2S NEW YORK STATK .MUSEUM 



c Typhoid fever .gradually clisai)pcare(l in the fall of 1898, with 

 the approach of cold wcatlicr, and the consequent disabling of 

 the fly. 



It is possible for the fly to carry the ty])hoid bacillus in two 

 ways. In the first place fecal matter containint^ the typhoid germ 

 may adhere to the fly and be mechanically trans])orted. In the 

 second place, it is possible that the typhoid l)aci]lus may be carried 

 ii' the digestive organs of the fly and may be deposited with its 

 excrement. 



Dr Alice Hamilton in 1903, studying the part played by the 

 house fly in a recent epidemic of typhoid fever in Chicago which 

 could not be explained wholly by the water supply nor on the 

 grounds of poverty or ignorance of the inhabitants, captured flies 

 in undrained privies, on the fences of yards, on the walls of two 

 houses and in the room of a typhoid patient and used them to 

 inoculate 18 tubes, from five of which the typhoid bacillus was 

 isolated. She further found that many discharges from typhoid 

 patients were left exposed in privies or yards, and concluded that 

 flies might be an important adjunct in the dissemination of this 

 infection. More recently, Dr Daniel D. Jackson investigating in 

 1907 the pollution of New York harbor, found that by far the 

 greater number of cases occurred within a few blocks of the water 

 front, the outbreak being most severe in the immediate vicinitv of 

 sewer outlets. He gives a series of charts showing an almost exact 

 coincidence between the abundance of house flies and the occur- 

 rence of typhoid fever, when the dates are set back two months to 

 correspond to the time at which the disease was contracted. Tlie 

 bacilli of typhoid fever were found by Fickcr in the dejecta of 

 house flies 23 days after feeding, while Hamer records the presence 

 of this bacillus in flies during a period of two weeks. Most sig- 

 nificant of all. it should be noted that competent physicians in 

 position to make extended observations upon this disease and the 

 methods by which it may become disseminated, are most strongly 

 ol the opinion that under certain conditions at least, the fly is a 

 most important factor. Epidemics spread by flies, according to 

 Dr \'eeder, tend to follow the directions of prevailing warm winds. 

 He considers flies the chief medium of conveyance in villages and 

 camps where shallow, open closets are used, thus affording the 

 insects free access to infected material, and where it is possible to 

 eliminate water and milk as the sources of infection. Drs Sedgwick 

 and Winslow, writing in 1903 state that " the three great means 



