Japanese Encephalitis Clinical Presentation

  • Author: Asim A Jani, MD, MPH, FACP; Chief Editor: Burke A Cunha, MD   more...
 
Updated: Jan 6, 2012
 

History

Individuals with Japanese encephalitis virus (JEV) infection have a history of mosquito exposure in an endemic area. The incubation period averages 6-8 days, with a range of 4-15 days. The prodromal period is characterized by fever, headache, nausea, diarrhea, vomiting, and myalgia, which may last for several days.

Altered mental status follows, which can range from mild confusion to agitation to overt coma. Seizures develop in 66% of infected persons, most often in children, while headache and meningismus are more common in adults.

Tremor or other involuntary movements are common, and mutism has been reported as a presenting symptom. A syndrome of acute flaccid paralysis has also been described, attributed to the involvement of spinal anterior cells resulting in a poliomyelitis like presentation. Fevers disappear by the second week, and choreoathetosis or extrapyramidal symptoms develop as the other neurologic symptoms disappear.

Next

Physical Examination

Neurologic signs of Japanese encephalitis vary.

Generalized weakness, hypertonia, and hyperreflexia (including the presence of pathologic reflexes) are common.

Papilledema develops in less than 10% of patients, and 33% have cranial nerve findings (eg, disconjugate gaze, cranial nerve palsies).

Parkinsonlike extrapyramidal signs are common, including masklike facies, tremor, rigidity, and choreoathetoid movements.

In one study, central hyperpneic breathing and extrapyramidal signs were the best clinical predictors of infection (41% sensitive, 81% specific).[7]

Previous
Proceed to Differential Diagnoses
 
 
Contributor Information and Disclosures
Author

Asim A Jani, MD, MPH, FACP  Clinician-Educator and Epidemiologist, Consultant and Senior Physician, Florida Department of Health; Diplomate, Infectious Diseases, Internal Medicine and Preventive Medicine

Asim A Jani, MD, MPH, FACP is a member of the following medical societies: American Association of Public Health Physicians, American College of Physicians, American College of Preventive Medicine, American Medical Association, American Public Health Association, and Infectious Diseases Society of America

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, and Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Additional Contributors

Joseph F John Jr, MD, FACP, FIDSA, FSHEA Clinical Professor of Medicine, Molecular Genetics and Microbiology, Medical University of South Carolina College of Medicine; Associate Chief of Staff for Education, Ralph H Johnson Veterans Affairs Medical Center

Disclosure: Nothing to disclose.

Alexander J Kallen, MD Instructor of Medicine, Department of Internal Medicine, Division of Outcomes Research, Dartmouth Medical School, Veterans Affairs Medical Center of White River Junction, VT

Alexander J Kallen, MD is a member of the following medical societies: American College of Physicians, American Medical Association, American Society for Microbiology, California Medical Association, and Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Klaus-Dieter Lessnau, MD, FCCP Clinical Associate Professor of Medicine, New York University School of Medicine; Medical Director, Pulmonary Physiology Laboratory; Director of Research in Pulmonary Medicine, Department of Medicine, Section of Pulmonary Medicine, Lenox Hill Hospital

Klaus-Dieter Lessnau, MD, FCCP is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, American Medical Association, American Thoracic Society, and Society of Critical Care Medicine

Disclosure: Sepracor None None

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

  1. Vazquez A, Jimenez-Clavero M, Franco L, et al. Usutu virus: potential risk of human disease in Europe. Euro Surveill. Aug 4 2011;16(31):[Medline].

  2. Ravi V, Taly AB, Shankar SK, Shenoy PK, Desai A, Nagaraja D, et al. Association of Japanese encephalitis virus infection with Guillain-Barré syndrome in endemic areas of south India. Acta Neurol Scand. Jul 1994;90(1):67-72. [Medline].

  3. Kuwayama M, Ito M, Takao S, Shimazu Y, Fukuda S, Miyazaki K, et al. Japanese encephalitis virus in meningitis patients, Japan. Emerg Infect Dis. Mar 2005;11(3):471-3. [Medline].

  4. Unni SK, Ružek D, Chhatbar C, Mishra R, Johri MK, Singh SK. Japanese encephalitis virus: from genome to infectome. Microbes Infect. Apr 2011;13(4):312-21. [Medline].

