HYGIENE. – Hygiene (from the Greek ὑγιεινή [technē], meaning “health”) may be defined as the science and practice of health. Its fundamental aim is the prolongation of human life through the physical and mental well-being of the individual and of the community to which he belongs; it seeks to achieve this end by conceiving, elaborating, and subsequently applying methods suited to the complete removal or at least the neutralization of harmful factors arising from the environment or from the various organic constitutions of individuals or from the structure of society itself.
From a broad perspective, one may distinguish within hygiene two principal branches: theoretical hygiene and practical hygiene. The former investigates the rationale behind measures to be applied according to well-defined theoretical principles; it constitutes a major branch of medical knowledge, which has developed notably in the wake of the fundamental microbiological discoveries and epidemiological observations of the past century. The latter, instead, derives from centuries of empirical experience and modern experimental and observational data the technical norms for implementing the postulates enunciated by theoretical hygiene.
The history of the idea of hygiene reveals epochs of remarkable progress alternating with periods of decline, which in calamitous times (famines, wars, pestilences) sometimes led even to the annihilation of the most elementary hygienic customs.
Thus, one may point to the Greek world as an incomparable master of hygiene, the first to make physical education of youth a veritable program of the State, aiming to achieve, through individual education, the most perfect harmony of body and mind within the community. Dietetics in Greece attained the status of a hygienic science, and many of the Hippocratic concepts that permeate modern doctrine informed an entire body of legislation from which emanated a clear public health program: street cleaning, provisions for potable water, food control, market regulation, mortuary police, baths, gymnasia, private and public buildings, etc. This is clearly documented by the fact that the development of hygiene ran parallel to the cultivation of the intellect.
The same may be said of the Roman world, with its grandly simple engineering of aqueducts, sewers, baths, and land reclamation, its general building works, and its codified organization for medical assistance to the population.
As the centuries unfolded, from the Greco-Roman world we descend to the High Middle Ages, its obscure heir, yet one that carried within itself the seeds of the Renaissance. Despite the decline in hygienic practices, it saw the first hospital foundations of the Byzantine East and the growth of monastic orders dedicated to the care of the sick; while the Schola Medica Salernitana preserved, in a most difficult period for scientific tradition, the medical-hygienic thought in its purest form. Meanwhile, the epidemics that ravaged the then-known world—and which had already given the Church occasion to concern itself with the health of populations (see below)—stimulated, particularly in the 14th and 15th centuries, in the mercantile republics, a rapid revival and progress in hygiene, concentrated in the elaboration of prophylactic health legislation that served as a clear paradigm for later similar laws. We then encounter the first treatises on individual hygiene (Taddeo Alderotti of Florence, Aldobrandino of Siena, Ugo Benzi), in which there re-emerges, alongside the concept of personal individuality, the awareness of self-defense as a member of the body politic.
The subsequent prosperity of industry and commerce in the Italian communes of the Renaissance, which saw their stable populations grow rapidly, led to the creation of social assistance institutions and the issuance of imperative norms that may today be considered the germ of future protective labor legislation. Unforgettable names in the history of hygiene are those of the great Italian scholars who, with the Renaissance and its pleiad, continue chronologically down to our own day: Fracastoro and Ingrassia in the 16th century—the former reviving the principle of the “contagium animatum sed vivum,” the latter an indefatigable organizer against the Sicilian plague; in the 17th and 18th centuries, Vallisneri, who likewise championed the contagionist theory, Ramazzini, the true initiator of modern social medicine and who established the principles of hygiene and the clinical study of occupational diseases; Lancisi, in whose brilliant observations are found the fundamental precepts that two centuries later would form the cornerstones of the anti-malaria campaign; Monsignor Gastaldi, special health commissioner of the Papal government, a brilliant and prolific legislator of the anti-plague campaign of the 17th century in Rome; Antonio Cocchi and Domenico Cotugno, through whose initiative measures for the protection against tuberculosis were issued in Tuscany; Giovanni Pietro Frank, who at the close of the 18th century set forth in a classical treatise, gathering them into a coordinated system, the most important doctrines of political hygiene, disciplining their provisions and affirming public health as their supreme basis.
Yet an even swifter acceleration of hygienic progress began in England on account of the cholera epidemic of 1830. That nation saw its maritime routes rendered unsafe by contagion and thus threatened its most vital economic lifeline. Hence a series of elaborate prophylactic laws concerning ships and landing ports. Likewise, the influx of the rural population into the great industrial and commercial cities of England made plain to that nation the necessity of regulating the hygienic problems arising from the growth of urban centers: hence a large number of “Health Acts” that constitute an important document of unparalleled evolution in the domain of public and private hygiene.
Meanwhile, in Germany too, a systematic organization of sanitary administration was taking shape, and there, as well as in France and Italy, a rapid succession of studies and research followed, which, starting from the practical successes of JENNER in smallpox vaccination, from the discoveries of Agostino Bassi (on the muscardine of the silkworm), of Pasteur, of Lister, and of many other illustrious figures, would lead to the present state of the fight against infectious diseases. At the same time, fostered by modern technology, all the other branches of hygiene developed as well, forming a "corpus" of knowledge and applications aimed at the social and economic well-being of nations.
Hygiene, following the progressive inclinations of peoples, like every other manifestation of human activity, has increasingly convinced man of the great benefits it provides. Today, this activity unfolds in correlation with the outcomes of scientific investigation and tends ever more rationally to procure and preserve for man and communities the best living conditions. It has taken its place among the biological and social sciences, and its importance is confirmed daily by the advantages enjoyed by civilized peoples: prolongation of human life expectancy, reduction in mortality and morbidity rates, increased productive capacity, etc. Having the duty to guarantee every individual in the community complete sanitary protection, to compensate for the insufficiency of individual self-defense means, hygiene has become a function of the State.