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St. Louis Encephalitis Clinical Presentation

  • Author: Charurut Somboonwit, MD, FACP; Chief Editor: Burke A Cunha, MD  more...
 
Updated: Apr 16, 2015
 

History and Physical Examination

After an incubation period of 4-21 days, St. Louis encephalitis virus (SLEV) infection can cause mild febrile illness, aseptic meningitis, or encephalitis. A prodrome of malaise and fever accompanied by cough and sore throat characterizes the onset of St. Louis encephalitis. Headache, nausea, vomiting, confusion, disorientation, irritability, tremors, and, occasionally, convulsions follow.

Several days after the onset of infection, the patient will defervesce, with gradual neurologic improvement over several days. Chronic infection does not occur, and relapsing infection has not been reported.

Most patients with SLEV infection develop a significant fever. Meningismus may or not be present. Photophobia is seldom present.

The neurologic examination findings are usually normal. Five percent of patients with SLEV infection present with deep coma, and 25% develop cranial nerve palsies. Fewer exhibit ataxia. Seizures are unusual and occur more frequently in children.[9]

 
 
Contributor Information and Disclosures
Author

Charurut Somboonwit, MD, FACP Associate Professor of Internal Medicine, Division of Infectious Disease and International Medicine, University of South Florida College of Medicine; Clinical Research and Communicable Diseases Director, USF Health and Hillsborough Health Department

Charurut Somboonwit, MD, FACP is a member of the following medical societies: American College of Physicians, American Medical Association, Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Coauthor(s)

Fariba M Donovan, MD, PhD Intercoastal Medical Group

Fariba M Donovan, MD, PhD is a member of the following medical societies: American College of Physicians, American Society for Microbiology, Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Joseph T Katta, DO Fellow in Infectious Disease and International Medicine, University of South Florida College of Medicine

Joseph T Katta, DO is a member of the following medical societies: American College of Physicians, American Osteopathic Association

Disclosure: Nothing to disclose.

Chief Editor

Burke A Cunha, MD Professor of Medicine, State University of New York School of Medicine at Stony Brook; Chief, Infectious Disease Division, Winthrop-University Hospital

Burke A Cunha, MD is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Acknowledgements

John L Brusch, MD, FACP Assistant Professor of Medicine, Harvard Medical School; Consulting Staff, Department of Medicine and Infectious Disease Service, Cambridge Health Alliance

John L Brusch, MD, FACP is a member of the following medical societies: American College of Physicians and Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Eduardo Gotuzzo, MD Adjunct Professor, Department of Medicine, University of Alabama School of Medicine

Disclosure: Nothing to disclose.

Eleftherios Mylonakis, MD Clinical and Research Fellow, Department of Internal Medicine, Division of Infectious Diseases, Massachusetts General Hospital

Eleftherios Mylonakis, MD is a member of the following medical societies: American Association for the Advancement of Science, American College of Physicians, American Society for Microbiology, and Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Mary D Nettleman, MD, MS, MACP Professor and Chair, Department of Medicine, Michigan State University College of Human Medicine

Mary D Nettleman, MD, MS, MACP is a member of the following medical societies: American College of Physicians, Association of Professors of Medicine, Central Society for Clinical Research, Infectious Diseases Society of America, and Society of General Internal Medicine

Disclosure: Nothing to disclose.

Norvin Perez, MD Medical Director, Juneau Urgent and Family Care

Norvin Perez, MD is a member of the following medical societies: American College of Emergency Physicians and American Medical Association

Disclosure: Nothing to disclose.

Emad Soliman, MD, MSc Consulting Staff, Department of Neurology, St John's Riverside Hospital

Emad Soliman, MD, MSc is a member of the following medical societies: American Academy of Neurology and American Medical Association

Disclosure: Nothing to disclose.

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

References
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  7. Day JF. Predicting St. Louis encephalitis virus epidemics: lessons from recent, and not so recent, outbreaks. Annu Rev Entomol. 2001. 46:111-38. [Medline].

  8. White MG, Carter NW, Rector FC, et al. Pathophysiology of epidemic St. Louis encephalitis. I. Inappropriate secretion of antidiuretic hormone. II. Pituitary-adrenal function. 3. Cerebral blood flow and metabolism. Ann Intern Med. 1969 Oct. 71(4):691-702. [Medline].

  9. Sejvar JJ, Bode AV, Curiel M, Marfin AA. Post-infectious encephalomyelitis associated with St. Louis encephalitis virus infection. Neurology. 2004 Nov 9. 63(9):1719-21. [Medline].

  10. Rahal JJ, Anderson J, Rosenberg C, Reagan T, Thompson LL. Effect of interferon-alpha2b therapy on St. Louis viral meningoencephalitis: clinical and laboratory results of a pilot study. J Infect Dis. 2004 Sep 15. 190(6):1084-7. [Medline].

 
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