West Nile virus Flashcards
What is the scientific name of this?
-Leading cause of domestically acquired arboviral disease
in the U.S.
-single-stranded RNA virus of the family Flaviviridae
West Nile virus
Incubation Period for WNV
2-6 days
but can range 2-14 days
How is WNV transmitted?
Primary the Culex mosquito
blood transfusion/organ donation
mother to child
WNV - Overview
(1) Outbreaks tend to occur between ____ months.
(2) ______ & ______correlate with increased WNV
transmission & infection.
—(a) The warmer & hotter it is, the more mosquitos will breed.
(3) Person-to-Person transmission is usually related to ________________.
(4) Mosquitoes become infected when they feed on infected ___; then spread virus to humans & other animals during bloodmeals.
(5) Horses & humans are considered ______ hosts.
1) mid-July and early September
2) Elevated temperatures and rainfall
3) blood transfusion and organ transplantation
4) birds
5) ‘dead-end’
What should be considered in any febrile patient or acute neurologic
illness with recent exposure to mosquitoes during the summer months in WNV endemic areas?
West Nile Virus…
__% of human WNV infections are subclinical or asymptomatic.
70-80
What issue
-Occurs between mid-July and early September with elevated temperatures & rainfall
An acute systemic febrile illness may be accompanied by:
1) Headache, weakness, myalgia, or arthralgia
2) Gastrointestinal symptoms
3) Transient maculopapular rash
WNV
What issue?
Clinically indistinguishable from viral meningitis due to other etiologies & typically presents with fever, headache, and nuchal rigidity.
WNV Meningitis
What issue?
A more severe clinical syndrome that usually manifests with fever and altered mental status, seizures, focal neurologic deficits, or movement disorders such as tremor or Parkinsonism.
WNV Encephalitis
True/False
There is no specific treatment for WNV disease, and no antiviral
treatment is available.
True
True/False
There is no specific treatment for WNV disease, and no antiviral
treatment is available.
True
first line management protocol for WNV
Vigorous supportive measures
When is MEDEVAC warranted for WNV
if there are signs of encephalitis, meningitis,
or paralysis.
True/False
WNV is preventable by vaccines
False
No WNV vaccines are licensed for use in humans
WNV – Lab Diagnosis
Diagnosis via identifying what
IgM in serum or CSF analysis
True/False
CBC is a reliable indicator of WNV disease
False
WNV – Lab Diagnosis
______ is used to detect WNV IgM antibody
ELISA
Due to the absence of a vaccine, prevention of WNV disease depends on:
(a) Community-level mosquito control programs to reduce vector
densities.
(b) Personal protective measures to decrease exposure to infected
mosquitoes
(c) Screening of blood and organ donors
Disposition
Non-neuroinvasive WNV:
Most patients with non-neuroinvasive WNV disease recover
completely; however, fatigue, malaise, and weakness can
linger for weeks or months.
Disposition
Neuroinvasive WNV
(a) Patients who recover from WNV encephalitis or
poliomyelitis often have residual ____________.
(b) Among patients with neuroinvasive disease, the overall case
fatality ratio is approximately ___%.
a) residual neurologic deficits
b) 10
