ig6 



Arthropods as Hosts of Pathogenic Protozoa 



becomes primarily a problem in economic entomology, — ^it is a ques- 

 tion of insect control, in its broadest interpretation. 



The lines of defence and offence 



against the disease as outlined by 



Boyce (1909) are' 



1. Measures to avoid the reser- 

 voir (man) : 



Segregation. 

 Screening of patients. 



2 . Measures to avoid Anopheles : 

 Choice of suitable locality, 



when possible. 

 Screening of houses and 



porches. 

 Sleeping under mosquito nets. 



3. Measures to exterminate the 

 Anopheles : 



Use of natural enemies. 



Use of cuhcides, oiling ponds, 



etc. 

 Drainage and scavenging to 



destroy breeding places. 

 Enforcement of penalties for 



harboring larvse or keeping 



stagnant water. 

 Educational methods. 

 4. Systematic treatment with quinine to exterminate the parasites. 



Mosquitoes and Yellow Fever 



Yellow fever was until recently one of the most dreaded of epi- 

 demic diseases. It is an acute, specific and infectious disease, non- 

 contagious in character but occurring in epidemics, or endemics, 

 within a peculiarly limited geographical area. It is highly fatal, 

 but those who recover are generally immune from subsequent at- 

 tacks. 



It is generally regarded as an American disease, having been 

 found by Cortez, in Mexico, and being confined principally to the 

 American continents and islands. It also occurs in Africa and at- 

 tempts have been made to show that it was originally an African 

 disease but there is not sufficient evidence to establish this view. 



129. Larva of Anopheles. After Howard. 



