HIDEYO NOGUCHI 491 



material from six of twenty-seven cases of yellow fever studied, and the name Lepto- 

 spira icteroides was suggested for it. The writer was at that time unaware of Stim- 

 son's previous observation but was subsequently given an opportunity to study Stim- 

 son's original preparations in comparison with preparations of L. icteroides. Mor- 

 phologically, the organisms are exactly identical, and, in view of the fact that both 

 have been found in yellow fever, it seems reasonable to assume that they are one and 

 the same. Hence Stimson's interrogans takes precedence over the writer's icteroides 

 as the species name. 



L. interrogans was subsequently isolated from cases of yellow fever in Mexico, 

 Peru, and Brazil by various workers, by Kligler and the writer in Merida and Mor- 

 ropon in 1919 and 1920;' by Perez-Grovas- and Le Blanc, ^ independently, in Vera 

 Cruz in 1920 and 1921; by Godofredo Vianna and Biao-' in Palmeiras in 1923; and 

 more recently by Vianna and Vianna, Jr.,= in Bahia in 1926. The number of strains 

 isolated is comparatively small: six in Guayaquil, three in Mexico, four in Peru, and 

 four in Brazil. 



The morphological and cultural properties of the organism are similar to those 

 of other species of leptospiras except that the interrogans is in general smaller and finer 

 than the icterohaemorrhagiae, pyroxenes, or hebdomadis. As in the case of the other 

 varieties, the interrogans is seldom detected in the blood of patients, and is best dem- 

 onstrated by means of animal inoculations or cultivation. 



The cases from which the micro-organism was isolated were characterized bv 

 abrupt onset, chills, moderate or high fever, severe frontal headache, pains in the 

 back and legs, nausea, frequent vomiting, congested gums, puffed face, and general 

 malaise. In the later stages there were hemorrhages into various organs: the stomach, 

 giving rise to black or red vomit; the intestine, causing black or bloody stools; in the 

 bladder (hematuria), the subcutaneous tissues, and the lungs. Albuminuria was se- 

 vere in most cases, and complete anuria often occurred. 



In the experimental disease, the symptoms were similar: the onset acute, the tem- 

 perature rising abruptly after an incubation period of two to six days and continuing 

 for two to three days. General jaundice, albuminuria (sometimes anuria), and hem- 

 orrhages into the subcutaneous tissues, stomach, intestine, and lungs occurred soon 

 after the fall in temperature. The liver showed disseminated foci of necrosis, with ex- 

 tensive fatty degeneration, while the renal epithelia, especially of the convoluted 

 tubules, exhibited fatty as well as necrotic changes. Except for the lesser degree of in- 

 termediary-zone necrosis these changes are identical with those found in the human 

 tissues, as shown by W. H. Hoffmann's study'' of materials collected by Guiteras in 

 1 899-1 900, when the United States Army Yellow Fever Board under Reed was work- 

 ing in Havana, and by Gorgas and Guiteras. Cebus monkeys, inoculated with Bra- 



' Noguchi, H., and Kligler, I. J.: ibid., 32, 601-37; 33. 239-60. 1921. 



2 Perez-Grovas, P.: J.A.M.A., 76, 362. 1921. 



3Le Blanc, T. J.: /. Trop. Med., 28, 169. 1925. 



''Torres, O.: Scicncia med., 2, 219, 313. Bahia, 1924. 



5 Vianna, Jr., G., and Vianna, G.: Soc. med. e cinirg. June, 1926. 



^Hoffmann, W. H.: Seiichenbekdmpfung, 2, 279. 1925. 



