Official reprint from UpToDate®
www.uptodate.com ©2017 UpToDate, Inc. and/or its affiliates. All Rights Reserved.

Treatment and prevention of West Nile virus infection

Lyle R Petersen, MD, MPH
Section Editor
Martin S Hirsch, MD
Deputy Editor
Jennifer Mitty, MD, MPH


West Nile virus, a member of the Japanese encephalitis virus antigenic complex, can lead to a wide range of clinical symptoms from asymptomatic disease to severe meningitis and encephalitis.

Management and prevention of West Nile virus is discussed below. The clinical manifestations and epidemiology of the infection are discussed elsewhere. (See "Epidemiology and pathogenesis of West Nile virus infection" and "Clinical manifestations and diagnosis of West Nile virus infection".)


Treatment of WN virus infection is primarily supportive. The potential use of several different therapeutic agents has been described [1-11]. However, only one controlled study to evaluate specific therapies for WN virus infection has been completed [11]. Uncontrolled studies or case reports suggesting treatment efficacy should be cautiously interpreted, since the clinical course and outcomes with WN virus neuroinvasive disease are highly variable [1,2].

Agents that have been considered include:

Interferon — The rationale for the use of alfa interferon is based upon evidence of efficacy against WN virus in vitro and in animal models [3-5].

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information on subscription options, click below on the option that best describes you:

