Vev y Denv

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Future Virol. Author manuscript; available in PMC 2011 November 1.
Published in final edited form as: Future Virol. 2011 ; 6(6): 721–740. doi:10.2217/FVL.11.5.

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Endemic Venezuelan equine encephalitis in the Americas: hidden under the dengue umbrella
Patricia V Aguilar1,2, Jose GEstrada-Franco1,2, Roberto Navarro-Lopez3, Cristina Ferro4, Andrew D Haddow1,2, and Scott C Weaver1,2,† 1 Center for Tropical Diseases, Institute for Human Infections & Immunity, University of Texas Medical Branch, Galveston, TX, USA
2 3

Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA

Comision Mexico-Estados Unidos para la Prevencion de la Fiebre Aftosa &Otras Enfermedades Exoticas de los Animales, Mexico City, Mexico
4

Instituto Nacional de Salud, Bogota, Colombia

Abstract
Venezuelan equine encephalitis (VEE) is an emerging infectious disease in Latin America. Outbreaks have been recorded for decades in countries with enzootic circulation, and the recent implementation of surveillance systems has allowed the detection of additional humancases in countries and areas with previously unknown VEE activity. Clinically, VEE is indistinguishable from dengue and other arboviral diseases and confirmatory diagnosis requires the use of specialized laboratory tests that are difficult to afford in resource-limited regions. Thus, the disease burden of endemic VEE in developing countries remains largely unknown, but recent surveillance suggeststhat it may represent up to 10% of the dengue burden in neotropical cities, or tens-of-thousands of cases per year throughout Latin America. The potential emergence of epizootic viruses from enzootic progenitors further highlights the need to strengthen surveillance activities, identify mosquito vectors and reservoirs and develop effective strategies to control the disease. In this article, weprovide an overview of the current status of endemic VEE that results from spillover of the enzootic cycles, and we discuss public health measures for disease control as well as future avenues for VEE research.

Keywords alphavirus; encephalitis; endemic; epizootic; mosquito; surveillance Venezuelan equine encephalitis virus (VEEV) is a member of the family Togaviridae, genus Alphavirus, and is oneof the virus species in the VEE complex. This complex also includes Mosso das Pedras, Cabassou, Everglades, Mucambo, Pixuna and Rio Negro species (Table 1). Each of these subtypes demonstrates unique characteristics with respect to ecology,

© 2011 Future Medicine Ltd † Author for correspondence: sweaver@utmb.edu. Financial & competing interests disclosure SC Weaver is an applicant for thepatent of a vaccine designed to protect against Venezuelan equine encephalitis. The authors’ research is supported by NIH grants AI48807 and AI057156. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. Nowriting assistance was utilized in the production of this manuscript.

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epidemiology and virulence in both humans and equids, and most are known to cause both animal and/or human disease ranging from febrile illness to encephalitis.

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Viruses

Venezuelan equine encephalitis virus was first isolated in 1938 from the brain of a horse that diedof encephalitis [1,2]. However, clinical disease in equids, referred as ‘peste loca’, was documented in South America in the 1920s [3,4]. In 1950, the virus was isolated from human cases during an outbreak of febrile illness in Espinal, Colombia. Occasional neurological complications and associated mortality were also first reported in humans during this time period [5]. Venezuelan equine...