356 Co77Stant Care Is Needed for Health unit vi 



are trying to answer many puzzling this new science, as in all science, prog- 

 questions through experiments. They are ress is far more rapid when planning 

 beginning to arrive at answers by study- and research is centralized in properly 

 ing the spread of experimentally started equipped laboratories. It will be worth- 

 epidemics among mice and other ani- while for vou to summarize what you 

 mals raised in the laboratory. This kind have learned from the study of this prob- 

 of study promises to give results. But in lem by doing Exercise 10. 



Questions 



1. Why were epidemics more common and more severe formerly than 

 now? 



2. Which factors of the environment have long been known to increase 

 communicable diseases? What was needed before this connection 

 could be definitely estabhshed? What is meant by sanitation? Who is 

 responsible for proper sanitation in the Federal government? Who in 

 the local community? How does quarantine differ from isolation? 

 What two facts must be known about a germ before the spread of a 

 communicable disease can be stopped? 



3. Name three diseases that may be spread by a polluted water supply. 

 In what ways does a community protect itself against such disease? 

 Name two methods by which a community can obtain pure water. 



4. Give several reasons why milk may contain dangerous pathogenic 

 germs. Explain how milk is treated in pasteurization and what effect 

 this has on the germs it contains. 



5. What is a carrier? In which two ways may you become a carrier? 



6. By what four or five methods can a medical officer help to keep 

 germs from passing from a carrier (or diseased person) to a well 

 person? Discuss the danger of raw shellfish, uncovered food, flies, 

 meat which has not been inspected. 



7. How can the community protect itself against germs of respiratory 

 diseases? 



8. What is the carrier in these diseases: bubonic plague, typhus, yellow 

 fever, African sleeping sickness, malaria? To which group of animals 

 do all these carriers belong? Explain how bubonic plague is spread 

 and how we keep it from entering our country. 



9. Give facts and figures to show the importance of malaria. 



10. Explain how the cause of malaria was discovered by the combined 

 work of Laveran, Manson, and Ross. How was the connection be- 

 tween the malaria mosquito and the protozoan definitely established? 



11. What are the two hosts of the malaria protozoan? Describe its life 

 history in the human host and explain how it affects the host. 



12. Describe the protozoan's life history in the mosquito. 



13. What is the cause and what is the carrier of yellow fever? Describe 

 the experiments which proved this to be true. 



