TYPHOID FEVER 135 



almost wherever they happen to be" (Howard, 191 1, p. 141). 

 Newstead (1507, p. 16) in his Liverpool report writes to the same 

 effect. "In the course of my investigations, more especially on 

 hot days, numbers of flies were seen hovering over or feeding on 

 ' human dejecta.' The freces were generally those of children, 

 and were lying, as a rule, a few feet from the doorways, in the 

 courts or in passages behind the houses. In one instance no 

 less than five patches of human excreta were lying in one court, 

 and all of them were attended by house-flies." It is not im- 

 probable that a small proportion of these dejecta are deposited 

 by ' typhoid carriers.' Moreover the possibility of fly infection 

 has received little attention hitherto, even in those towns in which 

 suitable conditions occur. 



In certain cities data have been obtained which are sufficient 

 to afford information as to the general time relationship between 

 fly prevalence and the incidence of typhoid fever. Niven (1910) 

 has carried out investigations of this nature since 1904 in Man- 

 chester, Rosenau, Lunsden, Kartle and Howard made similar 

 investigations in Washington in 1909 and Hamer (1909) in 

 London. As a whole these observations seem to indicate that 

 there is little relationship in these cities between the prevalence 

 of flies and the incidence of typhoid fever. It must be re- 

 membered, however, in considering this question, that in large 

 cities many factors are in operation and that it is not impossible 

 as Niven believes that increased fly prevalence determines the 

 increased incidence of typhoid fever in London and Manchester 

 at the end of summer. 



More detailed observations were made in Washington by 

 Lennoden and Anderson (191 1), who found that the incidence of 

 typhoid fever upon the population using privies or yard closets 

 was greatest during the fly season. 



Howard (191 1, p. 148) quotes the opinions of several observers 

 living in rural districts in the United States, who believe that 

 flies are chiefly responsible for the spread of the disease in 

 country places. Reliable information on this subject is still 

 lackinsr. 



