<prompt> False statement for Pyrexia of unknown origin:Cause unknown despite more than 3 days of hospitalizationCause unknown even after 3 OPD visitsFever persisting after 1 month of regular treatmentUsually, fever more than 38.3 degree Celsius  <response>: Ans. C: Fever persisting after 1 month of regular treatment PUO was defined by Petersdorf and Beeson in 1961 as 1 temperatures of more than 38.3 degree C 101 degree F on several occasions; 2 a duration of fever of more than 3 weeks; 3 failure to reach a diagnosis despite 1 week of inpatient investigation The new definition is broader, stipulating 3 outpatient visits or 3 days on the hospital without elucidation of a cause or 1 week of intelligent and invasive ambulatory investigation 