disease has location respiratory system disorder infectious disease respiratory tract infectious disorder Invasion of the host RESPIRATORY SYSTEM by microorganisms, usually leading to pathological processes or diseases. infections, upper respiratory SCTID:275498002 respiratory infections MESH:D012141 upper respiratory tract infections upper respiratory infections infections, respiratory tract infections, respiratory infections, upper respiratory tract infection, respiratory tract ICD9:519.8 respiratory tract infection MONDO:0024355 respiratory infection, upper respiratory tract