THE PROPHYLAXIS OF MALARIA. 
INTRODUCTORY REMARKS. 
The discovery by Laveran of the parasites concerned in the etiology 
of the malarial fevers, and by Ross of the method of transmission of 
these parasites from man to man by the mosquito, has placed the 
prophylaxis of these infections upon a firm scientific basis; while the 
discovery of cinchona and its alkaloid, quinine, placed in our hands 
a true specific against the parasites. In many countries these dis¬ 
coveries have been taken advantage of in extensive campaigns against 
malaria, and such campaigns have been successful in proportion to 
the thoroughness with which measures based upon etiological facts 
have been applied in prophylaxis. 
In this bulletin, prepared at the request of the editorial board 
appointed by the Surgeon General of the Army, special stress will be 
laid upon those measures that are most applicable in the prophylaxis 
of malaria in the military service, including service in the field as 
well as in semipermanent camps and permanent posts. It is obvious 
that methods of prophylaxis that would he suitable in a permanent 
post might be impracticable upon the march, in bivouac, and in 
camps lasting only a day or two, so that it will be necessary to con¬ 
sider somewhat in extenso the prophylactic measures suitable under 
the special conditions brought about by military operations as well 
as those suited to preventing infection in permanent posts. 
At the present time our knowledge of the etiology of malarial in¬ 
fections is so extensive and accurate that no matter how badly a 
region may be infected or how difficult the local conditions may 
make the application of prophylactic measures some method may 
be adopted that will result in success. It is now proven beyond con- 
troversv that the malarial fevers are transmitted from man to man 
by mosquitoes belonging to the Anophelince; that these mosquitoes 
in order to become infective must have bitten an infected individual; 
that the malaria parasites undergo a definite cycle of development 
in both man and the mosquito, which, if interrupted at any stage, 
will result in the death of the parasites; and that these parasites, so 
far as we know, exist only in man and mosquitoes, so that it is 
unnecessary to consider other animal or insect hosts in the prophy¬ 
laxis of malaria. Therefore it follows that if it were possible to 
destroy all malaria-carrying mosquitoes or kill all the plasmodia 
in the blood of all infected individuals we would succeed in the 
9 
