356 



Microbes and You 



events required by some organisms which must pass through vari- 

 ous stages in a life cycle. 



As our knowledge about these diseases has increased, prophy- 

 lactic and therapeutic drugs have been developed. The use of 



Fig. 60. Typhus control by dusting Russian prisoners of war in 

 Germany with DDT. (Courtesy of the Armed Forces Institute of 

 Pathology, Washington 25, D.C. Negative #B-814-0.) 



vaccines in the prevention of typhus has produced extremely en- 

 couraging results, and when typhus vaccination is coupled with 

 direct attacks on the vectors of this disease through such measures 

 as treating individuals with DDT, Chloradane, or Lindane, typhus 

 can be controlled. 



