THE ADAPTABILITY OF CONTROL MEASURES TO 
THE MALARIA VECTORS OF THE CARIB¬ 
BEAN REGION 
By HENRY W. KUMM 
INTERNATIONAL HEALTH DIVISION, ROCKEFELLER FOUNDATION, BALTIMORE, MD. 
Mosquito control in the Caribbean region 
was initiated in the early years of this cen¬ 
tury by General Gorgas in Cuba and Pan¬ 
ama. At first, similar work in neighboring 
countries yielded disappointing results, so 
that for some time it was concluded that 
only localities having financial resources 
comparable to those of the Panama Canal 
region could hope for success. In this paper 
I will show that while adequate control of 
malaria has been maintained by the Health 
Department of the Canal Zone, other coun¬ 
tries and organizations in the Caribbean 
region are now making significant progress. 
At the present time there is no known 
means of eradicating malaria from large 
rural areas of the American tropics. It is 
possible, however, to control malaria in 
circumscribed zones which are of sufficient 
importance to justify the necessary ex¬ 
pense. 
Most authorities agree that at the present 
state of our knowledge permanent measures 
are the most economical. The use of oil or 
Paris green to destroy anopheline larvae 
is at best only temporary. These measures 
undoubtedly have their place and in certain 
circumstances are the only ones available, 
but whenever possible measures should be 
taken to “build out” malaria. Such a pro¬ 
gram has its admitted limitations, but it is 
better than nothing. 
At least 8 countries in the Caribbean 
region have malaria control programs and 
some of the larger commercial enterprises, 
such as the United Fruit Company and the 
Tropical Oil Company of Colombia, are 
obtaining highly significant results under 
their own control programs. In 1906 over 
80 per cent, and in 1938 only 1 per cent, of 
the employees of the Canal Zone contracted 
malaria. Yet in the last 24 years the mor¬ 
bidity rate for the Zone has never fallen 
below the 1 per cent which seems to be the 
irreducible minimum. 
The work of many investigators has 
shown that A. albimanus is the principal 
vector in 17 out of the 20 countries of the 
Caribbean region but much remains to be 
done before our knowledge will be com¬ 
plete. An accurate recognition of the prin¬ 
cipal malarial vectors in each country is 
important, because control measures di¬ 
rected • against one species may be useless 
against another. A. albimanus, for in¬ 
stance, breeds in ground pools in the sun, 
but A. darlingi prefers the shady margins 
of slowly running streams. In Cuba, breed¬ 
ing .of A. albimanus has been discouraged 
by the planting of shade trees, an excellent 
deterrent, but one that would not be effec¬ 
tive against A. darlingi. 
Dr. Gabaldon reports that in Venezuela 
A. albimanus is the principal vector, espe¬ 
cially along the sea coast and around Lake 
Valencia. However, he has initiated control 
measures against A. darlingi at three places, 
Cabudare, Acarigua and Maturin in the 
provinces of Lara, Portuguesa and Mona- 
gas. He feels that it is too early, as yet, to 
evaluate the effectiveness of these projects. 
In the island of Trinidad, de Verteuil and 
Spence (1937) attempted to control malaria 
transmitted by A. tarsimaculatus breeding 
in salt water. 
A malaria control program has been in 
operation in the Panama Canal Zone for 
the past 35 years and the number of em¬ 
ployees has at times exceeded 50,000. The 
malaria rates are given in Table I for per¬ 
sons living in the Panama Canal Zone and 
for the tropical employees of the United 
