epidemic typhus

Introduction

epidemic typhus is caused by Rickettsia prowazekii which is spread by the human body louse

rare in developed countries
most cases occur in areas with poor sanitation, crowding, war or natural disasters where body lice infestations are more common
outbreaks have been reported in parts of Africa, Central and South America, Eastern Europe, and Asia
cases have occurred in the United States, often linked to contact with flying squirrels

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