The infectivity of a patient with diphtheria is ?

Ans. is 'd' i.e., For 15 days after infection o The period of infectivity may vary from 14 to 28 days from the onset of the disease, but carriers may remain infective for much longer period. o A case or carrier may be considered non-communicable when at least 2 cultures properly obtained from nose and throat, 24 hours apa, are negative for diphtheria bacilli.