Since a large proportion of disease is avoid able, all reasonable prevention methods should be developed to the utmost. The first measure for a people to adopt for self-protection is a quarantine against the importation of disease by immigration. Records of the incoming ves sel's health are examined at the quarantine station before the dock is reached, and inquiry is made concerning all cases of sickness or death on the voyage. Detention for a varying period may be ordered, all immigrants may be subjected to inspection and the boats may be fumigated. At the port of New York, for example, the stream of arriving immigrants is inspected for contagious eye diseases, hernia, and facial dermatoses ; mental defects are noted as observed, and these patients are separated for treatment or further individual examina tion or for return to the country from whence they came. In time of epidemics of cholera and yellow fever, for example, much disease is prevented by strict quarantine regulations. Sim ilar regulations have been enforced against people traveling from one State to another, or from urban to rural districts, as in 1916, during the epidemic of infantile poliomyelitis; and thereby the disease was confined to certain areas, and the number of possible contact cases was limited materially.
Constant preventive measures for the per manent population are taken by municipalities and States through various officials. Tenement house commissioners enforce ordinances re garding cubic feet of air space, the number of windows proportionate to the size of each mom, water supply, plumbing and sewerage, as well as the amount of ground to be left uncovered by the building erected thereon. Factories and workshops are supervised under mercantile inspection laws in order that air-space, ventila tion, water supply, plumbing, sewerage, light and fire protection may all be ample; State meat inspectors examine and approve or destroy car casses of animals slaughtered for food, tagging accepted portions.
State and local health boards cover a wide field of protection through their activities, with milk inspections including determination of specific gravity, butter fat, percentage and con tamination, as well as control of sanitary features of herding and stabling; licensing and inspection of midwives; suppression of nui sances, including the production of noxious fumes or smoke, as well as maintenance of fly breeding refuse, contamination of streams, etc.; abolishing of the common drinking cup and the common towel; prohibiting spitting in public places; requiring sanitary conditions in barber shops; more adequate control of tuberculosis; protection of public and private water supplies; control of communicable diseases, and promo tion of child hygiene.
Protection from and prevention of disease through control of communicable disorders are secured by thorough notification and very early report by physicians and other persons, and an immediate study of sources, in order to trace to the origin and eliminate the source in each instance, vaccinating and immunizing thor oughly and repeatedly, and establishing local headquarters where needed, furnishing diagnos tic service and also serums and vaccines.
Child hygiene, a measure of prime import ance, is promoted by conducting infant welfare campaigns, with traveling exhibits, lectures by members of the department staff, demonstra tions and talks by trained nurses, interviews with mothers' clubs and parent-teacher asso ciations and general public meetings. Infant welfare stations are established where mothers are instructed by station nurses and babies re ceive care. Child welfare exhibits are prepared for county fairs and similar gatherings, at which are distributed pamphlets containing in struction in disease, its cure and its avoidance. °Better baby° contests are inaugurated and motion picture films on child welfare are shown. Older sisters, on whose shoulders fall the care of the babies, are organized into °Little Mother Leagues," with pledge cards and certificates of membership, and information is communicated at these meetings.
In several cities prevention of disease among public school children is aided by daily inspec tion of all pupils by teachers, who set aside those apparently ill for skilled examination and disposal by the medical school inspectors. All eyes are closely scrutinized ; throats are inspected for adenoids and enlarged faucial tonsils; teeth are surveyed and treated if necessary, and a daily hot meal is served to the under-nourished pupil.
Modern medical discoveries have resulted in reducing the amount of internal medicine used, and in increased attention to diet, exercise, baths, diversion and rest and natural and hy gienic modes of life. Preservation of infant life, conservation of health by avoidance of morbific agencies and increase of longevity are the aims of medical practice to-day.
See BACTERIA; BACTERIOLOGY; CLIMATE IN TREATMENT OF DISEASE; DISEASE, GERM THEORY or ; GERM; IMMUNITY; OLD AGE, DISEASES OF;