YELLOW FEVER AND THE LEPTOSPIRA 883 



In regard to the question of the identity of the yellow fever 

 spirochaete with that of Weil's disease, Noguchi states that serolog- 

 ical differentiation could be made. Polyvalent immune sera, one 

 specific for icteroides and the other specific for icterohemorrhagice, 

 showed a high neutralizing power for cultures of the homologous 

 group. He found, however, that the action of the sera is not 

 absolutely specific, since the injection of a sufficient amount of 

 anti-icteroides serum prevents a fatal outcome in guinea-pigs in- 

 oculated with multiple doses of the other organism, and vice versa. 

 Other forms of serum reaction showed the same lack of absolute 

 specificity. 



Subsequently, Noguchi attempted to protect guinea-pigs against 

 multiple doses by injection of immune sera. He produced polyvalent 

 immune serum by inoculation of a horse, and found that such serum 

 could protect guinea-pigs when administered during the period of 

 incubation, and modified the course of the disease when used in 

 the early stages, but had no perceptible result in the later periods. 



Subsequent to the experiments of Noguchi recorded above, 

 Noguchi and Kligler 21 obtained results of similar experimental sig- 

 nificance in Yucatan. 



PREVENTION OF YELLOW FEVER 



Success in the prevention of yellow fever has been one of the 

 important factors in the development of South and Central Ameri- 

 can countries. The conversion of Rio de Janeiro into a healthy 

 port by Oswaldo Cruz, the cleaning up of New Orleans and the 

 work done by Gorgas in Panama indicate the splendid role which 

 an understanding of the relations of transmission in this disease 

 have played in the progress of civilization. Knowing what we do 

 about the Stegomyia and the part played by it in transmission, 

 preventive measures must depend primarily upon the suppression 

 of the mosquito and the isolation of cases from which mosquitoes 

 may acquire the infection. The disease is never, as far as we know, 

 conveyed by direct infection from man to man, or by soiled clothing, 

 etc., and in consequence there is no necessity for care in these 

 matters. The stegmoyia breeds particularly in rather pure water, 

 such as found in rain water cisterns, and fortunately does not, like 

 some other mosquitoes, breed in swamps, ponds and other natural 



NogucM and Kligler, Jour. Exper. Med., 32, 1920, 601. 



