This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
[{'content': 'Organism that does NOT need vector for transmission: \nSelect and explain. \nA. Rickettsia prowazekii, B. Rickettsia rickettsii, C. Coxiella burnetii, D. Borrelia recurrentis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Coxiella burnetii causes Q fever. Q fever transmission differs from other rickettsial infection in that there is no ahropod involved in its transmission to man. Transmission results from inhalation, ingestion, abrasion or directly in conjunctiva. Ref: Park 21st edition, page 276.', 'role': 'assistant'}]