CHAPTER XXXVIII 



MICROBE OF THE WHOOPING COUGH 



THE sole cause of the whooping cough is a mi- 

 crobe, Fig. 73. Every new case comes from some 

 previous case. The disease is exceedingly conta- 

 gious and infectious. It may be taken by coming 

 in contact with one who has it; or, as the germ 

 floats in the air, the disease may be taken by 

 merely going into the presence of one who has it. 

 One scholar having the whooping cough in a school- 

 room, may give it to every other scholar in the 

 room. 



The primary cough may continue three weeks 

 before the whooping begins. During this time the 

 cough may be taken for a simple cold ; yet it is all 

 the while contagious and infectious. Hence the 

 danger of spreading the disease. After the whoop- 

 ing begins, the cough may continue six weeks 

 more, all the while infectious, nine weeks in all. 



The period of incubation is fourteen days; that 

 is, from the time of exposure to the time of be- 

 ginning to cough. 



In the United States about 10,000 die every year 

 with the whooping cough. This means 190,000 

 throughout the world. Nearly all these deaths oc- 

 cur among children under four years old; two 



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