<prompt> All are viral causes of PUO except:EBVCMVHIVLeptospirosis  <response>: Ans: d Leptospirosis Ref: Harrison, 16 ed, p. 116, 17th ed, p. 132A quite straight forward question. The answer is leptospirosis because it is not a viral cause of PUOPUO: Pyrexia of unknown originDefinition:Temperature 38.3IC on several occasionsOrA duration of fever of 3 weeksOrFailure to reach a diagnosis despite I week of inpatient investigationClassic PUOFever with 3 outpatient visitsOr3 days in the hospital without elucidation of a causeOr1 week of intelligent and invasive work upNosocomial PUOA temperature of more than or equal to 38.3degC develops on several occasions in a hospitalized patient who is receiving acute care and in whom infection was not manifest or incubating on admission.Neutropenic PUOTemperature more than or equal to 38.3degC on several occasions in a patient whose neutrophil count is 500ml or is expected to fall to that level in 1 or 2 days.HIV associated PUOTemperature more than or equal to 38.3ftC on several occasions over a period of 4 weeks for outpatients or 3 days for hospitalized patients with HIV infection. 