Chapter IV. 
PROPHYLACTIC METHODS BASED UPON THE PROTECTION OF MAN 
FROM THE BITES OF MOSQUITOES. 
Where it is impossible to destroy all of the breeding places of 
mosquitoes or to kill the adult insects, the protection of man from 
the bites of these insects becomes a most important prophylactic 
measure. Especially has this been found true in the military service, 
where this method, together with quinine prophylaxis, often has to 
be depended upon entirely when troops are in the field in malarial 
localities, and even in semipermanent camps and permanent posts 
the protection of the troops from the bites of mosquitoes not infre¬ 
quently becomes of paramount importance owing to local conditions 
or for economical reasons. While, as has been stated, the abolition 
of the breeding places of mosquitoes is the ideal method of malaria 
prophylaxis either in military or civil communities and other meth¬ 
ods should never be substituted for this where it is possible to employ 
it, the fact remains that in most localities it is necessary to combine 
all of our methods of prophylaxis, and of them the protection of man 
from mosquito bites is one of the most valuable. 
This mechanical prophylaxis, as it is sometimes called, is secured 
by the proper screening of quarters and barracks, the use of mosquito 
nets for the beds and shelter tents, the wearing of head nets and 
gloves, and the use of various odorous substances which are smeared 
upon the skin for the purpose of preventing mosquitoes from biting. 
Screening .—The screening of barracks and quarters in posts in 
malarial regions is a most important and valuable prophylactic meas¬ 
ure and should never be neglected when the more permanent methods 
of drainage and filling in can not be employed or where their em¬ 
ployment only reduces the number of anophelines. While, in civil 
iife, the question of expense makes the employment of this method 
prohibitive in many localities, in the military service it should not 
enter into the question where posts are situated in regions where 
pernicious forms of malaria are prevalent, or where any form of 
malaria is prevalent to an extent that will seriously affect the 
efficiency of troops. 
The expense involved is admittedly great, in many instances, but 
if good screening material be obtained, the screens will, if properly 
cared for, last for years, and before they are worn out will have 
repaid many times the initial expense by the reduction in the amount 
of malaria among the troops and the consequent increase in efficiency. 
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