Virulence and viremia characteristics of 1992 epizootic subtype IC Venezuelan equine encephalitis viruses and closely related enzootic subtype ID strains.
Abstract: 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.
Publication Date: 2001-08-16 PubMed ID: 11504410DOI: 10.4269/ajtmh.2001.65.64Google Scholar: Lookup
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- Journal Article
- Research Support
- U.S. Gov't
- Non-P.H.S.
- Research Support
- U.S. Gov't
- P.H.S.
Summary
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The article reveals a research study about Venezuelan equine encephalitis (VEE) which reappeared in Venezuela in 1992 after a 19-year pause. The study investigates the pathogenicity of the enzootic ID and epizootic IC VEE virus strains identified in the 1992-1993 outbreak, assessing if constraints in equine amplification could have limited the spread of the outbreak.
Understanding Venezuelan Equine Encephalitis (VEE)
- VEEs are viruses that have caused significant disease outbreaks in the past. This research primarily focuses on subtype IC, which was involved in extensive outbreaks during the 1960s and in 1995, and the enzootic subtype ID. These enzootic viruses are believed to have mutated to cause the 1992-1993 outbreak.
- Despite the devastating potential of subtype IC, the outbreak in 1992-1993 only led to a moderate number of human and equine cases. This study explores the reasons behind the comparatively limited impact of the outbreak.
Assessing Virulence and Viremia
- The researchers examined how these viruses affect different animals like mice, guinea pigs, and cotton rats and evaluated their virulence and viremia levels. Viremia refers to the presence of viruses in the bloodstream, which may lead to disease transmission.
- All the VEE strains were identified as virulent for mice and guinea pigs. Still, they did not impact cotton rats, which are the natural hosts of enzootic viruses. In contrast, only the IC strains showed potential to cause disease in horses.
Role of Equine Amplification
- The IC strains’ ability to cause disease in equines was of particular interest because horses can serve as amplification hosts, promoting the virus’s spread in the environment.
- The results suggest that the IC strains could lead to high viremia levels in horses (similar to those observed during more extensive outbreaks). This implies that limitations in equine amplification did not impact the scope and duration of the 1992-1993 outbreak.
Impact of Natural Immunization
- The study finds that horses infected with the enzootic ID virus strain developed immunity against an epizootic strain, P676.
- This result supports the theory that areas with enzootic transmission might be protected from wider epidemics due to the natural immunization of horses against the VEE virus.
Cite This Article
APA
Wang E, Bowen RA, Medina G, Powers AM, Kang W, Chandler LM, Shope RE, Weaver SC.
(2001).
Virulence and viremia characteristics of 1992 epizootic subtype IC Venezuelan equine encephalitis viruses and closely related enzootic subtype ID strains.
Am J Trop Med Hyg, 65(1), 64-69.
https://doi.org/10.4269/ajtmh.2001.65.64 Publication
Researcher Affiliations
- Department of Pathology and Center for Tropical Diseases, The University of Texas Medical Branch, Galveston 77555-0609, USA.
MeSH Terms
- Animals
- Anopheles
- Chlorocebus aethiops
- Cricetinae
- Disease Outbreaks / veterinary
- Encephalitis Virus, Venezuelan Equine / classification
- Encephalitis Virus, Venezuelan Equine / pathogenicity
- Encephalomyelitis, Venezuelan Equine / blood
- Encephalomyelitis, Venezuelan Equine / epidemiology
- Encephalomyelitis, Venezuelan Equine / virology
- Female
- Guinea Pigs
- Horse Diseases / blood
- Horse Diseases / epidemiology
- Horse Diseases / virology
- Horses
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Random Allocation
- Rats
- Rodent Diseases / virology
- Sigmodontinae
- Venezuela / epidemiology
- Vero Cells
- Viremia / virology
- Virulence
Grant Funding
- AI39800 / NIAID NIH HHS
- T32 AI-07536 / NIAID NIH HHS
Citations
This article has been cited 29 times.- Haines CA, Campos RK, Azar SR, Warmbrod KL, Kautz TF, Forrester NL, Rossi SL. Venezuelan Equine Encephalitis Virus V3526 Vaccine RNA-Dependent RNA Polymerase Mutants Increase Vaccine Safety Through Restricted Tissue Tropism in a Murine Model.. Zoonoses (Burlingt) 2022;2.
