HOUSEHOLD AND CAMP INSECTS II 



Disease and flies. The feeding habits of the fly admirably adapt 

 it to the spread of disease. It is well known that moist materials, 

 such as various foods or pathogenic^discharges from the human 

 system, are attractive to these insects, and there is abundant evi- 

 dence to show that they pass quickly from one to the other. The 

 fluids are sucked up into the crop and at times may be regurgitated. 

 The crop contents of a fly may literally swarm with disease germs, 

 especially in insanitary areas, and investigators have demonstrated 

 that certain disease germs may pass through the digestive tract of 

 the fly in a viable condition. This means that disgorged material 

 from the crop, the normal dejecta of the fly, and any particles from 

 the hairy legs or bodies may convey a serious, if not deadly, in- 

 fection. Flies are active agents in the dissemination of typhoid 

 fever and other diseases of the digestive tract, such as cholera and 

 summer diarrhoea of children, and carriers of the germs of tuber- 

 culosis, anthrax, plague, trachoma, septicemia, erysipelas and yaws. 

 There is also evidence to show that the house fly is a probable car- 

 rier of trypanosomyasis. 19 It is very probable that other infections 

 may be conveyed by this insect, and the obvious deduction is that 

 it is an extremely dangerous pest in all places where pathogenic 

 material may be exposed. 



The typhoid outbreak in army camps during the Spanish War 

 was due in very large measure to flies carrying disease from latrines 

 to mess tables. It is particularly dangerous under such conditions 

 to eat cold foods of any kind. This is exemplified by a typhoid out- 

 break occurring in the Minnesota iron range where there were 

 abundant opportunities for fly infection. The Finns and Swedes, 

 though far more cleanly in habits and environment than the 

 Austrians and Italians, were chief sufferers, due to the fact, it is 

 believed, that the former two lunched frequently during the day 

 upon cold food which was freely accessible to insects, while the 

 Italians and Austrians ate hot meals and used but little milk. 20 



The effect of adequate precautions is shown by the following: 

 Soldiers quartered on Brandywine creek, Pennsylvania, used as a 

 sink an abandoned, bottomless canal boat in the Delaware river, and 

 not a single case of intestinal disease occurred. 21 Futhermore, in- 

 fection with typhoid fever is much less frequent among messes 



10 Darling. Internat. Cong. Hyg. & Demog. Trans., xv, sect, v, 1913. 



20 Washburn. State Ent. Minn., I3th Rep't, p. 135-41. 1910. 



21 Skinner. New Orleans Med. & Surg. Jour., 61 1950-59. 1909. 



