Incubation period: 2-15 days
A mild form of disease, a flu-like illness, "West Nile Fever", develops in approximately 20% of infected individuals.
Classic presentation:
- Anorexia
- Vomiting
- Abdominal pain
- Diarrhea
- fever
- Headache
- conjunctivitis
- Eye pain
- Pharyngitis
- facial congestion
- diffuse lymphadenopathy
- rash
Possible Complications:
- Dehydration
- Arrythmias
- Limb weakness
- Respiratory failure
A more severe form of West Nile virus, neuroinvasive disease, is evident in less than 1% of infected persons, particularly males, elderly, alcoholic, diabetic, immunosuppressed, and hypertensive.
The rash seen in 20% to 60% patients with West Nile virus represents either viremia or host's immune response. Rash is more common in young individuals, women and West Nile fever, and starts in the 3rd day(range 3-12) of illness as small macules, papaules, maculopapules, and vesicles located on the trunk. Lesions spread to the proximal extremities, last for 7-14 days, and resolve without scarring or desquamation. The rash is roseola-like, morbilliform. The rash may be associated with pruritus, hyperesthesia.
Unlike dengue virus rash, West Nile rash is ill defined and spares mucous membrane and the face, palm, and soles.
West Nile virus has become the most common cause of encephalitis.
Treatment is still experimental.