- Glud HA, George S, Skovgaard K, Larsen LE. Zoonotic and reverse zoonotic transmission of viruses between humans and pigs.. APMIS 2021 Dec;129(12):675-693.
- Chapman GE, Sherlock K, Hesson JC, Blagrove MSC, Lycett GJ, Archer D, Solomon T, Baylis M. Laboratory transmission potential of British mosquitoes for equine arboviruses.. Parasit Vectors 2020 Aug 12;13(1):413.
- More S, Bøtner A, Butterworth A, Calistri P, Depner K, Edwards S, Garin-Bastuji B, Good M, Gortázar Schmidt C, Michel V, Miranda MA, Nielsen SS, Raj M, Sihvonen L, Spoolder H, Stegeman JA, Thulke HH, Velarde A, Willeberg P, Winckler C, Baldinelli F, Broglia A, Dhollander S, Beltrán-Beck B, Kohnle L, Morgado J, Bicout D. Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): Venezuelan equine encephalitis.. EFSA J 2017 Aug;15(8):e04950.
- Rusnak JM, Glass PJ, Weaver SC, Sabourin CL, Glenn AM, Klimstra W, Badorrek CS, Nasar F, Ward LA. Approach to Strain Selection and the Propagation of Viral Stocks for Venezuelan Equine Encephalitis Virus Vaccine Efficacy Testing under the Animal Rule.. Viruses 2019 Aug 31;11(9).
- Kautz TF, Guerbois M, Khanipov K, Patterson EI, Langsjoen RM, Yun R, Warmbrod KL, Fofanov Y, Weaver SC, Forrester NL. Low-fidelity Venezuelan equine encephalitis virus polymerase mutants to improve live-attenuated vaccine safety and efficacy.. Virus Evol 2018 Jan;4(1):vey004.
- Beckham JD, Tyler KL. Arbovirus Infections.. Continuum (Minneap Minn) 2015 Dec;21(6 Neuroinfectious Disease):1599-611.
- Reed DS, Glass PJ, Bakken RR, Barth JF, Lind CM, da Silva L, Hart MK, Rayner J, Alterson K, Custer M, Dudek J, Owens G, Kamrud KI, Parker MD, Smith J. Combined alphavirus replicon particle vaccine induces durable and cross-protective immune responses against equine encephalitis viruses.. J Virol 2014 Oct;88(20):12077-86.
- Shafagati N, Patanarut A, Luchini A, Lundberg L, Bailey C, Petricoin E 3rd, Liotta L, Narayanan A, Lepene B, Kehn-Hall K. The use of Nanotrap particles for biodefense and emerging infectious disease diagnostics.. Pathog Dis 2014 Jul;71(2):164-76.
- Weaver SC, Winegar R, Manger ID, Forrester NL. Alphaviruses: population genetics and determinants of emergence.. Antiviral Res 2012 Jun;94(3):242-57.
- Brooke CB, Schäfer A, Matsushima GK, White LJ, Johnston RE. Early activation of the host complement system is required to restrict central nervous system invasion and limit neuropathology during Venezuelan equine encephalitis virus infection.. J Gen Virol 2012 Apr;93(Pt 4):797-806.
- Aguilar PV, Estrada-Franco JG, Navarro-Lopez R, Ferro C, Haddow AD, Weaver SC. Endemic Venezuelan equine encephalitis in the Americas: hidden under the dengue umbrella.. Future Virol 2011;6(6):721-740.
- Sherman MB, Weaver SC. Structure of the recombinant alphavirus Western equine encephalitis virus revealed by cryoelectron microscopy.. J Virol 2010 Oct;84(19):9775-82.
