West Nile Virus

WHAT IS IT?

West Nile virus (WNV) is a febrile viral illness.

WHAT CAUSES IT?

The West Nile virus is a single-straneded RNA flavivirus transmitted by the female mosquito (Culex)

WHY IS IT A PROBLEM?

Infection with this virus can cause encephalitis, meningitis, and/or flaccid paralysis.

The West Nile virus is carried by mosquitos and transmitted by insect bites (source)
The West Nile virus is carried by mosquitos and transmitted by insect bites (source)
WHAT MAKES US SUSPECT IT?

Risk factors

 

Initial Presentation

Common Chief Complaints:

  • Leg weakness
  • Difficulty walking
  • Rash

History Of Present Illness

Recent mosquito bite will likely be present (even if not found/remembered by the patient).

Physical Exam Findings

Vital signs often will reveal a fever.

Dermatological findings can include a morbilliform rash on her trunk/arms.

Neurological exam can reveal flaccid paralysis and a coarse hand tremor.

CLINICAL WORKUP

Lumbar puncture can help aid in the diagnosis:

  • Anti-WNV antibodies can be detected.
AT WHAT POINT DO WE CONFIDENT IN MAKING THE DIAGNOSIS?

 

WHAT ELSE ARE WE WORRIED ABOUT?

 

HOW DO WE TREAT IT? 

 

HOW WELL DO THE PATIENTS DO?

 

WAS THERE A WAY TO PREVENT IT?

 

OTHER FACTS?

 

FURTHER READING

DynaMed

UpToDate

 

Page Updated: 08.10.2016