incubation period 7-14 days
abrupt onset of high fevers often over 40degC lasting up to 2 weeks
severe headache and fatigue with photophobia
chills, myalgias
nausea, vomiting, cough may occur
4-6 days after onset of fever - rash starting on trunk spreading to the limbs but usually sparing the face, palms, and soles
severe cases may develop confusion and hypotension and may progress to renal failure, encephalitis, myocarditis, pneumonia, vascular collapse, gangrene and death