I330 



TYPHUS 



these observers contracted the disease, and Prowazek died. The 

 further investigations of Rocha-Lima have already been noted, and 

 it only remains to say that he found that lice kept at 23° C. did not 

 become infective, and the organism did not develop, but at 32° C. 

 the organism did develop, and the lice became infective. These 

 results are in direct contradiction, as regards temperature, to those 

 of NicoUe, Comte, and Conseil, of Ricketts and Wilder, and of 

 Anderson and Goldberger, and directly opposed to the distribution 

 of the disease. Da Rocha-Lima believes the virus is passed on to 

 a second generation of lice, of which larvae produced from eggs laid 

 by a louse six days after an infective feed are themselves infected. 

 The organism will develop in the human and not in the pig 

 louse. 



In 1917 Da Rocha-Lima pointed out that Ricketts and Wilder, 

 Gavino and Girard, and McCampbell, have found the parasite in 

 human blood; Von Prowazek in leucocytes; and himself in blood, 

 in smears, and in sections. 



Also in 1917 Otto and Dietrich obtained infections best by 

 allowing lice to feed on the fifth to seventh day of the illness, as 

 only 4-5 per cent, became infected on the twelfth day, and all are 

 negative after the fall of the temperature. They infected lice from 

 a patient sine exanthem, and they confirm Rickettsia. On the 

 other hand, Brumpt is of opinion that this organism in the louse has 

 nothing to do with typhus. Arkwright, Bacon, and Duncan's recent 

 observations are in favour of Rickettsia prowazeki playing an etio- 

 logical role. Futaki's Spirochceta exanthematotyphi, found in April, 

 1917, has been proved to have nothing to do with the disease. 



Serological Investigations. — In 1916 Nicolle and Blaizot prepared 

 an immune serum in horses and asses by the inoculation of emulsions 

 of spleen and suprarenal capsules of infected guinea-pigs, and tested 

 its curative power on non-immune guinea-pigs, in which it prevents 

 the disease if inoculated in the stage of incubation, and stops the 

 fever at the onset and during the first and second day, but later 

 its action is doubtful. They then tested it upon nineteen human 

 patients, when all cases treated in the early stage recovered quickly, 

 the temperature fell, the pulse and urine quickly improved, but the 

 nervous symptoms required repeated inoculation. It was used 

 in maximum doses of 10 c.c. per diem. In cases in which the 

 disease had been progressive for some time the serum acted slowly. 

 In 1918 Netley and Blaizot showed that the so-called Brill's disease 

 m Paris is typhus, and that guinea-pigs rendered immune to the 

 Parisian typhus are immune to the Tunisian strain. 



Prophylaxis. — Many observers (Maitland, Strong, Hunter, 

 Jackson, Castellani, etc.) have demonstrated in practice the vital 

 importance of louse destruction in the prophylaxis of the disease. 



Relapsing Fever. — ^Since 1739 it has been noticed that typhus 

 and relapsing fever go side by side in an epidemic. We now know 

 that the reason is because they are both spread by lice. 



Climatology. — ^Typhus is essentially a disease of temperate and 



