Morning Report 10/8/15 West Nile Virus

A special thanks to the ID service for joining us today!

Clinical Pearls: 

  • Kernig and Brudinski’s sign (thanks to Dan for demonstrating!)
  • PRES: Posterior Reversible Encephalopathy Syndrome presents as headaches, confusion, seizures, and visual loss often in the setting of elevated blood pressure. Thought to be secondary to problems in cerebral autoregulation. Associated with immunosuppression, renal failure, eclampsia, hypertension, lupus.
  • Obtain a CT scan prior to an LP to evaluate for mass lesions that can cause brain herniation in the following patients:
    • Age >60
    • Immunocompromised
    • History of CNS disease
    • Seizure within one week of presentation
  • Empiric treatment for suspected bacterial meningitis includes Ceftriaxone (2gm IV q12 for CNS penetration), Vancomycin (resistant Strep pneumonia), and Ampicillin (immunocompromised and elderly patients for Listeria coverage, use Bactrim for penicillin allergies)
  • Start IV Acyclovir to cover possible HSV meningitis/encephalitis. HSV-1 is associated with encephalitis while HSV-2 can cause recurrent aseptic meningitis (Mollaret’s meningitis).
  • West Nile Virus
    • Flavivirus which was first detected in the US in 1999, over 500 cases in California last year
    • Asymptomatic in 80% of patients, symptomatic patients present with West Nile Fever (20%) or West Nile Neuroinvasive Disease (<1%)
    • Can manifest with acute flaccid paralysis, extrapyramidal signs
    • Detection of West Nile Virus IgM antibody in the CSF of symptomatic patients is diagnostic of West Nile Neuroinvasive Disease
    • Serologic cross-reactivity with other flaviviruses can cause false-positives (for example recent Yellow Fever vaccination or dengue infection)
    • Treatment of WNV is supportive 

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