BACTERIA AND HEALTH 



387 



leave the host in special ways ; (2) that they are commonly 

 transferred to other hosts in special ways ; and (3) that they 

 then enter the bodies of the new hosts in special ways. 



TRANSMISSION OF COMMUNICABLE DISEASES 



Disease 



How Germs Come 



OUT 



Chicken pox . 

 Diphtheria . . 



German measles 

 Measles . . . 



Mouth and nose 



spray 

 Mouth and nose 



spray ; saliva 



Mouth and nose 



spray 

 Mouth and nose 



How Germs are 

 Carried 



Mumps 



Scarlet fever 



Septic sore throat 



Smallpox 



Tetanus (lockjaw) 

 Trachoma . . . 

 Tuberculosis . . 



Typhoid fever . . 



\\ hooping cough 



spray 

 Mouth and nose 

 spray ; saliva 



Mouth and nose 

 spray ; saliva 



Mouth and nose 

 spray ; saliva 



Mouth and nose 

 spray 



Contact 



Contact 



Mouth and nose 

 spray 



Mouth, excretions, 

 intestinal waste, 

 and occasionally 

 through skin 



Mouth and nose 

 spray 



Air 



Air, objects ex- 

 posed to spray 

 or saliva 



Air 



Air 



Air, objects ex- 

 posed to spray 

 or saliva 



Air, objects ex- 

 posed to spray 

 or saliva 



Air, objects ex- 

 posed to spray 

 or saliva 



Air 



Hands or objects 



Hands, towels, etc. 



Hands, objects, 

 etc. 



Hands, various ob- 

 jects, flies 



Air 



How Germs Enter 



Nose and mouth 

 Nose and mouth 



Nose and mouth 

 Nose and mouth 

 Nose and mouth 



Nose and mouth 



Nose and mouth 



Nose and mouth 



Breaks in skin 

 Contact with eyes 

 Nose and mouth, 



food 

 Food 



Nose and mouth 



429. Infection. The table above tells how the germs of 

 a number of common diseases are thrown off, how they are 

 carried about, and how they enter the bodies of the new hosts. 



