THE RELATIONS OF BACTERIA TO DISEASE 53 



Contact infection is the chief source of danger in 

 those communicable diseases in which infectious 

 materials are discharged from the nose and throat, 

 such as tuberculosis, diphtheria, measles, pneumonia, 

 influenza, scarlet fever, whooping cough; and also 

 in those diseases in which the infectious materials 

 are discharged in the urine and feces, as in typhoid 

 fever, dysentery, and cholera. 



