Treatment & Prevention


There is no specific treatment for St. Louis encephalitis (SLE); clinical management is supportive. Patients with severe meningeal symptoms often require pain control for headaches and antiemetic therapy and rehydration for associated nausea and vomiting. Patients with encephalitis require close monitoring for the development of elevated intracranial pressure, seizures, and inability to protect their airway.


No SLE virus vaccines are available for use in humans. In the absence of a vaccine, prevention of SLE virus infection depends on personal protective measures to decrease exposure to infected mosquitoes. This includes using insect repellent, wearing long-sleeved shirts and pants, treating clothing and gear with 0.5% permethrin, and taking steps to control mosquitoes indoors and outdoors. More information about preventing mosquito bites can be found here.

SLE virus can be transmitted through blood transfusions. People recently diagnosed with SLE virus infections should not donate blood for 120 days (4 months) after their illness. SLE virus infections temporally associated with blood transfusion should be reported promptly to the appropriate state health department.