The two diseases already described, tuberculosis and pneumonia, are by far the most serious of all the infectious diseases, being responsible in New York State alone, in 1908, as already stated, for 5727 deaths. No other infectious disease even approximates the virulence and deadliness of these two, and while some of the constitutional disorders, such as Bright's disease, diarrhoea, and irregularity of the circulation, each result in from 2000 to 3000 deaths, the cause and prevention of these are so little understood as to baffle the hygienist. There are a number of contagious diseases which, while comparatively unimportant in the number of deaths, yet are of concern because the cause of the disease is so well known that the means of prevention is quite within our power. Of these, typhoid fever, in New York State in 1908, among the rural population alone resulted in 437 deaths, a rate of 18.7 per 100,000 population. The facts substantiate the assumption that for every person dying with typhoid fever there are ten cases of it, so it is a fair statement that in the rural part of New York State, in 1908, there were not far from 5000 persons afflicted with this disease.

Perhaps one of the reasons why so determined a fight against this particular disease, involving only 5000 cases of illness during the year, has been made, is on account of the length of the illness in each case and on account of the fact that the disease usually attacks those in the very prime of life, from 15 to 40 years. It is also to be economically considered by reason of the loss of time involved in an illness of nearly two months and the loss of money implied in the nursing, doctors, and medicine. The movement against the disease is most encouraging because the line of attack is well known, and there is, humanly speaking, no reason at all why the disease should not be stamped out.

Cause of the disease.

Typhoid fever is a modern disease, and only for the last fifty years has it been recognized in medicine. It is caused by bacteria, and its manifestations are the results of bacterial growth in the body, chiefly in the smaller intestine. Here the toxin produces a violent poison which results in an attack of fever, lasting about six weeks. Owing to the bacterial growth, serious failings, commonly known as perforations, may develop after a severe attack, in the membranes and linings of the intestine, and the resulting inflammation is not infrequently the immediate cause of death. It is a thoroughly established fact that the disease is caused by a special type of bacteria and that if the bacteria could be killed outside the body, no transmission of the disease could occur. It is also true that if the disease germs could be destroyed within the body the patient would recover immediately, provided the toxins had not been already distributed through the system.

There are, therefore, two possible methods of doing away with typhoid fever, one by eliminating all possibility of transmission outside of the body of the patient and the other by killing the germs while in the body of the patient. The latter plan is not feasible, since no antiseptic has been found which will kill the germs without killing the patient. It has been discovered that a drug called utropin will act on the germs when located in certain parts of the body, as in the kidneys; but this drug, although very effective in destroying germs in those organs, has no effect elsewhere. In general, we must eliminate the disease by preventing its transmission from the sick to the well.

The bacillus of typhoid.

Unfortunately, the typhoid fever germ is comparatively hardy and is not so easily killed by unfavorable environment as is the germ of pneumonia, for instance. It lives in water and in the soil, although probably it does not increase in numbers in either place. Nor will it live in the soil or in water indefinitely, and a great deal of study has been expended in trying to determine just how long typhoid fever germs will live under different conditions. It has been found, for example, that drying kills the typhoid bacillus in a few hours, although a few may survive for days. Experiments have also shown that it cannot leave a moist surface. It cannot, for instance, jump out of cesspools and drains and take to flight through the air, conveying the disease.

There is no possibility of contracting typhoid fever because a drain near the house is being cleaned out, since, so far as is known, the typhoid fever germ does not get into the air. The direct rays of the sun will kill typhoid fever germs within a few hours, although the value of this sort of disinfection is limited, because where typhoid fever germs are apt to accumulate, the turbidity of the water prevents the penetration of the sun's rays for more than a few inches.

It has been found that a high temperature kills typhoid fever germs, and even so moderate a temperature as 160 degrees Fahrenheit is sufficient to destroy them. This is the principle employed in pasteurizing milk, since it is assumed, justly, that by raising the temperature of the milk to 160 degrees Fahrenheit, for ten minutes, it will be possible to kill any typhoid fever germs present. Boiling, of course, since this involves a temperature of 212 degrees, will kill the germs, and it is for this reason that wherever a water is suspected of typhoid pollution, it should be boiled before being used for drinking. It has been found that in distilled water, that is, in water where no available food is to be had, the germs will live about a month, and that in water with organic matter present, but without other bacteria, this period may be extended two or three times. In water rich in organic matter, but where other antagonistic bacteria are also present, the typhoid germs are usually driven out or killed at the end of three or four days.

It is not unreasonable to expect that at least half of the germs discharged into a stream will live a week, and if the stream has a uniform current, so that the germs are continuously carried downstream, they will be found below the point of infection, a distance equal to that which the stream will flow in a week. This is important because it shows how unlikely it is that the germs once placed in water will die out or disappear without infecting those who subsequently drink the water. There is evidence that the typhoid germs, like all other germs for that matter, are likely to settle to the bottom of a lake or pond, and so a stream passing through a pond will lose a large part of the bacterial pollution with which it entered. This is not positive enough, however, to insure a good water-supply, since in the spring the heavy flow of the stream will wash this deposited material out through the pond, carrying the infectious matter downstream. In addition, the upheaval of the settled material from the bottom of the lake, which occurs twice a year on account of the variation in temperature at different depths, will bring the settled germs to the top.

It has been found also that just as a high temperature destroys the germs, so a low temperature has the same effect. Typhoid fever germs in ice are practically harmless after two weeks, and since in natural ice the impurities of the water are largely eliminated mechanically, so that frozen water is purer than the water itself, there is very little chance, even when ice is cut from a polluted pond, for typhoid germs to be found alive after being in an ice house for three or four months. In the ground, the life of the bacteria is longer, and while experiments do not agree very well as to the exact length of time that the germ may live there, there seems to be evidence that they may live several months, if not a year or more. Cases have come under the observation of the writer which seemed to show that certain well waters were polluted by germs which could only have been deposited in the near-by soil nearly a year before the time of the consequent outbreak.

Entirely to deprive the germs of life, therefore, it is necessary, inasmuch as they are so widely distributed, to act promptly and at once disinfect the fecal discharges from the patient rather than to wait until those discharges have been thrown into a stream or onto the ground and then attempt disinfection. There is probably no more important thing in stopping the spread of typhoid fever than to practice carefully disinfection in the sick room, using bichloride of mercury and chloride of lime, as already described in Chapter XV. Since, however, such disinfection is not always practiced and since care must be taken to avoid the introduction of the germs into the system, it is well to know how, assuming that they have not been killed in the sick room, they make their way from that place to a healthy individual.

Methods of transmission of typhoid.

There are three main avenues used by the germ, namely, water, milk, and flies, and of these three, the first is by far the most important and includes probably 80 per cent of all the cases. The reason for this is twofold. First, that water is so universally used, and second, that it is so easily and generally polluted. There are many historic examples which show definitely that water once polluted by typhoid germs is able to spread the disease far and wide.

The epidemic in Ithaca, New York, is a good example and ranks as one of the most serious that this country has ever known. The water-supply of the city is taken from a small stream, Six Mile Creek, which is a surface water with a drainage area of about 46 square miles. The stream is polluted to a large extent. About 2000 persons live on the watershed, and there are many houses practically on the bank of the stream which runs for a large part of its course at the bottom of a valley with steep side slopes. At the time of the epidemic, 1903, a dam was being built on the stream about half a mile above the waterworks intake, and while no proof of the fact could be found, it was generally supposed that some of the Italians working on the dam were affected with typhoid fever and had polluted the water. However, there were on the banks of the stream, farther up, no less than seventeen privies, and it was known that there were at least six cases of typhoid fever during the season just previous to the epidemic. During the month of December, 1902, a heavy rain occurred, so that any pollution on the banks would naturally have been washed down into the stream. On the 11th of January, the epidemic broke out through the town and by the middle of February there were some 600 cases reported in a population of 15,000. The number of deaths from this epidemic was 114, and there is reason to suppose that the number of cases was double the number reported by the physicians. After the water from the creek was shut off and after the citizens had been persuaded to boil all water used, the epidemic stopped and the installation of a filtration plant has prevented any recurrence of the epidemic.

In 1880, a severe epidemic occurred in Lowell, Massachusetts, and was traced to an infection of the river from which the city's water-supply was taken. This was definitely shown to have come from a small tributary of the Merrimac River, and the particular infection responsible for the epidemic was traced to a small suburb named North Chelmsford, where one case of typhoid fever occurred in a factory, the privy of which was located directly on the bank of the small tributary.

In 1900, an epidemic of typhoid occurred at Newport, Rhode Island, through the pollution of a well, and about 80 persons were affected, most of whom lived within a radius of 300 feet of the well and all of whom used the well water. The well was a shallow one with dry stone sides and a plank cover, and surrounding the well were about 20 privies, the nearest one only 25 feet away. The water in the well was 2 feet below the surface of the ground. It was found that a month before the epidemic broke out, there had been cases of typhoid fever in houses adjacent to the well, and that discharges from the typhoid patients found access to the privy vault which was only 25 feet from the well. It was practically certain that the well was infected by the leechings of these privies, particularly from the one only 25 feet away.

