St. Louis encephalitis is caused by a virus. Mosquitoes are infected with this virus when they feed on birds. Infected mosquitoes can transmit the virus to humans and animals. St. Louis encephalitis is
spread from person to person.
Factors that may increase your chances of St. Louis encephalitis:
Living in or visiting the southern, central, or western US, especially during the
summer and fall
St. Louis encephalitis can result in a wide range of symptoms or produce no symptoms at all. The disease can be mild, severe, or even fatal.
Symptoms usually appear 5-15 days after the bite of an infected mosquito and may include:
EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.
This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.
To send comments or feedback to our Editorial Team regarding the content please email us at firstname.lastname@example.org. Our Health Library Support team will respond to your email request within 2 business days.