ABSTRACT
This chapter sketches the work of Americans in controlling certain diseases of tropical and sub-tropical climates. Texas Fever in cattle, and Hookworm disease and Yellow Fever, the two last named being human diseases which in past experience have destroyed more health in some parts of America than any other single disease, except Malaria and Tuberculosis. Theobald Smith's, American biological investigator, earlier work on the micro-organism of Texas fever was published. He demonstrated the method of transmission, and showed that the protozoal parasite of the disease passed from the tick to its offspring through the ova. They proved that Texas fever was in fact conveyed by ticks. In 1899, Henry R. Carter, of the American Public Health Service, made careful field observations proving that a mosquito which has bitten a yellow fever patient cannot by biting another human being infect him until some two to three weeks have passed.
