How Is the Disease Transmitted to Humans?
The St. Louis
encephalitis virus has a complex life cycle involving common birds (e.g., sparrows, finches, blue jays, robins, doves) and specific types of
Culex mosquitoes that feed mainly on birds.
Humans and other mammals are not an important part of the life cycle of the St. Louis encephalitis virus. Sometimes, however, people who live in or visit an area where the virus lives can be infected by the bite of an infected mosquito. After infection, the virus invades the central nervous system, including the spinal cord and brain.
Symptoms of St. Louis Encephalitis
In its more severe form, the disease can cause convulsions and death.
Who Is at Risk for St. Louis Encephalitis?
Anyone can get St. Louis encephalitis, but some people are at increased risk of severe disease. These groups of people include:
- Elderly people
- People living in crowded, low-income areas
- People who work outside or participate in outdoor recreational activities in areas where the disease is common.
There is no specific treatment for St. Louis encephalitis. Antibiotics are not effective against viruses, and no effective
antiviral drugs have been discovered. Care for patients with this condition focuses on treatment of symptoms and associated complications.