The minimum periods of isolation in various diseases shall be as follows: Scarlet fever, until 14 days from onset of the disease; diphtheria, until two negative nose and throat cultures taken not less than 24 hours apart are obtained; acute poliomyelitis, until 14 days from onset of the disease; epidemic meningitis, until seven days from onset of the disease, if the patient is free of acute symptoms; smallpox, until all primary crusts have been shed; measles and German measles, until seven days from onset of the rash; chickenpox, until seven days from onset of the disease, or until all primary crusts have disappeared; whooping cough, until four weeks from onset of catarrhal symptoms, or three weeks from onset of paroxysmal cough; mumps, until the swelling has disappeared; typhoid fever, until 10 days after temperature reaches and remains normal, and thereafter until two stools, taken not less than 48 hours apart, are negative for bacillus typhosus; all other diseases mentioned in Section 19-61, until, in the opinion of the director of public health, the patient can no longer transmit the infection. (Ord. Nos. 4404; 5514; 5869)