226 INFECTION AND IMMUNITY 



are not so apparent as in many other diseases. In- 

 deed some authors assert that the children of the rich 

 suffer even in greater proportion than those of the 

 poor. In the United States the mortality among the 

 coloured population is considerably less than among 

 the whites 12 deaths in 1000 from all causes among 

 whites and 2.6 per 1000 among coloured. More 

 deaths occur during the winter than during the sum- 

 mer months. This is no doubt partly due to the 

 unfavourable influence of exposure to cold in the 

 development of some of the most fatal complications 

 which are likely to occur during the progress of the 

 disease nephritis, pneumonia. 



For the prevention of scarlet fever we must de- 

 pend entirely upon isolation of the sick and the dis- 

 infection of all infectious material, inasmuch as no 

 method of protecting by inoculation is known, The 

 general directions given with reference to the disin- 

 fection of the sick-room and its contents on page 220 

 apply equally to scarlet fever. Special care must be 

 taken with reference to the sputa of the patient, 

 which should be disinfected by the same methods 

 recommended for tuberculosis (p. 171) and other 

 diseases in which the infectious agent is present in 

 secretions from the mucous membrane of some por- 

 tion of the respiratory tract. 



The advantages attending the removal of scarlet 



