Milk is a food that is in a class by itself, owing to its liability to undergo changes, develop unwholesome products, and become a spreader of disease germs. It may endanger public health to such an extent that the supervision and control of its production and distribution is exercised by hoards of health without question. But the same kinds of changes and infections that affect milk may affect other foods also. Various departments of national and state governments are undertaking certain phases of food supervision largely on economic grounds; and the departments of health of the larger cities are extending the work for sanitary reasons. The control of the sanitary conditions of foods, drinks, and confectionery that are offered for sale is under the jurisdiction of a local board of health, and the details of the supervision are within the scope of the activities of health officers and public health nurses. The word "food" is used in the general sense to include drinks, confectionery, and other substances which are ordinarily taken into the stomach.

The conditions which may affect the wholesomeness of food may be considered under four headings: 1, the state of the food itself; 2, the methods of preserving the food; 3, the health of persons who handle the food; and 4, the sanitation of the places in which foods and drinks are sold.

The conditions of food itself which may affect health are (1) its purity or freedom from adulteration, (2) its state of freshness or decomposition, and (3) the presence of poisons or disease germs.

Adulteration.—If a food has a composition different from that which it is purported to have, it is called an adulterated or sophisticated food. The conditions which are considered to be adulterations or sophistications are set forth in the Federal Food and Drugs Act of June 30, 1906 and are as follows:

1. Foods containing substances which are added in order to reduce their quality or strength, as, for example, watered milk.

2. Foods in which cheap substances are substituted for more expensive articles, as, for example, cottonseed oil for olive oil.

3. The meat of diseased animals, or foods containing filthy, decomposed, or putrid substances or products, as, for example, oysters contaminated with sewage, and eggs on the verge of decay.

4. Foods from which any valuable constituents have been removed, as, for example, skimmed milk. But the sale of such foods is permitted provided their actual nature or composition is stated on the labels or is told to the buyers.

5. Foods colored or otherwise treated in order to disguise damage or inferiority, as, for example, old meat colored red to resemble fresh meat.

The principal ground on which adulterations are condemned is that of fraud. A health department has no jurisdiction over adulterations on the ground of fraud alone, unless it is specifically authorized by law to act; hut it may properly take action when the adulterations have an effect on public health.

Freshness.—Many foods readily undergo changes in their physical state which render them undesirable as food without directly affecting their wholesomeness. Examples of loss of freshness are the wilting of vegetables, the softening of hard crackers during moist weather, and the lumpiness of old cornmeal due to the action of the oil of the corn. A department of health has little or nothing to do with this group of foods.

Decomposition.—The word "freshness" is also applied to the chemical state of food. A chemical change in food is usually called decomposition, and is nearly always caused by the growth of micro-organisms in the food. Decomposition is not necessarily a harmful process, and it is often applied in the manufacture of foods. Butter, cheese, and other dairy products are made with the aid of bacteria; bread is made light by the growth of yeast plants; sour bread is made by the action of yeast and bacteria; saucer kraut and pickles are products of bacterial action; and meat is improved in texture and flavor by the bacterial growth which takes place while it is hung in a cool room for a few days.

The processes of decomposition in foods may be divided into two main groups: 1, fermentation, or the change of sugars and starches to acids and gases, such as lactic acid in milk; and 2, putrefaction, or the change of proteins to alkaline products, many of which are offensive to the senses and poisonous. The products of the fermentation of sugars and starches are seldom harmful in themselves, but they are often associated with products of the putrefaction of proteins. When souring takes place in a food in which the production of acids is not a normal process, it may properly be considered to be an indication of unwholesomeness.

The ordinary decomposition or putrefaction of proteins gives rise to a class of poisonous products called ptomains. The usual symptoms of poisoning by the ptomains of decomposed food are abdominal pain, vomiting, diarrhea, fever, and weakness, and develop within a few hours or a day after the food has been eaten. The products of ordinary decomposition are not usually poisonous when their offensive odors and tastes first begin to be apparent, or when the process of decomposition is far advanced toward the final end-products. They are more frequently poisonous during the intermediate stages of decomposition, but their offensiveness is then so apparent that one instinctively shuns the food. A trace of t he peculiar odors and tastes which are associated with putrefaction may be considered to be danger signs of approaching unwholesomeness, and a food in which they are present may properly be condemned.

Specific Bacteria of Food Poisoning.—The severe forms of food poisoning are usually caused by specific bacteria which are not usually present in and around food, but which are transmitted by the contact of one parcel of food with another, or with a diseased person or animal. Food containing these organisms may be considered to be infected in the same sense that a culture-tube is infected when it is inoculated with diphtheria bacilli; or that a person with typhoid fever is infected with typhoid bacilli.

The specific bacteria of food poisoning belong to the paratyphoid group, and consist of many varieties, some of which are peculiar to human beings only, while others are peculiar to cattle, or to pigs, rats, mice, or other lower animals. Two characteristics which are common to all varieties of the bacteria are (1) the production of toxins and (2) the ability to grow in meat and other foods. The symptoms of poisoning in man may be caused either by the toxins that developed in the food before it was eaten, or by the growth of the bacteria themselves after they have been introduced into the human body. The bacteria may be present in an animal that was sick before it was killed, or they may be introduced into meat or other food by a human carrier or by contact with infected meat, or the infected dirt of slaughter houses or butcher shops. The bacteria which are peculiar to lower animals seldom grow in human, beings, but their toxins may produce the abdominal symptoms of food poisoning. The bacteria which are peculiar to mankind produce paratyphoid fever when they are introduced into the human body.

The bacteria of food poisoning are usually associated with putrefactive organisms which are present almost everywhere; but the substances produced by the specific bacteria are not usually unpleasant to the senses, and they may be present in dangerous amounts while the food is apparently fresh and in good condition. Most foods of animal origin are likely to become infected or to undergo natural decomposition much more readily than those of vegetable origin. The following is a list of the ordinary classes of foods arranged in the order of their liability to become infected or decomposed:

1. Milk.

2. Crustaceans (lobsters, crabs, etc.).

3. Shell-fish (oysters, clams, etc.).

4. Fish.

5. Meat.

6. Fruit.

7. Vegetables.

8. Cereals.

Investigation of Food Poisoning.—Since food poisoning often has the nature of an infectious disease, the investigation of cases is a duty of a department of health. It may be suspected when its symptoms suddenly occur in a group of persons who have used a particular article of food or have eaten together. The sanitary code of New York State requires that the existence of a group of cases shall be reported to the health officer and also to the state commissioner of health (Chapter 2, Regulation 41). When cases are reported, the procedures that a health officer is to take are as follows:

1. Search for a common article of food that has been used by all the affected persons.

2. Obtain a sample of the food, place it on ice, and send it to a laboratory for a bacteriologic examination and a determination of the type of its organism, if any be present.

3. Search for the primary source of the infection, which will probably be either a human carrier, or an unclean shop or store, or ice-box, or the carcass of a diseased animal.

4. Take the necessary steps for the control of the carrier, or the disinfection of the infected places, or the destruction of the diseased meat.

Sausage Poisoning.—A special form of food poisoning is t hat known as botulismus, or sausage poisoning. It is caused by the Bacillus botulisms. The bacilli do not grow in the living body, but grow readily upon many kinds of foods, especially the ground meat of which sausage is made, for the grinding will distribute the bacilli from a small focus through the whole mass. The bacteria produce a toxin which is extremely poisonous when it is taken into the stomach, but it is destroyed by the heat of cooking. The sources of the bacilli are unclean and infected shops and utensils. The disease may be prevented by cleanliness in food handling and by thoroughly cooking the food. While it is a rare disease, the possibility of its occurrence is an argument for the sanitary control of places for the sale of foods.

Preserving Agents.—The decomposition of food may be prevented to a great extent by the use of chemical preservatives. These substances are antiseptic, and often have a poisonous action upon the human body. Their use constitutes a form of adulteration which is forbidden by the Federal Pure Food and Drugs Act.

The feeding of civilized people could not be done according to modern standards unless large amounts of perishable food which are produced in seasons and places of plenty are preserved and transported for use in seasons and places of scarcity. The efficient methods of preserving food in a wholesome state are: 1, drying; 2, canning; 3, salting; 4, pickling; 5, smoking, and 6, cold storage.

The wholesomeness of preserved foods depends principally upon four factors, as follows:

1. Their conditions when they are preserved.

2. The cleanliness and care with which they were handled during their preparation.

3. The method of their storage.

4. The period of time during which they are kept.

The processes of preservation may conceal the true nature of foods to a great extent, and give many opportunities for fraud. There is a great temptation to preserve food of an inferior quality and that which is about to spoil, and to keep the preserved products for long periods of time until a profitable sale can be made. But if the preserving is done honestly, the products will be as wholesome as the fresh foods.

Cold Storage.—The process by which foods are preserved in their most natural condition is that of cold storage. The business is highly specialized, and each section of a warehouse is fitted for a single class of food. The temperatures vary from a few degrees above freezing, for fruit and eggs, to 10° F. or lower for meat and fish. The periods of time during which foods will keep fresh and wholesome are known with considerable accuracy. Some kinds of bacteria and molds will grow at temperatures below freezing, and some evaporation of water continually goes on. A year is about the limit of time during which the freshness and wholesomeness of cold storage food can be guaranteed.

When foods that have been properly preserved in cold storage are removed for sale, they are in the same state that they were when they were put in storage. Food about to decompose will quickly decay after it it removed from the warehouse, and food that is infected will remain infected. But food which is fresh and of good quality when it is put in cold storage will remain fresh and wholesome while it is in storage, and will keep fresh for a reasonable length of time after it is removed. The people of cities could not be fed without cold storage.

Canned goods are usually sold in tin containers. A can is sealed while hot, and on cooling a vacuum is formed and the ends of the can are forced inward by the pressure of the air. When fermentation or decomposition occurs, gas forms and relieves the vacuum or makes pressure within the can. The test for the freshness of foods in sealed tins is the degree of vacuum or pressure within the cans. An inspector divides abnormal cans into four classes: 1, swellers; 2, springers; 3, flippers; and 4, leakers.

An inspector will first notice the ends of a can. If they are convex, gas is present under pressure, and the can is a sweller and is to be condemned.

The inspector will press upon the end of a can. If the opposite end bulges out with a snap, the can is a springer and its contents have undergone some degree of fermentation or decomposition.

The inspector will strike the end of a can flat upon a table. If there is a small amount of gas in the can, the blow will cause the bottom of the can to bulge out and remain convex. If the convex end is pressed, it will spring back with a snap. A can that reacts to this test is a flipper and its contents are in the beginning stage of fermentation, although they may not necessarily be harmful to health.

A can that is evidently leaking is always to he condemned.

A health officer or housewife can readily apply these tests in detecting canned foods which are presumably unlit for food.

Disease Germs in Food.—Foods may transmit diseases to man by means of disease germs which either were in an animal before its slaughter or were introduced into the food.

Most diseases of lower animals do not affect man, but a few may be transmitted to human beings, among them being anthrax, glanders, vaccinia, rabies, tetanus, foot-and-mouth disease, trichinosis, tapeworm, and tuberculosis. Paratyphoid fever in cattle is of importance because of its relation to food poisoning. The principal animal diseases which have a relation to human food are trichinosis, tapeworm, and tuberculosis.

Tuberculosis is common among cattle and pigs. It may be detected by an inspection of the carcass and internal organs of the slaughtered animals. The signs of the disease are enlarged lymph-glands, tubercles, and abscesses. The enlarged glands are usually seen in the neck and around the lungs and the intestine. Tubercles are white bodies like pinheads scattered through the affected tissues, especially of the lungs. Abscesses are the result of a breaking clown of the glands and tubercles.

Meat Inspection.—The inspection of meat at slaughter houses by trained inspectors is a necessary measure for the protection of public health. The departments of health of the larger cities require that animals to be used as food shall be slaugntered at licensed slaughter houses in the presence of trained inspectors, but in rural districts animals intended for local consumption are often slaughtered without an inspection of the meat or of the houses.

