886 PATHOGENIC MICROORGANISMS 



onset is initiated by chills and fever, intestinal disturbances, head- 

 ache, muscular pains, hyperemia of the conjunctivas and al- 

 buminuria. In this stage death is rare, and during this time the 

 spirocha3tes are freely circulating in the blood. Blood injected 

 during this period into guinea-pigs produces a typical reaction. 

 The infectivity of the blood decreases from this time on, according 

 to Inada. From the seventh to the thirteenth day of the icteric 

 period, which, according to Inada, covers a little less than a week. 

 The symptoms decrease, the jaundice and hemorrhages into the 

 skin appear, together with great weakness, nervous and cardiac 

 symptoms. The two stages shade into each other and the second 

 period is the one during which death is most common. In cases 

 dead at this time the spirochaetes have disappeared from the blood, 

 and antibodies can be shown by the Pfeiffer test. During the second 

 stage, the spirochaetes are present in the urine and can be found 

 by the dark field. Inada showed them in 17.4 per cent of his cases 

 on the tenth day, with a gradually growing percentage up to 52.2 

 per cent. As antibodies develop the spirochaetes disappear from 

 the blood and from the liver. 



On the thirteenth and fourteenth day begins the convalescent 

 stage. The jaundice becomes less and anemia and emaciation 

 appear. Antibodies reach their highest point in the blood, the 

 spirochaetes completely disappear from the blood, and become more 

 abundant in the urine. Inada states that the only organ in which 

 the spirochaetes can be found at this time are the kidneys. By 

 the nineteenth and twentieth day, practically all cases show the 

 organisms in the urine. 



The incubation period of the disease is five to seven days. 



Etiology of Weil's Disease. A great many different microorgan- 

 isms have been described in the course of time as the cause of 

 Weil's disease. The question was definitely settled in 1916 by Inada, 

 Yutaka, Hoki, Kaneko and Ito 25 who described the Spirochoeta Ictero- 

 Haemorrhagiae. They found the organisms in the blood, liver, adrenal 

 glands and kidneys and transmitted it by intraperitoneal injection 

 into guinea-pigs. They also succeeded in cultivating the organisms 

 by the Noguchi method. There can be no question whatever at 

 the present time concerning the etiologieal importance of this or- 

 ganism in Weil's disease. Tnadn ;md his en-workers inoculated 



K Inada, and coworkers, Jour. Exper. Med., 23, 1916, 377. 



