Epidemic Typhus, also known as Epidemic Louse-borne Typhus, is caused by Rickettsia prowazekii bacteria transmitted through the bite of infected lice. A person becomes ill when contaminated lice are rubbed or crushed into the bite wound.
The infection occurs in mountainous regions of North America, South America, central and eastern Africa, and Asia. Humanitarian workers, missionaries, and military personnel working in crowded areas under poor hygienic conditions are at greater risk. Epidemic Typhus is often present among people living in overcrowded conditions with poor sanitation and outbreaks typically occur during the colder months of the year.
Usually symptoms appear 6 to 14 days after the bite. Malaise or general weakness occurs 1 to 3 days before the onset of sudden high fever, headache, chills, cough, muscle pain, sensitivity to light, and lack of energy. This is accompanied by a rash that appears on the trunk and limbs, but not the face, palms of the hands, or soles of the feet. Other symptoms may include nausea, diarrhea, and constipation. If untreated, the infection can lead to gangrene and necrosis (death of body tissue). Brill-Zinsser disease occurs when there is a relapse of Epidemic Typhus as Rickettsia prowazekii bacteria can remain latent for months or years after the original infection. Treatment includes antibiotics and supportive care of symptoms.
Freedom from louse infestation is the most effective protection against typhus.
There is no preventive medication or a commercially available vaccine against Epidemic Typhus.
Rickettsia prowazekii bacteria images, life cycle, and distribution maps:
Information last updated: January 2020