110 
PROPHYLAXIS OF MALARIA. 
blood examinations of the inhabitants should be indicated on the 
map, thus showing the relation of breeding places to such infections. 
The map should also show the ratio of infected individuals and 
mosquitoes and the most severely infected districts. The work of a 
few days in the examination of the blood of the inhabitants, the dis¬ 
section and examination of mosquitoes, and the location of breeding 
places of anophelines will result in a most valuable mass of data, 
enabling one to judge of the advisability of locating a post in the 
region investigated, and what methods would be best adapted to 
ridding the region of malarial infection. Such a malaria survey is 
just as important to the future health of the command as the ques¬ 
tion of an adequate and pure water supply. 
In posts that are known to be malarial the prophylactic methods 
adopted must vary with local conditions, and the best way to become 
acquainted with these conditions is to make a malaria survey, just 
as one would in deciding upon the location of a site for a permanent 
post. The post should be districted upon a map and a most careful 
search made for the breeding places of mosquitoes, while, coinci- 
dently, the species of mosquitoes present should be ascertained and 
the ratio of infected insects. An examination of the blood of at 
least 40 adults and children living in the immediate vicinity of the 
post should be made, as well as of the same number of soldiers in the 
post, in order to ascertain the presence of latent infection, and the 
records of the post should be consulted as to the prevalence of 
malaria during the past. As soon as this preliminary survey is 
completed one will have data upon which to work out the best 
method or methods of prophylaxis for the particular locality investi¬ 
gated. While in rare instances it will be found that mosquitoes 
can be exterminated and that this is the only prophylactic measure 
that need be adopted, in the vast majority of posts the malarial prob¬ 
lem is best attacked by using all the methods at our command. 
These consist in the abolition of the breeding places of mosquitoes 
and their destruction in the adult stage by trapping and catching 
by hand, the protection of the command from their bites by screen¬ 
ing and the use of nets, and the destruction of the plasmoclia by 
quinine. The latter method may be omitted, so far as the healthy 
population is concerned, provided malarial infection is not very 
intense and the other methods mentioned will control the situation, 
but in badly infected posts, where it is impossible to get rid of mos¬ 
quitoes, quinine prophylaxis should be adopted during the malarial 
season. 
Every elfort should be made to rid the post and the surrounding 
country for a distance of at least 2 miles of breeding places of 
anophelines. Very often the most that can be done is to reduce their 
number, owing to the immense cost of drainage and filling in, but as 
