CHAPTER LI 



MEASLES, SCARLET FEVER, TYPHUS FEVER, AND FOOT- 

 AND-MOUTH DISEASE 



MEASLES 



THE causative agent of measles is unknown to the present day, 

 and it would be a thankless task to review the literature of the many 

 attempts to isolate microorganisms from this disease, none of which 

 has resulted in throwing any light on the etiology. 



Attempts to produce the disease experimentally have frequently 

 been made, the earliest recorded being those of Home of Edinburgh, 

 published in 1759. 1 Home took blood from the arms of patients afflicted 

 with measles, and caught it upon cotton, and inoculated normal in- 

 dividuals by placing this blood-stained cotton on to wounds made in 

 tlie arm. Home claimed that in this way he produced measles of a 

 modified and milder type in fifteen individuals. Home's results, how- 

 ever, while at first accepted, were assailed by many writers and it is 

 by no means certain that the disease produced by him was really measles. 



A number of other observers after Home attempted experimental 

 inoculation of this disease, and positive results were reported by Stewart 

 of Rhode Island (1799), Speranza of Mantua (1822), Katowa of Hungary 

 (1842), and McGirr of Chicago (1850). 



The experiments of all these early writers, however, are unsatisfac- 

 tory, owing to the necessarily unreliable technique of their methods. 



In 1905, Hektoen 2 succeeded in experimentally producing the dis- 

 ease in two medical students by subcutaneous injection of blood taken 

 from measles patients at the height of the disease (fourth day). The 

 experiments were carefully carried out and the symptoms in the sub- 

 jects were unquestionable. They demonstrated beyond doubt that the 

 virus of the disease is present in the blood. Attempts at cultivation 

 carried out with the same blood were entirely negative. It was also 

 shown by Hektoen's experiments that the virus of measles may be kept 

 alive for at least twenty-four hours when mixed with ascitic broth. 



1 Home, " Medical Facts and Experiments," Edinburgh, 1759. 



2 Hektoen, Jour. Inf. Dis., ii, 1905. 



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