|
|
||||||||
Following a 19-year hiatus, Venezuelan equine encephalitis (VEE) reemerged in western Venezuela in December 1992. This outbreak is important in understanding VEE emergence because phylogenetic studies imply that sympatric, enzootic, subtype ID VEE viruses mutated to generate the epizootic/epidemic. Although the 1992-1993 strains belong to subtype IC, a serotype implicated in extensive outbreaks during the 1960s and in 1995, relatively small numbers of human and equine cases occurred in 1992-1993. We, therefore, evaluated the pathogenicity of these Venezuelan enzootic ID and epizootic IC viruses to determine 1) if they exhibit phenotypes like those described previously for more distantly related enzootic and epizootic strains, and 2) if the 1992-1993 outbreak was limited by the inability of these IC viruses to exploit equines as amplification hosts. All strains were virulent in mice and guinea pigs, but were benign for cotton rats, natural hosts of enzootic viruses. However, only the IC strains produced equine disease, with mean peak viremias of 10(5) suckling mouse 50% lethal doses per mL serum, and some titers exceeding 10(7). These viremias approximate those observed previously with VEE strains isolated during more extensive epizootics, suggesting that efficient equine amplification did not limit the scope and duration of the 1992-1993 outbreak. Enzootic ID virus infection protected all horses from challenge with epizootic strain P676, supporting the hypothesis that epizootics bypass regions of enzootic transmission due to natural immunization of equines by enzootic VEE viruses.
This article has been cited by other articles:
![]() |
A. C. Moncayo, G. Lanzaro, W. Kang, A. Orozco, A. Ulloa, J. Arredondo-Jimenez, and S. C. Weaver Vector Competence of Eastern and Western Forms of Psorophora columbiae (Diptera: Culicidae) Mosquitoes for Enzootic and Epizootic Venezuelan Equine Encephalitis Virus Am J Trop Med Hyg, March 1, 2008; 78(3): 413 - 421. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. NI, N. E. YUN, M. A. ZACKS, S. C. WEAVER, R. B. TESH, A. P. T. DA ROSA, A. M. POWERS, I. FROLOV, and S. PAESSLER RECOMBINANT ALPHAVIRUSES ARE SAFE AND USEFUL SEROLOGICAL DIAGNOSTIC TOOLS Am J Trop Med Hyg, April 1, 2007; 76(4): 774 - 781. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Anishchenko, R. A. Bowen, S. Paessler, L. Austgen, I. P. Greene, and S. C. Weaver From the Cover: Venezuelan encephalitis emergence mediated by a phylogenetically predicted viral mutation PNAS, March 28, 2006; 103(13): 4994 - 4999. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Kuno and G.-J. J. Chang Biological Transmission of Arboviruses: Reexamination of and New Insights into Components, Mechanisms, and Unique Traits as Well as Their Evolutionary Trends Clin. Microbiol. Rev., October 1, 2005; 18(4): 608 - 637. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. P. Greene, S. Paessler, L. Austgen, M. Anishchenko, A. C. Brault, R. A. Bowen, and S. C. Weaver Envelope Glycoprotein Mutations Mediate Equine Amplification and Virulence of Epizootic Venezuelan Equine Encephalitis Virus J. Virol., July 15, 2005; 79(14): 9128 - 9133. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. WANG, S. PAESSLER, P. V. AGUILAR, D. R. SMITH, L. L. COFFEY, W. KANG, M. PFEFFER, J. OLSON, P. J. BLAIR, C. GUEVARA, et al. A NOVEL, RAPID ASSAY FOR DETECTION AND DIFFERENTIATION OF SEROTYPE-SPECIFIC ANTIBODIES TO VENEZUELAN EQUINE ENCEPHALITIS COMPLEX ALPHAVIRUSES Am J Trop Med Hyg, June 1, 2005; 72(6): 805 - 810. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. P. GREENE, S. PAESSLER, M. ANISHCHENKO, D. R. SMITH, A. C. BRAULT, I. FROLOV, and S. C. WEAVER VENEZUELAN EQUINE ENCEPHALITIS VIRUS IN THE GUINEA PIG MODEL: EVIDENCE FOR EPIZOOTIC VIRULENCE DETERMINANTS OUTSIDE THE E2 ENVELOPE GLYCOPROTEIN GENE Am J Trop Med Hyg, March 1, 2005; 72(3): 330 - 338. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. C. Brault, A. M. Powers, D. Ortiz, J. G. Estrada-Franco, R. Navarro-Lopez, and S. C. Weaver Venezuelan equine encephalitis emergence: Enhanced vector infection from a single amino acid substitution in the envelope glycoprotein PNAS, August 3, 2004; 101(31): 11344 - 11349. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Anishchenko, S. Paessler, I. P. Greene, P. V. Aguilar, A.-S. Carrara, and S. C. Weaver Generation and Characterization of Closely Related Epizootic and Enzootic Infectious cDNA Clones for Studying Interferon Sensitivity and Emergence Mechanisms of Venezuelan Equine Encephalitis Virus J. Virol., January 1, 2004; 78(1): 1 - 8. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Wang, A. C. Brault, A. M. Powers, W. Kang, and S. C. Weaver Glycosaminoglycan Binding Properties of Natural Venezuelan Equine Encephalitis Virus Isolates J. Virol., December 20, 2002; 77(2): 1204 - 1210. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. C. Brault, A. M. Powers, and S. C. Weaver Vector Infection Determinants of Venezuelan Equine Encephalitis Virus Reside within the E2 Envelope Glycoprotein J. Virol., May 15, 2002; 76(12): 6387 - 6392. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. C. Brault, A. M. Powers, E. C. Holmes, C. H. Woelk, and S. C. Weaver Positively Charged Amino Acid Substitutions in the E2 Envelope Glycoprotein Are Associated with the Emergence of Venezuelan Equine Encephalitis Virus J. Virol., February 15, 2002; 76(4): 1718 - 1730. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |