Infectious Disease.—Local health authorities have been en trusted with important duties in regard to the prevention and control of infectious disease and have developed elaborate ma chinery for this purpose. The Infectious Diseases Notification Acts of 1889 and 1899 made certain of the commoner infectious diseases notifiable to the Medical Officer of Health and gave local authorities power to add to their number where it seemed neces sary and expedient to do so. Since then other diseases have appeared in epidemic form, such as cerebrospinal fever, anterior poliomyelitis (infantile paralysis), encephalitis lethargica (sleepy sickness), and the central department, acting under authority of the Public Health Act 1875, has made these diseases notifiable by regulation and prescribed the measures which should be taken for their prevention and control.
The measures adopted by a local authority to control the spread of an epidemic disease are briefly,—isolation of the patient, either in the home or, where this is not practicable, in hospital; search for the source of infection; observation of the contacts ; disinfection; and, where an efficacious vaccine is available, vac cination.
Under the authority either of the Public Health Act 1875 or of the Isolation Hospitals Act 1893, most local authorities have provided hospital accommodation for cases of infectious disease occurring in their districts.
It is obvious that infectious diseases which are indirectly transmitted through the agency of some medium such as water, milk, food, flies, etc. are more easily prevented than those which are spread directly from person to person, and the measures that are applicable to the one do not always prove successful in the case of the other. For this reason typhoid, cholera, and other intestinal infections which formerly exacted such a heavy toll of life, no longer cause health authorities serious anxiety. In the same category one may place malaria, typhus and other insect-borne diseases. The diseases which are conveyed by personal infection, such as scarlet fever, diphtheria and the various epidemic nervous diseases, are much more diffi cult to control. The infection of many of these maladies is very widely spread throughout the community and many persons con tract the disease in what may be called a sub-clinical form without being conscious of it. The occasional clinical cases are often merely the apex of a considerable pyramid of infection, the greater part of which is submerged and unrecognized. One of the great problems of preventive medicine is to elicit the factors which determine these periodic clinical or epidemic manifestations of an infectious disease. Various theories have been propounded, but none of them is entirely satisfactory. Other diseases, such as tuberculosis, have a dual character, i.e., they may be transmitted directly from person to person or may be conveyed through the medium of some food such as milk or infected meat. Tuberculosis is a disease of great economic importance because the chief burden of mortality falls on the middle or productive years of life. It is for this reason that special measures have been taken to combat it in the form of notification, dispensaries, sanatoria and the other machinery established under the Tuberculosis Regulations. Some what similar measures, suitably modified, have been devised for the prevention and treatment of venereal diseases.
The most important measures dealing with food inspection are the various Sale of Food and Drugs Acts 1875-1907, the Public Health (Regulations as to Food) Act 1907 and the Milk and Dairies (Consolidation) Act 1915. Under these powers regulations have been made by the Central Authority deal ing with such subjects as milk and cream, meat, shellfish, imported food, preservatives and the prevention of tuberculosis. To a country which imports a large proportion of its meat from abroad it is very important to have some means of supervising production at the source. Agreements have been entered into with the chief producing countries by which these countries undertake to inspect and stamp all meat intended for export to England. This reduces the inspection necessary on arrival. A certain amount of inspection is carried on both at the ports and at the chief distribution centres in order to ensure that the producing country fulfils its undertak ing. The results of this method of control have been extremely satisfactory and every opportunity is taken to extend the system.
The local sanitary authority exercises supervision over the quality of the food distributed in its district and the conditions under which it is stored and sold to the public. For this purpose officers are appointed for the inspection of slaughterhouses and dairies, and samples of food are regularly submitted for analysis.
The introduction of compulsory education made it apparent that many children were unable, through ill-health, to benefit from the education facilities provided. This led to the establishment of the medical inspection of school children in 1907 and the gradual evolution of the present School Medical Service. The most important statute dealing with this subject is the Education Act of 1921 which re-enacts and amplifies previous powers and imposes on local education authorities the duty of making adequate and suitable arrangements for the medical inspection and treatment of children attending public elementary schools and also the medical inspection of scholars attending secondary schools. Education authorities are also re quired to make special provision for blind, deaf, defective or epileptic children.
This systematic inspection has revealed a vast amount of un suspected disease and minor defects which, if left uncorrected, lead in time to serious crippling. It is estimated that out of a total school population of some 7 millions, over a million children require medical treatment, apart from uncleanliness and dental diseases. The seeds of much of this ill-health are sown before the children enter school, a fact which emphasizes the importance of the pre-school welfare work which has already been referred to. On the other hand, the full fruition of school medical inspection can only be assured by continuation of the supervision during the critical transition years of early industrial life. Here the ad vantages secured by the National Health Insurance Acts of 1911 1924 are becoming apparent. With certain exceptions these pro vided for compulsory insurance against sickness of all employed persons between the ages of 16 and 7o. (For further industrial welfare measures see INDUSTRIAL WELFARE AND MEDICINE and