376 SPECIFIC MICRO-ORGANISMS 



blood (black vomit). It is frequently fatal. Permanent im- 

 munity follows recovery. Reed, Carroll, Lazear and Agramonte/ 

 in 1 90 1, showed that the virus is present in the blood at least 

 during the first two or three days of the attack, that it will pass 

 through a porcelain (Chamberland B) filter and that it is naturally 

 transmitted from man to man by the mosquito Aedes {Stegomyia) 

 calopus, which becomes capable of inoculating the disease about 

 twelve days after sucking blood which contains the virus. The 

 mosquito probably remains infective as long as it fives and maybe 

 regarded as an essential agent in the spread of yellow fever. Pro- 

 phylactic measures based upon this deduction have been remarkably 

 successful in the suppression of the disease. 



The newer work of Noguchi suggests that there may be verte- 

 brate animals which serve as reservoirs of the yellow fever virus 

 in the tropics. 



iSpirochaeta (Leptospira) Hebdomadalis.- — Ido, Ito and Wani^ 

 have found this organism, which resembles Spirochata ictero- 

 hcemorrhagicR in form and motion, in blood of patients suffering 

 from the Japanese seven-day fever, Nanukayami. It has been 

 successfully inoculated into young guinea-pigs. 



Spirochseta Gallica.- — Couvy and Dujarric de la Riviere' have 

 found a small spirochete in the blood in trench fever and have 

 suggested the name Spirochceta gallica for it. They also found the 

 spirochete in the liver and kidneys of guinea-pigs inoculated with 

 the human blood. Their results suggest the probable causal 

 relationship ^ of this organism to trench fever, but critical confirma- 

 tion has not yet appeared. 



Trench fever [Febris quintana (Wolhynica)] was probably 

 the most important epidemic disease of the world war up to 1918. 

 MacNee in 19 15 proved that it was transmissible by blood in- 



1 The publications of Reed, Carroll and their associates have been issued as a 

 volume entitled Yellow Fever, U. S. Senate Document No. 822, 6ist Congress 

 3rd Session, 191 1. 



2 Ido, Ito and Wani: Journ. Exp. Med., 1919, 29, p. 199. 

 ' Comptes rendus See. Biol., 1918, 81, p. 22. 



