Eastern equine encephalitis virus infection

Eastern equine encephalitis virus 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. It is a notifiable condition.

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.[1]Public Health Service; Centers for Disease Control and Prevention; National Institutes of Health. Biosafety in microbiological and biomedical laboratories 5th edition. December 2009 [internet publication]. https://www.cdc.gov/labs/BMBL.html

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%.[2]Silverman MA, Misasi J, Smole S, et al. Eastern equine encephalitis in children, Massachusetts and New Hampshire, USA, 1970-2010. Emerg Infect Dis. 2013 Feb;19(2):194-201. http://wwwnc.cdc.gov/eid/article/19/2/12-0039_article http://www.ncbi.nlm.nih.gov/pubmed/23343480?tool=bestpractice.com