CONTROL OF INFECTIOUS DISEASES 765 



the disease. Neither isolation nor quarantine can be justified if im- 

 posed on non-infectious immun.cs, or on non-immunes who have not 

 been exposed. 



RULES FOR RELEASE OF " CASES" FROM ISOLATION 



The case, whether isolated at a hospital, at home with a trained 

 nurse in attendance, or at home without a nurse, will be set free, and 

 may go to school, work, etc., only after full recovery as determined 

 by the M. O. H., and in addition as follows: 



In Smallpox, after all scales, plaques, crusts, etc., have disappeared, 

 as determined by the M. O. H. 



In Scarlet Fever, not less than six weeks from onset and then only 

 if temperature, nose, throat, ears, etc., have been normal for one week, 

 no discharge of any kind from any orifice exists, and all wounds, sores, 

 herpes, etc., are completely healed. 



In Measles proper, on the fourteenth day from onset, which will be 

 the tenth day from beginning of rash. 



In Diphtheria, after three consecutive negative cultures have been 

 obtained from both nose and throat. 



In Typhoid Fever, eight weeks after onset. 



In Chickenpox, after all crusts, scales, scabs, etc., have disappeared. 



In Whooping Cough, one week after last whoop, or six weeks from 

 first whoop, whichever comes first. 



In Mumps, three weeks from onset. 



In German Measles, one week from onset. 



PLACARDING OF HOUSE EXTERNAL 



If the case goes to a hospital, no placard is placed on the home from 

 which he came, notwithstanding that exposed non-immunes may be 

 quarantined there, unless the quarantine is not properly observed; 

 whereupon a placard may be used in any disease, or a special police- 

 man detailed to w r atch the house or both. 



If the case remains at home, where the family occupies a house, 

 both front and rear entrances are placarded in certain diseases (Small- 

 pox, Scarlet Fever, Measles, Diphtheria and the " Rarer Infectious 

 Diseases' 1 mentioned above, under the Provincial Law; in certain 

 others, typhoid fever, chickenpox, whooping cough, mumps, German 

 measles, placarding is optional and is enforced only if isolation or 



