Viral Infections: West Nile Virus Flashcards
What are the two very different presentations of West Nile Virus?
> Mild / Self-limited
> Severe neuroinvasive disease associated with long-term neurologic sequelae
To which genus does West Nile Virus belong?
Arbovirus (arthropod-borne) of flavivirus group
Distribution of West Nile Virus
Old World distribution > Africa > Middle East > Europe > Southeast asia > Australia
What is the mode of transmission of West Nile Virus?
Mosquitoes to birds and mammals
What is the major reservoir of West Nile Virus?
Birds which have prolonged viremia
What is the incidental hosts of West Nile Virus? How do they become one?
> Humans
> Transmitted from mosquito bites in most cases
Human to human (blood transfusion, organ transplant, breastfeeding, transplacental)
Where does the West Nile Virus replicate in?
> Replicates in skin dendritic cells –> Lymph nodes –> Hematogenous spreading
> Some enter the CNS by breaching the BBB and infect neurons
What chemokine receptor contributes to CNS resistance to West Nile Virus infection?
CCR5
West Nile Virus is mostly symptomatic or asymptomatic?
Asymptomatic
What can be done to diagnose West Nile Virus?
> Serology
> Viral culture
> PCR
What are rare complications of West Nile Virus infection?
> Hepatitis
> Myocarditis
> Pancreatitis
There is CNS complications in ___ in 150 people with West Nile Virus
1 in 150
What are the CNS complications seen in West Nile Virus infection?
> Meningitis
> Encephalitis
> Meningoencephalitis
What kind of rash can be seen in West Nile Virus?
Maculopapular rash
20% of those with West Nile Virus infection present with what?
> Fever
> Headache
> Myalgia
> Fatigue
> Anorexia
> Nausea
