WNV Information for Clinicians


West Nile Fever

Most people who become infected with West Nile virus (WNV) develop no clinical illness or symptoms.  In previous outbreaks in the Northern Hemisphere, an estimated 80% of people who became infected with WNV never developed symptoms attributed to the infection. Of the approximately 20% of infected people who do develop symptoms, most develop what has been termed West Nile fever. The incubation period for WNV infection is thought to range from about 2-14 days, although longer incubation periods have been documented.

Clinical Features of West Nile Fever

  • Fever
  • Headache
  • Fatigue
  • Skin rash on the trunk of the body (occasionally)
  • Swollen lymph glands (occasionally)
  • Eye pain (occasionally)

Information provided by the CDC.  Additional information is available at:

    CDC - West Nile Virus: Clinical Description

The links below provide information for clinicians that may be useful in assessing patients that show symptoms of West Nile virus.   

     West Nile Virus Information and Guidance for Clinicians  

     West Nile Virus Case History Form

     Diagnostic Testing Guidelines for West Nile Virus

County of San Diego Physician Bulletin Archives:

For More Information On 
WNV Or Other Vectors Contact: 
(858) 694-2888  
SD Fight the Bite Homepage