Subscribers log in here

Literature review current through: Nov 2017. | This topic last updated: Apr 04, 2016.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2017 UpToDate, Inc.
  1. Sejvar JJ, Haddad MB, Tierney BC, et al. Neurologic manifestations and outcome of West Nile virus infection. JAMA 2003; 290:511.
  2. Gea-Banacloche J, Johnson RT, Bagic A, et al. West Nile virus: pathogenesis and therapeutic options. Ann Intern Med 2004; 140:545.
  3. Morrey JD, Day CW, Julander JG, et al. Effect of interferon-alpha and interferon-inducers on West Nile virus in mouse and hamster animal models. Antivir Chem Chemother 2004; 15:101.
  4. Anderson JF, Rahal JJ. Efficacy of interferon alpha-2b and ribavirin against West Nile virus in vitro. Emerg Infect Dis 2002; 8:107.
  5. Sayao AL, Suchowersky O, Al-Khathaami A, et al. Calgary experience with West Nile virus neurological syndrome during the late summer of 2003. Can J Neurol Sci 2004; 31:194.
  6. Kalil AC, Devetten MP, Singh S, et al. Use of interferon-alpha in patients with West Nile encephalitis: report of 2 cases. Clin Infect Dis 2005; 40:764.
  7. Hrnicek MJ, Mailliard ME. Acute west nile virus in two patients receiving interferon and ribavirin for chronic hepatitis C. Am J Gastroenterol 2004; 99:957.
  8. Chowers MY, Lang R, Nassar F, et al. Clinical characteristics of the West Nile fever outbreak, Israel, 2000. Emerg Infect Dis 2001; 7:675.
  9. Planitzer CB, Modrof J, Kreil TR. West Nile virus neutralization by US plasma-derived immunoglobulin products. J Infect Dis 2007; 196:435.
  10. Agrawal AG, Petersen LR. Human immunoglobulin as a treatment for West Nile virus infection. J Infect Dis 2003; 188:1.
  11. Hart J Jr, Tillman G, Kraut MA, et al. West Nile virus neuroinvasive disease: neurological manifestations and prospective longitudinal outcomes. BMC Infect Dis 2014; 14:248.
  12. Petersen LR, Marfin AA. West Nile virus: a primer for the clinician. Ann Intern Med 2002; 137:173.
  13. O'Leary DR, Marfin AA, Montgomery SP, et al. The epidemic of West Nile virus in the United States, 2002. Vector Borne Zoonotic Dis 2004; 4:61.
  14. Sejvar JJ, Bode AV, Marfin AA, et al. West Nile virus-associated flaccid paralysis. Emerg Infect Dis 2005; 11:1021.
  15. Kleinschmidt-DeMasters BK, Marder BA, Levi ME, et al. Naturally acquired West Nile virus encephalomyelitis in transplant recipients: clinical, laboratory, diagnostic, and neuropathological features. Arch Neurol 2004; 61:1210.
  16. Centers for Disease Control and Prevention (CDC). West Nile virus infections in organ transplant recipients--New York and Pennsylvania, August-September, 2005. MMWR Morb Mortal Wkly Rep 2005; 54:1021.
  17. Klee AL, Maidin B, Edwin B, et al. Long-term prognosis for clinical West Nile virus infection. Emerg Infect Dis 2004; 10:1405.
  18. Sejvar JJ. The long-term outcomes of human West Nile virus infection. Clin Infect Dis 2007; 44:1617.
  19. Carson PJ, Konewko P, Wold KS, et al. Long-term clinical and neuropsychological outcomes of West Nile virus infection. Clin Infect Dis 2006; 43:723.
  20. Loeb M, Hanna S, Nicolle L, et al. Prognosis after West Nile virus infection. Ann Intern Med 2008; 149:232.
  21. Murray KO, Garcia MN, Rahbar MH, et al. Survival analysis, long-term outcomes, and percentage of recovery up to 8 years post-infection among the Houston West Nile virus cohort. PLoS One 2014; 9:e102953.
  22. Burton JM, Kern RZ, Halliday W, et al. Neurological manifestations of West Nile virus infection. Can J Neurol Sci 2004; 31:185.
  23. Marciniak C, Sorosky S, Hynes C. Acute flaccid paralysis associated with West Nile virus: motor and functional improvement in 4 patients. Arch Phys Med Rehabil 2004; 85:1933.
  24. Sejvar JJ, Bode AV, Marfin AA, et al. West Nile Virus-associated flaccid paralysis outcome. Emerg Infect Dis 2006; 12:514.
  25. Betensley AD, Jaffery SH, Collins H, et al. Bilateral diaphragmatic paralysis and related respiratory complications in a patient with West Nile virus infection. Thorax 2004; 59:268.
  26. Cao NJ, Ranganathan C, Kupsky WJ, Li J. Recovery and prognosticators of paralysis in West Nile virus infection. J Neurol Sci 2005; 236:73.
  27. Han LL, Popovici F, Alexander JP Jr, et al. Risk factors for West Nile virus infection and meningoencephalitis, Romania, 1996. J Infect Dis 1999; 179:230.
  28. Hadler JL, Patel D, Bradley K, et al. National capacity for surveillance, prevention, and control of West Nile virus and other arbovirus infections--United States, 2004 and 2012. MMWR Morb Mortal Wkly Rep 2014; 63:281.
  29. Gujral IB, Zielinski-Gutierrez EC, LeBailly A, Nasci R. Behavioral risks for West Nile virus disease, northern Colorado, 2003. Emerg Infect Dis 2007; 13:419.
  30. Carney RM, Husted S, Jean C, et al. Efficacy of aerial spraying of mosquito adulticide in reducing incidence of West Nile Virus, California, 2005. Emerg Infect Dis 2008; 14:747.
  31. Lothrop HD, Lothrop BB, Gomsi DE, Reisen WK. Intensive early season adulticide applications decrease arbovirus transmission throughout the Coachella Valley, Riverside County, California. Vector Borne Zoonotic Dis 2008; 8:475.
  32. Ruktanonchai DJ, Stonecipher S, Lindsey N, et al. Effect of aerial insecticide spraying on West Nile virus disease--north-central Texas, 2012. Am J Trop Med Hyg 2014; 91:240.
  33. Duprey Z, Rivers S, Luber G, et al. Community aerial mosquito control and naled exposure. J Am Mosq Control Assoc 2008; 24:42.
  34. Centers for Disease Control and Prevention (CDC). Human exposure to mosquito-control pesticides--Mississippi, North Carolina, and Virginia, 2002 and 2003. MMWR Morb Mortal Wkly Rep 2005; 54:529.
  35. Centers for Disease Control and Prevention (CDC). Surveillance for acute insecticide-related illness associated with mosquito-control efforts--nine states, 1999-2002. MMWR Morb Mortal Wkly Rep 2003; 52:629.
  36. Chung WM, Buseman CM, Joyner SN, et al. The 2012 West Nile encephalitis epidemic in Dallas, Texas. JAMA 2013; 310:297.
  37. Busch MP, Caglioti S, Robertson EF, et al. Screening the blood supply for West Nile virus RNA by nucleic acid amplification testing. N Engl J Med 2005; 353:460.
  38. Petersen LR, Epstein JS. Problem solved? West Nile virus and transfusion safety. N Engl J Med 2005; 353:516.
  39. Stramer SL, Fang CT, Foster GA, et al. West Nile virus among blood donors in the United States, 2003 and 2004. N Engl J Med 2005; 353:451.
  40. Montgomery SP, Brown JA, Kuehnert M, et al. Transfusion-associated transmission of West Nile virus, United States 2003 through 2005. Transfusion 2006; 46:2038.
  41. McDonald WF, Huleatt JW, Foellmer HG, et al. A West Nile virus recombinant protein vaccine that coactivates innate and adaptive immunity. J Infect Dis 2007; 195:1607.
  42. Pletnev AG, Claire MS, Elkins R, et al. Molecularly engineered live-attenuated chimeric West Nile/dengue virus vaccines protect rhesus monkeys from West Nile virus. Virology 2003; 314:190.
  43. Qiao M, Ashok M, Bernard KA, et al. Induction of sterilizing immunity against West Nile Virus (WNV), by immunization with WNV-like particles produced in insect cells. J Infect Dis 2004; 190:2104.
  44. Monath TP, Liu J, Kanesa-Thasan N, et al. A live, attenuated recombinant West Nile virus vaccine. Proc Natl Acad Sci U S A 2006; 103:6694.
  45. Biedenbender R, Bevilacqua J, Gregg AM, et al. Phase II, randomized, double-blind, placebo-controlled, multicenter study to investigate the immunogenicity and safety of a West Nile virus vaccine in healthy adults. J Infect Dis 2011; 203:75.
  46. Dayan GH, Bevilacqua J, Coleman D, et al. Phase II, dose ranging study of the safety and immunogenicity of single dose West Nile vaccine in healthy adults ≥ 50 years of age. Vaccine 2012; 30:6656.
  47. Martin JE, Pierson TC, Hubka S, et al. A West Nile virus DNA vaccine induces neutralizing antibody in healthy adults during a phase 1 clinical trial. J Infect Dis 2007; 196:1732.
  48. U.S. Centers for Disease Control. Interim Guidelines for the Evaluation of Infants Born to Mothers Infected With West Nile Virus During Pregnancy. www.cdc.gov/ncidod/dvbid/westnile/congenitalinterimguidelines.htm (Accessed on March 07, 2005).
  49. Centers for Disease Control and Prevention (CDC). Interim guidelines for the evaluation of infants born to mothers infected with West Nile virus during pregnancy. MMWR Morb Mortal Wkly Rep 2004; 53:154.