Abstract: The present invention provides a method of distinguishing a respiratory pathogen causing acute respiratory infection, wherein a pathogen to be distinguished is a pathogen colonizing the respiratory tract, the method comprising: a) measuring a gene copy number derived from a subject's cells, in DNA prepared from a sample containing the respiratory secretions of the subject; b) measuring a pathogen-derived gene copy number in the DNA; c) calculating the relative number of the pathogen-derived gene copy number to the gene copy number derived from the subject's cells; and d) distinguishing whether or not the pathogen is the respiratory pathogen, based on a distinguishment reference value and the relative number.

Abstract: Disclosed is a method of distinguishing an inflammatory pathogen causing acute respiratory infection wherein the pathogen to be distinguished is a pathogen residing in the respiratory tract, which comprises: (a) a step for counting gene copies originating in subject cells in DNA prepared from a specimen containing secretion from the respiratory tract of the subject; (b) a step for counting the gene copies originating in the pathogen in the DNA; (c) a step for calculating the relative value of count of the gene copies originating in the pathogen to the count of the gene copies originating in the subject cells; and (d) a step for distinguishing whether the pathogen is an inflammatory pathogen causing the disease or not based on the distinguishing standard and the relative value.