Brill Zinsser disease is caused by

DiseaseEtiologyDescriptionGroup Affected/Epidemiologic FactorsClinical SyndromeEpidemic typhusRickettsia prowazekiiMaculopapular eruption appearing inaxillae, spreading to trunk and later toextremities; usually spares face, palms, soles;evolves from blanchable macules to confluent eruption with petechiae; rash evanescentin recrudescent typhus (Brill-Zinsserdisease)Exposure to body lice;occurrence of recrudescenttyphus as relapseafter 30-50 yearsHeadache, myalgias;moality rates 10-40% ifuntreated; milder clinicalpresentation in recrudescentformRef: Harrison; 19th edition; Page no: 128