004666:Encephalitis Virus, Venezuelan Equine / Q000302:isolation & purification*; D008647:Mesocricetus; D013020:South America; D013045:Species Specificity