West Nile Virus. Syndrome. (Family: Flaviviridae) Severe Manifestations (Typically >50 years of age) NEUROLOGICAL (Meningoencephalitis >Meningitis)

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1 Severe Manifestations (Typically >50 years of age) Syndrome NEUROLOGICAL (Meningoencephalitis >Meningitis) CSF WBC Protein Glucose-WNL Confusion Change in Sensorium Stupor Seizures Ataxia Cranial Nerve Dysfunction Myelitis Extrapyramidal Findings Rash: Maculopapular/ Morbilliform (neck, trunk, arms, legs) Severe Headache Eye Pain (Optic Neuritis) Conjunctival Injection Pharyngitis Nuchal Rigidity Cough Dyspnea Classic Symptoms SGOT/SGPT Hepatomegaly Anemia Lymphopenia Thrombocytopenia Arthralgia Abdominal Pain Nausea Vomiting Splenomegaly Diarrhea Muscle Weakness -->Paralysis Abnormal Reflexes Fever (sudden onset), Myalgias, Chills, Fatigue, Lymphadenopathy (especially submental) 1

2 Method of Dissemination: Mosquito bite Vector: Mosquitoes (primarily of the Culex species) Reservoir Host: Wild birds primarily (e.g. American crows) Incidental Hosts: Humans, horses, cats, bats, chipmunks, skunks, rabbits, dogs, squirrels Occurrence: Summer-Early Fall (May become Perennial) Early Warning Sign: Dead Birds (Report findings to local health dept.; testing must be done within 48h of death) Incubation Period: 3-14 days Morbidity: <1% of those infected develop severe illness. Most are asymptomatic. Nonspecific flu-like symptoms develop in 20% (lasts 3-6 days). Lethality: 3-15% of those who develop severe illness. Mortality greatest in the elderly and immunocompromised.? NO Transmission Transmission Blood? Organ Transplants? Diagnostic Samples: Serum, CSF (IgG ELISA/IgM antibody-capture ELISA) Imaging Studies: Brain CT-Negative Brain MRI: 1/3 with Leptomeningeal/Periventricular Enhancement Differential Diagnosis: Guillain-Barre Syndrome, Subacute Bacterial Endocarditis, Rocky Mountain Spotted Fever, Herpesvirus Type 1 Encephalitis (Only Treatable Viral Encephalitis), Legionnaires' Disease, Other Viral Encephalitides, Aseptic Meningitis. 2

3 Therapy 1. Supportive 2. Ribavirin (high dose); Interferon-α2b: in vitro studies 3. Immunoglobulin (containing high titers of WNV Antibodies): 1 report Victim Isolation: NO Health Care Provider Precautions: STANDARD Preventative Measures 1. Stay indoors at dawn, dusk, and early evening. 2. If outdoors, wear long-sleeve shirts and long pants. 3. Spray clothes and bare skin areas with up to 50% DEET (higher concentrations not needed and potentially harmful) (10% DEET for children > 2 mos. of age). 3

4 I.P Asymptomatic Flu-like Symptoms } Majority of Patients 35 Days Severity Minority of Patients Meningoencephalitis Prolonged/Permanent Sequelae Death 4

5 References 1. CDC West Nile Virus Homepage: Accessed 9/4/ Edison M, Kramer L, Stone W, et al. Dead Bird Surveillance as an Early Warning System for West Nile Virus. Accessed 8/27/01 3. Chowers MY, Lang R, Nassar F, et al. Clinical Characteristics of the West Nile Fever outbreak, Israel, Accessed 8/27/ Weiss D, Carr D, Kellachan J, et al. Clinical Findings of the West Nile Infection in Hospitalized Patients, New York and New Jersey, Accessed 8/27/ Weinberger M, Pitlik SD, Grandacu D, et al. West Nile Fever Outbreak, Israel, 2000: Epidemiologic Aspects. Accessed 8/27/ Shimoni Z, Niven MJ, Pitlik S, et al. Treatment of the West Nile Virus Encephalitis with Intravenous Immunoglobulin. Accessed 8/27/ Giladi M, Metzkor-Cotter E, Martin DA, et al. West Nile Encephalitis in Israel, 1999: The New York Connection. Accessed 8/27/01 8. Eidson M, Komar N, Sorhage F, et al. Crow deaths as Sentinel Surveillance Systems for West Nile Virus in the Northeastern United States, Accessed 8/27/ Petersen LR, Roehrig JT. West Nile Virus: A Reemerging Global Pathogen. Accessed 8/27/ Cunha BA. West Nile Encephalitis. Accessed 9/4/ Peterson LR, Marfin AA. West Nile Virus: A Primer for the Clinician. Ann Intern Med. 2002; 137: CDC West Nile Virus Infection: Information for Clinicians. Accessed 9/5/ CDC Health Advisory. Possible West Nile Virus Infection in Organ Transplant Recipients-Information for Clinicians. Sept. 4, CDC Health Advisory. West Nile Virus Infection Information for Clinicians. Aug. 21,