Which member of the order Rickettsiales is characteristically acquired by humans through inhalation of contaminated aerosols from livestock products such as placentas, and unlike other rickettsial diseases, typically presents with pneumonia and hepatitis WITHOUT a skin rash?

• A Rickettsia prowazekii
• B Orientia tsutsugamushi
• C Coxiella burnetii ✓
• D Rickettsia conorii

Explanation

Coxiella burnetii, the agent of Q fever, is transmitted by the airborne route from infected cattle, sheep and goats, especially birthing products, and causes an acute febrile illness with atypical pneumonia and granulomatous hepatitis. Rash and eschar are absent because Coxiella does not infect vascular endothelium, unlike Rickettsia and Orientia species which produce rash through endothelial infection and vasculitis.

Reference: Ananthanarayan and Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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