CHAPTER XXVII 



Diseases Transmitted by the Cockroach 

 W. Dwight Pierce 



As cockroaches are so often found in houses and especially apt to 

 frequent garbage and waste about a house, and frequent the food in the 

 kitchen and on the table, it can readily be seen how easily they might 

 transmit disease in case they are capable of carrying the organisms on 

 their body or of retaining them in their systems. The cockroach feeds 

 on filth of many kinds and goes straight from this filth to food. As it 

 feeds on the food it contaminates the same with its feces causing noxious 

 odors which often ruin the food. We owe to Cao, the Italian investigator, 

 our principal knowledge of the manner in which the cockroach can trans- 

 mit disease organisms. Cao worked with the bacteria which might be 

 found in food and in carcasses and he may be said to have covered the 

 greater part of the bacterial organisms which the cockroach is most 

 likely to be able to transmit. There can be no question of the desirability 

 of controlling roaches in houses, hotels, and eating places. The necessity 

 of this is the greatest in public eating houses where the roaches can feed 

 on sputum and debris left by customers or by employees. A filthy em- 

 plo^'ce and a cockroach-infested restaurant make a combination to be 

 feared. 



In the following pages will be found a summary of the records which 

 have been made of the role of cockroaches in the transmission of organisms, 

 especially disease organisms. 



PLANT ORGANISMS 



Thallopht/ta: Fungi: Coccaceae 



Micrococcus nigrofasciens Northrup, cause of an insect bacteriasis, 

 has been experimentally transmitted to Periplaneta americana by North- 

 rup. 



Sarcina alba Eisenberg has been isolated from the feces of Blatfa 

 orient alis by Cao in several series of experiments, but in no case was it 

 found to be pathogenic after passage through the cockroach, even when 

 fed in pure culture, or with other foods. In experiments with other 



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