Notifiable condition. It is the most deadly encephalitic arbovirus in North America, with a case fatality rate of 30% to 50%.
Occurs mainly in North America, around the eastern seaboard and Gulf coast states, and is transmitted by mosquitoes.
Diagnosis is based on clinical presentation and geographical clues. Confirmation of diagnosis is via serological testing.
There is no specific treatment; supportive care with management of specific symptoms is recommended.
Eastern equine encephalitis virus (EEEV) is a positive-sense single-stranded RNA virus (family: Togaviridae; genus: Alphavirus) transmitted by mosquitoes.
In humans infected with EEEV, the incubation period ranges from 4 to 10 days, and duration of acute illness is typically days to weeks depending on severity.
Humans infected with EEEV may be asymptomatic, or they may develop symptoms that resemble influenza or dengue fever (e.g., fever, malaise, headache, nausea) with or without neuroinvasive symptoms (e.g., altered mental status, seizures). The mortality rate for humans with neuroinvasive disease is approximately 30% to 50%.
History and exam
- neck stiffness (nuchal rigidity)
- focal weakness (decreased motor function)
- abdominal pain
- altered mental status
- cranial nerve palsy
- cerebral oedema
- intracranial hypertension
- aseptic meningitis
- haemophagocytic lymphohistiocytosis
Division of Infectious Disease and Global Medicine
University of Florida
AV is funded by the National Institute of Allergy and Infectious Diseases (NIAID) for work on host susceptibility and emerging alphaviruses (2016-2021); however, the funding supports new insights in the field only, it does not directly impact any articles produced. AV is also the author of a reference cited in this monograph.
Infectious Diseases Consultant
Naples Community Hospital
MGM declares that he has no competing interests.
US Naval Medical Research Unit 6 (NAMRU-6)
SV declares that he has no competing interests.
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