| Description: | This negatively-stained transmission electron micrograph (TEM) revealed the presence of numerous St. Louis encephalitis virions that were contained within a mosquito salivary gland tissue sample. St. Louis encephalitis (SLE) virus is a member of the genus Flavivirus, family Flaviviridae. Other similar diseases are West Nile virus (WNV), eastern equine encephalitis (EEE), western equine encephalitis (WEE), and La Crosse encephalitis. What is the basic St. Louis encephalitis virus transmission cycle? Mosquitoes (primarily the Culex species) become infected by feeding on birds infected with the St. Louis encephalitis virus. Infected mosquitoes then transmit the St. Louis encephalitis virus to humans and animals during the feeding process. The SLE virus grows both in the infected mosquito and the infected bird, but does not make either one sick. What type of illness does St. Louis encephalitis virus cause? Many persons infected with St. Louis encephalitis virus have no apparent illness. People with mild illness often have only a headache and fever. More severe infection is marked by headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, occasional convulsions (especially in infants) and spastic (but rarely flaccid) paralysis. |
