106 DDT — Killer of Killers 



areas in 1944, became contaminated with the virus, as was 

 revealed when the food was fed to chimpanzees. These ani- 

 mals, although they did not show any evidence of paralytic 

 poliomyelitis, showed virus in their stools for the next few 

 months, and this virus when passed on to monkeys caused 

 typical poliomyelitis lesions. 



Do flies play the same part in the transmission of polio 

 that mosquitoes do in malaria and yellow fever? We don't 

 know. But let's kill the flies and see what happens to the 

 spread of polio. 



The summer of 1945 was a good time to try out this 

 idea, for Rockford, Illinois was stricken with a severe polio 

 epidemic, and the effectiveness of DDT had been well estab- 

 lished. Within a few weeks, 17 people had died from polio 

 in Rockford, and many times that number were ill. Get 

 out the DDT! And that is what Dr. John R. Paul of Yale 

 University and the scientific expedition that he headed did. 

 The town of Rockford was sprayed, and sprayed thoroughly, 

 and many flies paid the penalty for their possible association 

 with polio. The polio epidemic gradually subsided, but 

 whether the DDT campaign contributed to the decline is not 

 known. It takes more than one experiment to gi\Q conclu- 

 sive results. 



Some day we may know the role of the fly in the spread 

 of polio, and if we find out that he is a killer as well as a 

 nuisance, we can be sure that an aroused populace will fill 

 its spray guns with DDT and wage relentless warfare against 

 this flying carrier of filth. 



The Fly and the Horse 



Have you ever stopped to consider the relationship be- 



