Eastern equine encephalomyelitis in Massachusetts; report of two cases, diagnosed serologically, with complete clinical recovery.

This research documents two cases of Eastern equine encephalomyelitis (EEE) identified in Massachusetts during the summer of 1955. Despite initial similarities to poliomyelitis, further testing confirmed both cases were examples of viral meningoencephalitis, which are extremely rare in the region.

Research Context

• The research was carried out in Massachusetts, a northeastern state in the US, during the peak of the poliomyelitis epidemic in the summer of 1955.
• The study centered around two patients showing symptoms of a neurological disease, initially suspected to be viral meningitis or encephalitis, which are rarely diagnosed in this region.

Case Observations

• The patients’ clinical picture was consistent with viral meningoencephalitis, a form of brain inflammation caused by a viral infection.
• The symptoms however differed from what is typical of poliomyelitis, a viral disease that can affect nerves and lead to partial or full paralysis, leading researchers to suspect another neurotropic virus was responsible.

Findings

• Following appropriate medical testing, serological diagnosis confirmed both patients were suffering from Eastern equine encephalomyelitis (EEE).
• EEE is a rare mosquito-borne virus, typically affecting horses and humans. It can cause severe neurological diseases and is often fatal in humans, hence, the significance of both patients making a full clinical recovery.
• This was a notable discovery at the time and marked the first time EEE had been identified in Massachusetts, highlighting the importance of careful differentiation between similar neurological diseases during widespread epidemics.