Four per cent of the inhabitants of certain sections of the South have
malaria. This estimate, based on the reporting of 204,881 cases during
1914, has led the United States Public Health Service to give increased
attention to the malaria problem, according to the annual report of the
Surgeon General. Of 13,526 blood specimens examined by Government
officers during the year, 1,797 showed malarial infection. The infection
rate among white persons was above 8 per cent, and among colored persons
20 per cent. In two counties in the Yazoo Valley, forty out of every one
hundred inhabitants presented evidence of the disease.
Striking as the above figures are they are not more remarkable than
those relating to the reduction in the incidence of the disease
following surveys of the Public Health Service at thirty-four places in
nearly every State of the South. In some instances from an incidence of
fifteen per cent, in 1914, a reduction has been accomplished to less
than 4 or 5 per cent in 1915.
One of the important scientific discoveries made during the year was in
regard to the continuance of the disease from season to season. Over
2,000 Anopheline mosquitoes in malarious districts were dissected,
during the early spring months, without finding a single infected
insect, and not until May 15, 1915, was the first parasite in the body
of a mosquito discovered. The Public Health Service, therefore,
concludes that mosquitoes in the latitude of the southern states
ordinarily do not carry the infection through the winter. This discovery
indicates that protection from malaria may be secured by treating human
carriers with quinine previous to the middle of May, thus preventing any
infection from chronic sufferers reaching the mosquitoes and being
transmitted by them to other persons.
Although quinine remains the best means of treating malaria, and is also
of marked benefit in preventing infection, the eradication of the
disease as a whole rests upon the destruction of the breeding places of
Anopheline mosquitoes. The Public Health Service, therefore, is urging a
definite campaign of draining standing water, the filling of low places,
and the regrading and training of streams where malarial mosquitoes
breed. The oiling of breeding places, and the stocking of streams with
top-feeding minnows, are further recommended. The Service also gives
advice regarding screening, and other preventive measures as a part of
the educational campaigns conducted in sections of infected territory.
This study is typical of the scientific investigations which are being
carried out by the Public Health Service, all of which have a direct
bearing on eradicating the disease. The malaria work now includes the
collection of morbidity data, malaria surveys, demonstration work,
scientific field and laboratory studies, educational campaigns, and
special studies of impounded water and drainage projects.