242 BACTERIA, YEASTS, AND MOLDS 



the times when there is most chance of contagion, and 

 that all well persons should, so far as possible, be kept 

 away from the vicinity of these patients at the time of 

 coughing. If this is done and the sputum is cared for, 

 the chance of contagion is much reduced. 



The question often arises how long the isolation should 

 be continued. One must usually depend upon the physi- 

 cian or board of health for an answer to this question, 

 since the period of isolation varies with different diseases. 

 For scarlet fever it is about six weeks ; for whooping cough 

 it is certainly as long ; for diphtheria the time of necessary 

 isolation is very variable, and our health boards and physi- 

 cians have not yet determined how long an isolation is neces- 

 sary to prevent a convalescent patient from transmitting 

 the disease to other children. Upon this matter nothing 

 positive can be said at the present time. In general, the 

 period of isolation must be determined for each disease 

 by the advice of physician or board of health. 



Excreta. In the case of diseases located in the alimen- 

 tary canal, and distributed by excreta, isolation of the 

 patient is not so necessary, but everything that comes in 

 contact with the discharges from the alimentary canal 

 should be carefully guarded. This will include not only 

 the discharges from the intestine but also those from 

 the mouth. All possible precautions should be taken to 

 prevent any such material from being distributed through 

 the household. Such diseases can very easily be confined 

 to the patient and the sick room if care be taken with 

 the excreta, if all soiled materials coming in contact with 

 the patient be properly treated, and all eating utensils 

 thoroughly disinfected. 