- Brooke CB, Deming DJ, Whitmore AC, White LJ, Johnston RE. T cells facilitate recovery from Venezuelan equine encephalitis virus-induced encephalomyelitis in the absence of antibody.. J Virol 2010 May;84(9):4556-68.
- Quiroz E, Aguilar PV, Cisneros J, Tesh RB, Weaver SC. Venezuelan equine encephalitis in Panama: fatal endemic disease and genetic diversity of etiologic viral strains.. PLoS Negl Trop Dis 2009 Jun 30;3(6):e472.
- Schäfer A, Whitmore AC, Konopka JL, Johnston RE. Replicon particles of Venezuelan equine encephalitis virus as a reductionist murine model for encephalitis.. J Virol 2009 May;83(9):4275-86.
- Anishchenko M, Bowen RA, Paessler S, Austgen L, Greene IP, Weaver SC. Venezuelan encephalitis emergence mediated by a phylogenetically predicted viral mutation.. Proc Natl Acad Sci U S A 2006 Mar 28;103(13):4994-9.
- Kuno G, Chang GJ. Biological transmission of arboviruses: reexamination of and new insights into components, mechanisms, and unique traits as well as their evolutionary trends.. Clin Microbiol Rev 2005 Oct;18(4):608-37.
- Greene IP, Paessler S, Austgen L, Anishchenko M, Brault AC, Bowen RA, Weaver SC. Envelope glycoprotein mutations mediate equine amplification and virulence of epizootic venezuelan equine encephalitis virus.. J Virol 2005 Jul;79(14):9128-33.
- Carrara AS, Gonzales G, Ferro C, Tamayo M, Aronson J, Paessler S, Anishchenko M, Boshell J, Weaver SC. Venezuelan equine encephalitis virus infection of spiny rats.. Emerg Infect Dis 2005 May;11(5):663-9.
- Coffey LL, Carrara AS, Paessler S, Haynie ML, Bradley RD, Tesh RB, Weaver SC. Experimental Everglades virus infection of cotton rats (Sigmodon hispidus).. Emerg Infect Dis 2004 Dec;10(12):2182-8.
- Weaver SC, Barrett AD. Transmission cycles, host range, evolution and emergence of arboviral disease.. Nat Rev Microbiol 2004 Oct;2(10):789-801.
- Brault AC, Powers AM, Ortiz D, Estrada-Franco JG, Navarro-Lopez R, Weaver SC. Venezuelan equine encephalitis emergence: enhanced vector infection from a single amino acid substitution in the envelope glycoprotein.. Proc Natl Acad Sci U S A 2004 Aug 3;101(31):11344-9.
- Anishchenko M, Paessler S, Greene IP, Aguilar PV, Carrara AS, Weaver SC. 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 2004 Jan;78(1):1-8.
- Gonzalez-Salazar D, Estrada-Franco JG, Carrara AS, Aronson JF, Weaver SC. Equine amplification and virulence of subtype IE Venezuelan equine encephalitis viruses isolated during the 1993 and 1996 Mexican epizootics.. Emerg Infect Dis 2003 Feb;9(2):161-8.
- Ferro C, Boshell J, Moncayo AC, Gonzalez M, Ahumada ML, Kang W, Weaver SC. Natural enzootic vectors of Venezuelan equine encephalitis virus, Magdalena Valley, Colombia.. Emerg Infect Dis 2003 Jan;9(1):49-54.
- Wang E, Brault AC, Powers AM, Kang W, Weaver SC. Glycosaminoglycan binding properties of natural venezuelan equine encephalitis virus isolates.. J Virol 2003 Jan;77(2):1204-10.
- Brault AC, Powers AM, Weaver SC. Vector infection determinants of Venezuelan equine encephalitis virus reside within the E2 envelope glycoprotein.. J Virol 2002 Jun;76(12):6387-92.
- Brault AC, Powers AM, Holmes EC, Woelk CH, Weaver SC. Positively charged amino acid substitutions in the e2 envelope glycoprotein are associated with the emergence of venezuelan equine encephalitis virus.. J Virol 2002 Feb;76(4):1718-30.
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