Eastern equine encephalomyelitis virus (EEE), commonly calle sleeping sickness or "Triple E", is a zoonotic alphavirus and arbovirus present in North, Central and South America and the Caribbean. EEE was first recognised in Massachusetts, USA in 1831 when 75 horses died of encephalitic illness. Epizootics in horses have continued to occur regularly in the United States. EEE is found today in the eastern part of the country and is often associated with coastal plains.