Venezuelan Equine Encephalitis Virus from South Florida

Abstract

Venezuelan equine encephalitis virus was isolated three times from the Culex (Melanoconion) species of mosquitoes collected in south Florida in June, July, and October, 1963. Specific antibody was present in 16 of 28 Peromyscus gossypinus (cotton mice) and 3 of 16 Sigmodon hispidus (cotton rats) sampled from one of the infected sites in January 1964.

Rodent-borne diseases and their risks for public health

“…In the USA (Chamberlain et al 1964)and Panama (Grayson and Galindo 1968), wild cotton rats (Sigmidon hispidus) are a host species for the mosquito (Culex species) that can also transfer the virus to humans. In Venezuela, antibodies were present in the Guaira spiny rat (Proechimys guairae), mouse oppossums (Marmosa spp), and common oppossums (Didelphis marsupialis) (Salas et al 2001).…”

Experimental Everglades Virus Infection of Cotton Rats (Sigmodon hispidus)

“…Recorded EVEV activity has been limited to South-Central Florida from Everglades National Park, north to Indian River County (Figure 1) ( 3 – 10 ). Although EVEV circulation in South Florida has been documented repeatedly, little is known about the dynamics of its ecology and transmission.…”

The Crab Hole Mosquito Blues

“…J) In contrast, in swampy or jungle areas (tropical wet forest) where a definable dry season does not occur normally in countries of Central America and eastern South America and in Panama, Mexico, the Florida Everglades, and several Caribbean islands, field studies by scientists at MARU ( 11 ), the Center for Disease Control (now Centers for Disease Control and Prevention, Atlanta, GA, USA) ( 12 ), the Trinidad Virus Research Laboratory (Port of Spain) ( 13 ), Rockefeller Foundation Laboratory (Belem, Brazil) ( 14 ), and the Gorgas Memorial Laboratory (Panama City, Panama) ( 15 ) had demonstrated presence of antigenically related VEE virus strains; resident equids in these sylvatic foci had antibody without signs of disease, but incursions by humans into these sylvatic or endemic areas often resulted in infections and disease. Sylvatic cycles were found in swampy areas in which floating species of water lettuce, Pistia stratiotes , provided appropriate habitat for mosquito species of the subgenus Culex ( Melanoconion ), the vectors of sylvatic subtypes and variants of VEE virus.…”