Which of the following statement is TRUE about endemic typhus?

Endemic typhus: Caused by Rickettsia typhi (ubiquitous). Humans usually acquire the infection in an urban or suburban setting when bitten by an infected flea, which releases infected feces while sucking blood. Laboratory diagnosis of rickettsial diseases is based on serologic analysis rather than isolation of the organism. Although rickettsiae can be grown in cell culture or embryonated eggs, this is a hazardous procedure that is not available in the standard clinical laboratory. Clinical Findings: Gradual onset of malaise, cough, fever, and headache Maculopapular rash concentrated on trunk with rapid fading Severe disease with mental confusion and signs of hepatic, cardiac, renal, and pulmonary involvement may develop. Treatment: Antibiotic treatment is most effective with doxycycline, 100 mg twice daily orally Note: Rocky Mountain spotted fever is caused by Rickettsia rickettsii, and Q fever is caused by Coxiella burnetii. Ref: Levinson W. (2012). Chapter 26. Rickettsiae. In W. Levinson (Ed), Review of Medical Microbiology & Immunology, 12e.