<prompt> Shortest incubation period -PertusisInfluenzaDiphtheriaMeasles  <response>: Ans. is b i.e., Influenza Respiratory tract infectionsDiseaseCausative organismIncubation periodSmall poxVariola virus7-14 daysChicken poxHuman alpha herpes virus314-16 daysMeasles RubeollaRNA paramyxovirus10-14 daysRubella German MeaslesRNA Togavirus14-21 daysMumpsRNA Myxovirus14-18 daysInfluenzaOrthomyxovirus18-72 hoursDiphtheriaCorynebacterium diphtheriae2-6 daysPertussis Whooping coughBordetella pertussis7-14 daysMeningococcal meningitisNeisseria meningitis3-4 daysSARSCorona virus3-5 daysTuberculosisMycobacterium tuberculosisWeeks-years 