equine encephalitis

noun

variants or less commonly equine encephalomyelitis
: any of three viral diseases chiefly of equines and humans in various parts of North and South America that are transmitted especially by mosquitoes, are characterized in humans by flu-like symptoms which often progress to encephalitis and sometimes to coma and death, and are caused by three togaviruses (genus Alphavirus)
a
: one (Alphavirus eastern) that occurs in the eastern U.S. and Canada

called also eastern equine encephalitis, eastern equine encephalomyelitis, triple E

b
: one (Alphavirus western) that occurs in the western U.S. and Canada

called also western equine encephalitis, western equine encephalomyelitis

c
: one (Alphavirus venezuelan) that occurs from northern South America to Mexico

called also Venezuelan equine encephalitis, Venezuelan equine encephalomyelitis

Examples of equine encephalitis in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Navarro has dedicated 30 years to studying arboviruses such as dengue, equine encephalitis, Mayaro, and, since 2016, Oropouche. Geraldine Castro, WIRED, 20 Dec. 2024 New York has reported the state’s first death from Eastern equine encephalitis (EEE), a disease that spreads through bites from mosquitoes. Melissa Rudy, Fox News, 25 Sep. 2024 Michigan’s first case this year of Eastern equine encephalitis was detected in a horse in Van Buren County, the state announced. Gina Kaufman, Detroit Free Press, 9 Aug. 2024 Information about Eastern equine encephalitis virus can be found here. John Tufts, The Indianapolis Star, 26 Aug. 2023 See All Example Sentences for equine encephalitis

Word History

First Known Use

1910, in the meaning defined above

Time Traveler
The first known use of equine encephalitis was in 1910

Browse Nearby Words

Cite this Entry

“Equine encephalitis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/equine%20encephalitis. Accessed 10 Nov. 2025.

Medical Definition

equine encephalitis

noun
: any of three viral diseases chiefly of equines and humans in various parts of North and South America that are transmitted especially by mosquitoes, are characterized in humans by flu-like symptoms which often progress to encephalitis and sometimes to coma and death, and are caused by three togaviruses of the genus Alphavirus:
a
: one (Alphavirus eastern) that occurs in the eastern U.S. and Canada

called also eastern equine encephalitis, eastern equine encephalomyelitis

b
: one (Alphavirus western) that occurs in the western U.S. and Canada

called also western equine encephalitis, western equine encephalomyelitis

c
: one (Alphavirus venezuelan) that occurs from northern South America to Mexico

called also Venezuelan equine encephalitis, Venezuelan equine encephalomyelitis

More from Merriam-Webster on equine encephalitis

Last Updated: - Definition revised
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