St Louis Encephalitis Virus

Infection with Saint Louis Encephalitis virus rarely results in severe symptoms. It is closely related to West Nile virus and distinguishing between the viruses requires advanced diagnostic tests.

Infected mosquitoes pass the virus to birds when they take a blood meal.

Mosquitoes can transmit St. Louis encephalitis virus to humans too. Few infected people develop symptoms, but serious disease can occur.  The health risk is higher for elderly and immune compromised persons. Saint Louis Encephalitis was detected in mosquito samples and a sentinel chicken sample within the District in 2023, which previously hadn't been found since 1972.

Severe Symptoms:

  • Headache
  • High fever
  • Neck stiffness
  • Stupor
  • Disorientation
  • Coma
  • Tremors
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