TY - CHAP M1 - Book, Section TI - RICKETTSIAL DISEASES A1 - Walker, David H. A1 - Dumler, J. Stephen A1 - Marrie, Thomas A2 - Kasper, Dennis L. A2 - Fauci, Anthony S. PY - 2017 T2 - Harrison's Infectious Diseases, 3e AB - The rickettsiae are a heterogeneous group of small, obligately intracellular, gram-negative coccobacilli and short bacilli, most of which are transmitted by a tick, mite, flea, or louse vector. Except in the case of louse-borne typhus, humans are incidental hosts. Among rickettsiae, Coxiella burnetii, Rickettsia prowazekii, and R. typhi have the well-documented ability to survive for an extended period outside the reservoir or vector and to be extremely infectious: inhalation of a single Coxiella microorganism can cause pneumonia. High-level infectivity and severe illness after inhalation make R. prowazekii, R. rickettsii, R. typhi, R. conorii, and C. burnetii bioterrorism threats. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/04/20 UR - accessbiomedicalscience.mhmedical.com/content.aspx?aid=1141410218 ER -