I230 



YELLOW FEVER 



towns during yellow-fever epidemics, though rare in preceding 

 years. With regard to bilious remittent fever, a good account 

 of this disease was given in 1842 by Burton in the first volume of the 

 British Medical Journal (then called the Provincial Medical Jour- 

 nal). In 1848 Nott, of Mobile, accused some insect or mosquito 

 of being the possible carrier of yellow fever. In 1876 Dowell, 

 of Galveston, showed that mosquitoes and yellow fever obeyed 

 the same natural laws, and in 1878 it was demonstrated in Mobile 

 that quarantine of the patients, together with sulphur fumigation, 

 could control the epidemic. But it was not till 1881 that Charles 

 Finlay, of Havana, directly attributed the spread of the disease to 

 the mosquito. In 1882 Gererd, having caused a mosquito to 

 suck the blood of a patient on the fourth day of the fever, then 

 allowed it at once to bite his hand, with the result that he developed 

 in due course a mild attack of yellow fever. The credit of having 

 supported the mosquito theory for many years in numerous publica- 

 tions belongs to Finlay. 



In 1883 Freire, of Rio de Janeiro, thought that he had discovered 

 the cause of the disease in the shape of a micrococcus, and later 

 C. Valle, C. Finlay, and Gibier each described specific bacteria. 

 Sternberg studied the disease for years, but could find no definite 

 bacterial or other cause. He, however, in a certain number of 

 cases, came across a bacillus, which he called ' X. ' In 1897 Sanarelli 

 announced that he had found a bacterium {Bacillus icteroides) 

 which he believed to be the cause of the disease, and, further, he 

 prepared a serum for its treatment. Sanarelli 's findings were at 

 first confirmed by a large number of observers. 



In 1900 Reed and Carroll announced that Bacillus X belonged to 

 the colon group of bacteria, a.ndB. icteroides to the hog-cholera group, 

 and was probably identical withB. cholerce suis. In our experience 

 B. icteroides is not identical with B. cholerca suis, but is a distinct 

 species, although it plays no part in the aetiology of the malady, 

 and is merely the cause of a secondary infection. In the same 

 year Reed, Carroll, Agramonte, and Lazear proved that the disease 

 could be produced by the subcutaneous injection of infected blood 

 into a non-immune person; that the disease was not contagious, 

 and was only spread by the bites of Stegomyia calopus. The agency 

 of the mosquito was speedily confirmed by Guiteras, Ribas and Lutz, 

 Marchoux, Salimbeni and Simond, Parker, Beyer and Pothier, and 

 later by Rosenau, Parker, Francis and Beyer. 



In 1903 Parker, Beyer, and Pothier concluded that the setiological cause 

 was Myxococcidium stegomyicB, found in infected mosquitoes, which they 

 believed to be an animal parasite closely resembling a Coccidium. Carroll, 

 however, refuted this, as did Marchoux, Salimbeni, and Simond, and finally 

 Rosenau, Parker, Francis, and Beyer clearly proved that M. stegomyi<8 was 

 a yeast normally found in mosquitoes. 



In 1905 Rosenau, Francis and Beyer showed that the disease 

 could be communicated by the inoculation of infected blood filtered 

 through the closest-grained Pasteur-Chamberland B filter which 



