Venezuelan equine encephalomyelitis in Florida: endemic virus circulation in native rodent populations of Everglades hammocks
Bigler, W.J.; Ventura, A.K.; Lewis, A.L.; Wellings, F.M.; Ehrenkranz, N.J.
American Journal of Tropical Medicine and Hygiene 23(3): 513-521
1974
ISSN/ISBN: 0002-9637 PMID: 4150911 Document Number: 74667
VEE virus activity was monitored in rodent populations in the everglades community of Pinecrest, Florida. Tagged cotton mice (Peromyscus gossypinus) and cotton rats (Sigmodon hispidus) were periodically trapped and bled serially for up to 17 months. Serum samples were surveyed for virus and tested for antibody in HI and neutralization tests. The virus circulated at low levels in the spring and early summer when the rodent populations were at their highest density, with a peak of activity between July and October when the declining populations were composed mostly of mature breeding individuals. In cotton mice an antibody rate of 70% to 80% could fall to less than 20% the following spring. Such a population then had the potential for annual reintroduction, circulation and amplification of VEE virus. Various species of mammals and water birds, latent infection in small mammals, water levels, and relative mosquito density are discussed as mechanisms contributing to the dissemination of virus. Another paper (pp. 507-512 of the same journal) deals with human VEE virus infection in Florida.