An inspection is made of the living animals and also of their carcasses and internal organs. Living animals are condemned when they are evidently diseased or show signs of sickness. When a slaughtered animal shows signs of disease, its body and internal organs are laid aside and examined in detail later. If the disease is localized, the affected parts are removed, and the remainder of the carcass is usually allowed to be sold. There seems to be no sanitary reason for condemning any healthy edible part of an animal, since a thorough cooking will prevent the transmission of disease by the meat.

Food Infection.—The infection of foods with the bacteria of human diseases is of special importance when the foods are to be eaten raw. There are three principal sources of infection: 1, sewage; 2, contaminated water; and 3, human carriers. The foods which are most likely to become infected are shell-fish and green vegetables.

Oyster Infection.—The most prolific oyster and clam grounds are located in shallow bays and estuaries where the water is likely to receive sewage from houses and villages. These waters nearly always contain colon bacilli which are derived from the banks of rivers and creeks which slow into them. Oysters feed by extracting bacteria and other microscopic plants from the water which passes over their gills. The kinds of bacteria that are in the water will usually be found in the liquor which surrounds an oyster in the shell. Colon bacilli are nearly always found in this liquor, and the presence of a few is not considered to be abnormal or to indicate contamination.

A few outbreaks of typhoid fever have been caused by eating raw oysters and other shell-fish taken near the mouths of sewers or in water that is heavily contaminated with sewage. The likelihood of the infection of oysters with typhoid bacilli is in direct proportion to the contamination of the water with colon bacilli. The principal cause of the infection with typhoid bacilli has been the practice of placing oysters in the mouths of fresh-water creeks which often contain sewage. This was done in order to make them appear plump because of the entrance of fresh water into the salt flesh of the oyster by the process of osmosis; but the practice is no longer legal, for the plumping simply dilates the flesh with water, and it may produce contamination of the oyster.

While the temperature of the water is below 40° F., oysters keep their shells closed and remain in a state of hibernation. During this period they soon digest the bacteria that lie within their shells, and remain sterile until the temperature of the water rises above 40° F. Since oysters are usually on the market during the cold months only, their hibernation is a great protection against infection.

The sanitary standard of oysters is based on the presence of colon bacilli in various amounts of their liquor. Five oysters are chosen from a lot, and three cultures are made from each. One c.c. of the liquor is taken for the first culture, 1/10 c.c. for the second, and 1/100 c.c. for the third. If colon bacilli are found in the 1/100 c.c. sample, the score of the oyster is 100. If they are found in the 1/10 c.c. and not in the 1/100 c.c., the score is 10; and if in the 1 c.c. only, the score is 1. Allowance is made for the chance that colon bacilli might be found in a 1/100 c.c. sample when there are only one or two present in each cubic centimeter of the liquor. A maximum total score of 50 is allowed for the five oysters. This practically means that oysters are considered wholesome when colon bacilli are found in each 1/10 c.c. of their liquor if they are not found frequently in 1/100 c.c. samples.

Cooking is an efficient preventive of infection from eating contaminated oysters.

Vegetables which are eaten raw may become infected with typhoid bacilli when they are fertilized with sewage or human excretions, or are washed in contaminated water, or handled by a carrier.

Infection from Food Handling.—Persons who are afflicted with communicable diseases, or are carriers of disease germs, may introduce disease germs into foods which they handle. Foods may be divided into three classes according to their likelihood to transmit infection from those who handle them to those who eat them:

1. Foods which are to be cooked before they are eaten are not likely to transmit infection.

2. Foods which are to be eaten raw are possible sources of infection, but are not likely to be dangerous provided they are properly cleansed.

3. Foods in kitchens and those which are ready to be served at table are likely to transmit infection from infected cooks, waiters, and clerks. Soups, meat broths, stews, and boiled potatoes are similar to the culture-media used in laboratories, and when they are infected, bacteria of disease may grow in them readily. Lunch counters, restaurants, delicatessen stores, and other places in which food is sold ready to be eaten spread diseases far more readily than butcher shops, groceries, and similar food stores in which most of the foods sold are cooked or cleansed before they are eaten.

The principal diseases which are transmitted by means of foods are those of the intestine, especially typhoid fever. Cooks have been known who have been spreaders of typhoid fever for years, and have produced cases in nearly every place in which they work. These carriers may be detected by modern methods of laboratory examinations of their excretions.

