CHAPTER XIX 



SCARLET FEVER HYDROPHOBIA INFANTILE PARA- 

 LYSIS TYPHUS FEVER YELLOW FEVER - 

 DENGUE PHLEBOTOMUS FEVER VACCINIA AND 

 VARIOLA MALIGNANT DISEASE 



Scarlet Fever 



VARIOUS organisms have been described in scarlet fever 

 a bacillus by Eddington, a streptococcus by Frankel and 

 Freudenberg, protozoa by Mallory and others. The 

 disease may be milk-borne, and in the historic Hendon 

 outbreak a streptococcus was claimed by Klein to be 

 the specific infective agent, but the researches of Crookshank 

 and others seem to disprove this. 



In 1885 an epidemic of scarlet fever occurred in Mary- 

 lebone, and was traced to infection conveyed by milk 

 supplied from a farm at Hendon. The infection could 

 not be traced to any human source, and it was therefore 

 concluded that the cows themselves were affected with 

 scarlet fever, and infected the milk. A vesicular eruption 

 was found on the udders and teats of the cows, and this 

 was regarded as the local manifestation of bovine scar- 

 latina. From the vesicles and crusts Klein isolated a 

 streptococcus which, although closely resembling the 

 Streptococcus pyogenes (as then known), differed slightly 

 from it ; on inoculation into calves it produced death, 

 with lesions of the kidney resembling those of the human 

 disease. Klein also isolated the same streptococcus in 



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