Genetic Diversity and Evolutionary Dynamics of Eastern Equine Encephalitis Viruses (EEEV)

Eastern equine encephalitis virus (EEEV) and Madariaga virus (MADV) are mosquito-borne alphavirus (family Togaviridae) of significant public and veterinary health importance throughout the Americas. It has a single-stranded positive sense RNA genome of about 11,700 nt in length. EEEV causes a very debilitating disease in humans with case-fatality rates ranging between 50 and 75%; and for equids, rates can be as high as 80%. It is currently classified as a select agent on the NIAID category B list of priority pathogens, and was being developed for use as a potential bioweapon during the cold war. 

Despite hundreds of isolations and the significant public and veterinary health problem this virus poses, the majority of EEEV genetic studies primarily involved only partial gene sequences of the structural or non-structural genes and only few complete genomes have been determined and deposited on GenBank to date. Recently, to fill this gap, we have submitted ~100 EEEV and MADV full genomes sequences from North America. The proposed project aims to sequence complete genomes for another ~300 EEEV strains isolated between 1971 and 2012 from mosquitoes and horses and will provide a broad characterization of geographical differences, virus movement, vector-host transmission dynamics, and evolutionary rates between specific locations.


Research reported in this publication was supported by the National Institute Of Allergy And Infectious Diseases of the National Institutes of Health under Award Number U19AI110819. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Principal Investigator


Laura D. Kramer, PhD
Griffin Lab


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