THE UNITED STATES Notable Advances.—The rapid growth of America was asso ciated with primitive sanitary conditions, so that epidemics of typhoid fever, cholera, yellow fever, typhus fever and other pre ventable plagues marred the development of the country. In many instances the water supplies were contaminated and sewage and wastes were disposed of by ready methods that were unsanitary and unsatisfactory. The reforms along these lines in recent years have worked hygienic marvels.
In 1893 Theobald Smith demonstrated that Texas fever of cat tle was transmitted by the bite of an infected tick, thus proving for the first time the great principle of insect-borne transmission of infection. Shortly afterwards the mosquito was shown to be the factor in the spread of malaria and then of yellow fever. Fol lowing this, other insects were found to be responsible for a long and growing list of infections. In 190o Carter discovered the ex trinsic period of incubation of yellow fever. In 1882 Carlos Fin lay of Cuba implicated the responsible mosquito, but it remained for the United States Army Medical Commission, consisting of Reed, Carroll, Lazear and Agramonte, to prove the fact by a con vincing demonstration in 1900. This discovery was soon put to practical use by White in New Orleans during 19o5 when, for the first time, an epidemic of yellow fever was stamped out before the advent of frost. The work of Gorgas which made the building of the Panama Canal possible was a dramatic demonstration in preventive medicine.
The cause and modes of spread of tularaemia, another insect borne disease, primarily of rabbits and secondarily of man, were discovered by McCoy and Francis, scientists of the Hygienic Laboratory of the U.S. Public Health Service. Ricketts lost' his life from typhus fever in Mexico City while unravelling the mys teries of that disease, and McClintock was a martyr to Rocky Mountain spotted fever while studying that tick-borne infection which has been revealed by American investigators. A triumph was achieved by the Dicks of Chicago who demonstrated the cause of scarlet fever and developed an antitoxic serum for its cure, a toxin for its prevention and a skin test (the Dick test) by which it is possible to determine who are susceptible and who im mune. Stiles pointed out the importance of hookworm disease and discovered an American species of this parasite. Trudeau founded at Saranac Lake, New York, the sanitorium for tubercu losis which now bears his name; Theobald Smith discovered the bovine tubercle bacillus; and Noguchi's brilliant achievements have placed some obscure problems on a secure scientific basis. In the field of nutrition, Atwater and Benedict, Osborne and Mendel, and Lusk and McCollum have enriched the important subject of dietetics, which is one of the most fundamental factors in health. Among other outstanding contributions should be mentioned the work of Goldberger on pellagra and Strong on trench fever. Oliver Wendell Holmes, as early as 1843, pointed
out the contagiousness of puerperal fever. The blessings of anaesthesia (q.v.) were among America's first contributions to preventive medicine.
The United States was early in the field to develop special schools for public health education. A School of Public Health was established by Harvard University and The Massachusetts Institute of Technology in Boston in 1913 (Rosenau, Sedgwick and Whipple). Other universities have participated in this move ment, especially the University of Pennsylvania (Abbott), Johns Hopkins University (Welch) and the University of Michigan (Vaughan). Names especially associated with public health ad ministration are Biggs, Chapin, Shattuck, Wiley and Wyman. .
Health administration in the United States is part of the police power of the several states. The Federal Government has no con stitutional power for local administration of health codes. It has, however, full powers with reference to maritime quarantine and interstate quarantine; it acts in emergencies and it promotes pub lic health through demonstrations, co-operation and investiga tion. Federal health activities are centred in the United States Public Health Service, which is a bureau of the Treasury Depart ment. Each state has a health organization, and all the large cities and some of the smaller ones also have well organized health services. The county district is the weakest link in the sanitary chain, but in 1925, 28o of the 2,85o rural counties of the United States had full-time health officers. Many other agencies are active in preventive medicine throughout the country—for ex ample, the International Health Board of the Rockefeller Foun dation; the Rockefeller Institute for Medical Research ; the McCormick Institute for Infectious Diseases ; the Society for the Study and Prevention of Tuberculosis; the National Health Council ; the Metropolitan Life Insurance Company, as well as universities, health centres, etc. (M. J. Ro.)