CLINICAL DESCRIPTION

Eastern equine encephalitis is a rare but serious disease caused by the Eastern equine encephalitis (EEE) virus. EEE is found mainly along the eastern seaboard and the Gulf coast of the United States. The salt marsh mosquito is the principal human vector of the virus in New Jersey. Infection with EEE virus can cause a range of illnesses. Most people infected with the virus have no symptoms; others get only a mild flu-like illness with fever, headache, and a sore throat. In rare cases, infection of the central nervous system occurs, causing sudden fever, muscle pains and a headache of increasing severity, often quickly followed by seizures and coma. In these rare instances, about one third of the patients die from the disease. Of those who survive, many suffer permanent brain damage.

CASE CLASSIFICATION

1. CONFIRMED

   A clinically compatible case AND

   • Fourfold or greater change in serum antibody titer,
   • Isolation of virus from or demonstration of viral antigen or genomic sequences in tissue, blood, cerebrospinal fluid (CSF), or other body fluid, or
   • Specific immunoglobulin M (IgM) antibody by enzyme immunoassay (EIA) antibody captured in CSF or serum. Serum IgM antibodies alone should be confirmed by demonstration of immunoglobulin G antibodies by another serologic assay (e.g., neutralization or hemagglutination inhibition).
     
     

   
   

2. PROBABLE

   A clinically compatible case occurring during a period when arboviral transmission is likely, and with serum IgM antibodies detected by antibody-capture EIA but without confirmatory test to demonstrate Eastern Equine virus-specific serum neutralizing antibodies in the same or later specimen.

   
   

3. POSSIBLE
   
   Not used.