129 



Steinhaus, E. A. 19*4-1 A study of "bacteria associated with 

 thirty species of insects. J. Bact. , k2, 757-790. 



Eberthella typhosa (Zopf ) Weldin 



Insects concerned: The house fly, Musca domestica ; the 

 blue-bottle fly, Chrysomyia megacephala ; the cockroach, 

 Periplaneta americana ; the mosquito, Aedes aegypti ; and 

 ants. 



A great deal has "been written concerning the trans- 

 mission of Eberthella typhosa by insects. The most often 

 incriminated insect is the common house fly, Musca domes - 

 tica . The typhoid "bacilli may contaminate the "body and 

 appendages of the fly or they may occur in the contents 

 of the intestinal tract or in the feces of the insect, 

 thereby contaminating food and drink. 



One of the earliest definite reports incriminating the 

 house fly in this regard was made by the Army Commission 

 appointed to investigate the cause of epidemics of enteric 

 fever in the Army camps of the Southern United States dur- 

 ing the Spanish -American War. This commission attributed 

 about 15 per cent of the cases of typhoid fever to trans- 

 mission by flies. Hamilton (1903) isolated typhoid bacilli 

 from flies caught in houses in which were patients ill with 

 typhoid fever. Ficker (I903) allowed flies to feed on 

 pure cultures of Eberthella typhosa and was able to culture 

 the bacilli from crushed flies 5 to 23 days afterwards. 

 Faichnie (1909a, 1909b) concluded from his experiments 

 that typhoid bacilli are not as readily transmitted via 

 the legs of flies as by the excrement of flies. These 

 examples represent the earlier work which incriminated the 

 fly as a carrier of Eberthella typhosa . (See also Howard, 

 1911; and Graham-Smith, 1913)* Since these investigations, 

 the evidence that flies, particularly Musca domestica , may 

 transmit the typhoid bacillus has been fairly well com- 

 pleted. 



Experimentally, Chow (19^0) found Eberthella typhosa 

 as well as Shigella dysenteriae to survive for 5 or 6 

 days in or outside the body of Chrysomyia megacephala . 

 However, he did not find E. typhosa associated with flies 

 of this species which he caught in Peiping. 



Morischila and Tsuchimochi (Riley and Johannsen, 1932) 

 found that E. typhosa passed through the cockroach intes- 

 tine apparently unharmed. In 1922 Macfie (Riley and 

 Johannsen, 1932) got negative results. 



Darling (Wheeler, 191*0 performed a series of experi- 

 ments to determine whether ants carry E. typhosa on the 



