A man presents with fever, chills 2 weeks after a louse bite. There was maculopapular rash on the trunk which spread peripherally. The cause of this infection can be:

Ans. is 'd' i.e., Epidemic typhusRef: Harrison, 19th/e, p. 1154; Ananthanarayan, 9th/e, p. 405)Louse borne diseases - Epidemic typhus, Brill Zinsser disease, Trench fever.Humans are the natural reservoir for R. prowazekii, which is prevalent worldwide and transmitted by body lice when louse feces are scratched or rubbed into bite or other wounds (or sometimes the mucous membranes of the eyes or mouth). Headache is generalized and intense. Small, pink macules, which appear on the 4th to 6th day, rapidly cover the body, usually in the axillae and on the upper trunk and not on the palms, soles and face. Later, the rash becomes dark and maculopapular.