196 
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): 
vSegregation. 
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 culirides, oiling ponds, 
etc. 
Drainage and scavenging to 
destroy breeding places. 
Enforcement of penalties for 
harboring larvae or keeping 
129. Larva of Anopheles. After Howard. Stagnant Water. 
Educational methods. 
4. Systematic treatment with quinine to exterminate theparasites. 
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. 
