CHAPTER II 



Some Necessary Steps in Any Attempt to Prove Insect Transmission or 



Causation of Disease ^ 



W. Dwight Pierce 



The study of the causation of disease is attracting far more attention 

 today than it ever has in the past, but it is to be regretted that there is 

 not a larger proportion of this effort being directed toward locating 

 the possible intermediate hosts and invertebrate carriers. 



Many excellent investigations have been carried out with all other 

 phases complete, but the question of invertebrate carriers is often left 

 in a very indeterminate stage. The majority of the investigations which 

 have been seriously undertaken to determine invertebrate carriers have 

 been conducted on other continents than ours. There is a great field for 

 investigation along these lines open to the investigators in America. In 

 order to stimulate such research, I have attempted in this paper to set 

 down some of the necessary steps for successful investigation. 



I. COOPERATION 



I consider essential to a thorough investigation of disease trans- 

 mission, the establishment of a perfect working agreement and hearty 

 cooperation between one or more physicians and diagnosticians, one or 

 more parasitologists, and one or more entomologists. It is not safe, 

 nor does the effort bring the proper amount of credence, when one man 

 attempts to do the whole work. Each phase of such an investigation 

 should be handled by an expert on that phase. The day of the solitary 

 investigator is past and we are now in an era of group-investigations 

 which carry with them weight and conviction. Of course certain pre- 

 liminary steps may easily be taken by any one member of a proposed 

 group or it may be possible that they may arrive at an advanced stage 

 by independent work, but the time will come in each investigation when 

 a cooperation of investigators will attain the most satisfactory results. 



^ This lecture was printed in Science, n. s., vol. 50, No. 1384, pp. 135-130, August 8, 

 1919. 



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