Diseases of the throat and respiratory organs may also be transmitted by means of foods which are handled by infected persons or carriers. The best known examples of diseases which are food-borne are septic sore throat, diphtheria, and scarlet fever by means of milk; but any other cooked food may also transmit the diseases.

Prevention.—The prevention of food infection and of food-borne diseases consists in:

1. The education of the public.

2. The inspection of places in which food is prepared and sold.

Public education regarding food-borne diseases may be conducted along two general lines:

1. Instruction regarding the preparation of foods so as to destroy whatever infection that may be in them.

2. Arousing the public to demand cleanliness and sanitary methods of handling foods in places in which foods are sold. Financial loss from lack of trade is an effective means of influencing food dealers to adopt sanitary methods of food handling.

Food Inspection.—An ideal system of food inspection will embrace every stage of the production of a food from the crude article to its delivery to the consumer. The most practical system for an ordinary board of health to adopt is that of inspecting foods when they are ready for delivery to the customers. The inspections will include restaurants, lunch counters, ice-cream parlors, soda-water fountains, oyster houses, candy shops, delicatessen stores, and other places in which foods, drinks, or confectionery are sold.

Inspector's Score Card.—An outline of the items to be noticed during an inspection is contained in a score card, called the United States Standard Score Card. The card was designed for the use of the officers of the United States Public Health Service, and is similar to that used in inspecting dairies. The figures on the score card may be criticized on the ground of the impossibility of assigning fixed values to conditions which are variable; hut the items constitute a standard guide for the inspection of any place in which foods, drinks, or confectionery are sold. An inspector is also to note the surroundings of an eating or drinking establishment, and to condemn those which are located near a stable or open cesspool, or privy, or other gross source of infection.

Examination of Food Handlers.—It is important that no person who is afflicted with a communicable disease, or is a carrier, be allowed to work as a cook or kitchen helper, or waiter, or to serve foods, drinks, or confectionery. While carriers are few in number, yet the danger from them is so great that extensive investigations for their detection and exclusion from eating houses are justifiable. Those who are grossly affected, or have open lesions, may be discovered by a physical examination; and those who are carriers may be detected by a bacteriologic examination of their excretions. Boards of health are beginning to require a medical examination and certificate of freedom from communicable diseases from workers in restaurants; and boards in the larger cities are requiring a bacteriologic examination of their excretions.

Sterilizing Dishes.—Dishes in which foods are served to patrons and the utensils with which they are eaten are contaminated with the excretions from the hands, mouths, and noses of the customers. The only practical method of sterilizing them is by the use of boiling water. A simple method of sterilizing them is to wash them in the ordinary way in soap and hot water, and then place them in a wire basket and dip them into a large kettle of boiling water which is kept on a stove for that special purpose. Dishes which are dipped in boiling water require no wiping, and thus they escape contamination from extra handling and from soiled towels which are often used in drying them. The economy of help required more than compensates for the expense of the fire.

The glasses and dishes at soda-water fountains and ice-cream parlors are often cleansed by placing them over upright brushes through which cold water flows. These brushes cannot be kept sterilized, or even clean, and are often sources of gross contamination unless the utensils are afterward dipped in boiling-water. The use of paper containers is an economic sanitary method of serving cold drinks and ice-cream.

Food Regulations.—The presence of large camps of laborers engaged in building army cantonments has aroused the civil population to the necessity of food regulations similar to those which are adopted in armies. A simple code is as follows:

No food or drink, or material for making food or drink, shall be sold unless it is kept and dispensed in clean, closed sanitary containers, and is handled in a clean and sanitary manner.

No food or drink shall be sold or exposed for sale unless it is kept covered in such a manner that it is protected against flies and dust.

No person whose hands or clothes are in an unclean condition shall handle or dispense food or drink that is exposed for sale.

No food or drink shall be sold or exposed for sale in stores, stalls, or wagons which are in an unclean or unsanitary condition.

No food or drink shall be sold, or offered for sale, or dispensed in dishes which have been previously used, unless the said dishes shall have been adequately cleansed with boiling water.

Frank Overton

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