  5. Hanna JN, Ritchie SA, Phillips DA, Shield J, Bailey MC, Mackenzie JS, et al. An outbreak of Japanese encephalitis in the Torres Strait, Australia, 1995. Med J Aust. Sep 2 1996;165(5):256-60. [Medline].

  6. Kumar R, Tripathi P, Singh S, Bannerji G. Clinical features in children hospitalized during the 2005 epidemic of Japanese encephalitis in Uttar Pradesh, India. Clin Infect Dis. Jul 15 2006;43(2):123-31. [Medline].

  7. Richman DD, Whitley RJ, Hayden FG. Clinical Virology. New York, NY: Churchill Livingstone; 1997.

  8. Solomon T, Thao LT, Dung NM, Kneen R, Hung NT, Nisalak A, et al. Rapid diagnosis of Japanese encephalitis by using an immunoglobulin M dot enzyme immunoassay. J Clin Microbiol. Jul 1998;36(7):2030-4. [Medline]. [Full Text].

  9. Hoke CH Jr, Vaughn DW, Nisalak A, Intralawan P, Poolsuppasit S, Jongsawas V, et al. Effect of high-dose dexamethasone on the outcome of acute encephalitis due to Japanese encephalitis virus. J Infect Dis. Apr 1992;165(4):631-7. [Medline].

  10. Harinasuta C, Nimmanitya S, Titsyakorn U. The effect of interferon-alpha A on two cases of Japanese encephalitis in Thailand. Southeast Asian J Trop Med Public Health. Jun 1985;16(2):332-6. [Medline].

  11. Solomon T, Dung NM, Wills B, Kneen R, Gainsborough M, Diet TV, et al. Interferon alfa-2a in Japanese encephalitis: a randomised double-blind placebo-controlled trial. Lancet. Mar 8 2003;361(9360):821-6. [Medline].

  12. Lee E, Pavy M, Young N, Freeman C, Lobigs M. Antiviral effect of the heparan sulfate mimetic, PI-88, against dengue and encephalitic flaviviruses. Antiviral Res. Jan 2006;69(1):31-8. [Medline].

  13. Saxena SK, Mathur A, Srivastava RC. Inhibition of Japanese encephalitis virus infection by diethyldithiocarbamate is independent of its antioxidant potential. Antivir Chem Chemother. Mar 2003;14(2):91-8. [Medline].

  14. Swarup V, Ghosh J, Mishra MK, Basu A. Novel strategy for treatment of Japanese encephalitis using arctigenin, a plant lignan. J Antimicrob Chemother. Mar 2008;61(3):679-88. [Medline].

  15. Yang SE, Pan MJ, Tseng HF, Liau MY. The efficacy of mouse-brain inactivated Nakayama strain Japanese encephalitis vaccine--results from 30 years experience in Taiwan. Vaccine. Mar 24 2006;24(14):2669-73. [Medline].

  16. Harakuni T, Kohama H, Tadano M, et al. Mucosal vaccination approach against mosquito-borne Japanese encephalitis virus. Jpn J Infect Dis. Jan 2009;62(1):37-45. [Medline].

  17. Yang DK, Kweon CH, Kim BH, Hwang IJ, Kang MI, So BJ, et al. The seroprevalence of Japanese encephalitis virus in goats raised in Korea. J Vet Sci. Jun 2007;8(2):197-9. [Medline]. [Full Text].

  18. Solomon T, Thao TT, Lewthwaite P, Ooi MH, Kneen R, Dung NM, et al. A cohort study to assess the new WHO Japanese encephalitis surveillance standards. Bull World Health Organ. Mar 2008;86(3):178-86. [Medline]. [Full Text].

  19. Schiøler KL, Samuel M, Wai KL. Vaccines for preventing Japanese encephalitis. Cochrane Database Syst Rev. Jul 18 2007;CD004263. [Medline].

  20. Thongtan T, Cheepsunthorn P, Chaiworakul V, Rattanarungsan C, Wikan N, Smith DR. Highly permissive infection of microglial cells by Japanese encephalitis virus: a possible role as a viral reservoir. Microbes Infect. Jan 2010;12(1):37-45. [Medline].

 
Previous
Next
 
Geographic distribution of Japanese encephalitis. Courtesy of the CDC.
Japanese encephalitis, 2006. Courtesy of the WHO.
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2012 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.