Case Presentation:A 63 year old woman from Texas with no recent international travel presents to the ED with persistent fatigue which onset a month ago and is associated with anorexia and occasional fevers and chills. She has been to her family doctor who tested her for a number of viral illnesses and was told she had West Nile virus.
Clinical Question:
What other febrile illness could this be?
Answer:
This patient had dengue. Dengue is now endemic in the US, and locally-acquired cases have been reported in Florida, Texas and Hawaii. The fatigue and anorexia are typical and can last for weeks after other symptoms have resolved.
West Nile virus testing may be falsely positive when another flavivirus is present such dengue, yellow fever or Japanese encephalitis.
Bottom Line:
Other possible illnesses like dengue should be considered in patients who have tested positive for West Nile virus.
University of Maryland Section of Global Emergency Health