Another example of the way in which underground waters, such as springs, may become contaminated is described by Whipple as occurring at Mount Savage, Maryland, in 1904. Through this village ran a small stream known as Jennings Run, which was grossly contaminated with fecal matter. In July, 1904, a woman who had nursed a typhoid patient in another town came home to Mount Savage, ill with the disease. She lived in a cottage on the hillside above the stream, and the drainage of the cottage was conveyed through an iron pipe onto the ground just above the stream. Figure 77 (after Whipple) shows the relative positions of the cottage and stream. Heavy rains occurred during the first week in July which probably washed the infectious matter from the ground into the ditch and then through the ground into a spring just below down the slope. A week afterwards twenty workmen who had been drinking water from the spring came down with the fever and new cases occurred daily for a week or two.

An interesting epidemic occurred in Massachusetts, caused by a farmer's boots carrying infectious matter from recently manured fields onto the well cover, whence it was washed into the well by repeated pumping.

The moral of these incidents is very plain, namely, that where any possibility of the infection of drinking water occurs, that water ought either to be avoided or else to be thoroughly sterilized before using. This applies particularly to the old-fashioned well,—the kind with loose board covers and chain pumps.

Construction of wells in reference to typhoid.

Two points already mentioned are essential if well water is to be kept pure. One is to line the well with a water-tight masonry lining, and the other point is to have the cover of the well made with a thoroughly water-tight coating. This does not always give full protection, since in some cases polluting matter may pass through even ten feet of soil. This would be particularly true if the well was in a fissured or seamed rock, and very recently the writer found a well dug in a laminated granite, where a near-by sewer, leaking at the joints, contaminated the water of the well, although the well was cased with an iron casing twenty-five feet deep. The sewage escaped into a crack in the rock and followed the crack down vertically and horizontally into the well. Limestone is even more dangerous if any pollution exists in the vicinity. In cases where a well goes down to a horizontal layer of limestone and where a privy vault is dug to the same rock, it is found that pollution will follow the surface of the rock horizontally a long distance, and this condition of things always makes a well water suspicious. In sand or fine gravel, on the other hand, the danger of contamination is almost negligible; on Long Island, for example, the cesspools and well are both dug ten or fifteen feet deep and only fifty feet apart without any trace of contamination being detected.

Milk infection by typhoid.

Milk is responsible for perhaps 5 per cent of the cases of infection. Although the infection is always foreign to the milk itself,—that is, enters the milk only after the milk is drawn from the cow,—milk frequently becomes infected because infected water has been added to it or because the cans have been washed in infected water, or because some persons in contact with a typhoid patient have had their hands infected and then handled the milk or the milk utensils. There are a number of epidemics which have been clearly traced to milk polluted in one of these ways. In Somerville, Massachusetts, for example, in 1892, 32 cases occurred, 30 of which were on the route of a single milkman. It was found that the milkman had two sons, one of whom had typhoid fever just before the outbreak. This son washed the milk cans and mixed the milk in a milk house in the city, and the inference was that in some way this man infected the milk, probably in one of the mixing cans.

In Stamford, Connecticut, in 1895, an epidemic occurred which caused 386 cases and 22 deaths. Ninety-five per cent of all the cases occurred among those who took milk from one dealer, and it was probable that in this case the infection came from using a badly polluted water to wash the cans. In Montclair, in 1902, a small epidemic involving 28 cases occurred, where the health officers decided, after having found out that the cases were all among those customers taking milk in pint bottles, that the infection came from a house on the route, where typhoid fever had occurred. It appeared that this family infected the bottles left at their house, and since the milkman failed to sterilize the bottles before re-filling them, the infection was passed on to others also taking milk in pint bottles.

Infection by flies.

Flies also transmit typhoid fever chiefly because they are essentially such unclean insects. They are born in filth and they delight in living in filth, and if privies and cesspools and manure piles and garbage piles could be shut out from flies, the fly pestilence would be at an end. The feet of the flies are suction tubes, and when a fly lights on any object, it causes more or less of that material to stick to his feet, and then when he flies elsewhere, he may leave the particles on the object on which he alights. This has been proved by allowing a fly, caught in the house of a typhoid fever patient, to walk over a gelatine plate, leaving on the plate not merely his tracks, but the germs which his feet had carried. When the plate was exposed in an incubator, it was found that, within two or three days, millions of bacteria had grown from the number deposited by the one fly.

It is believed that the number of cases of typhoid which occurred in our Spanish-American War, at the military camps, and which were so disastrous, were due largely to flies. Among the 107,973 soldiers quartered in military camps at that time, there were 20,738 cases of typhoid fever, and the number of those which were fatal constituted 86 per cent of all the deaths from disease during this campaign. It was shown by the commission appointed to investigate the matter that the spread of the disease was not due to water or to food, but in most cases to the direct transmission of the germs through the agency of flies. In the Japanese and Russian war, where in the Japanese army of over a million men only 299 deaths from typhoid occurred, strict measures were taken to do away with all the breeding places of flies, and Major Seaman, who writes most interestingly on the success of the Japanese in avoiding typhoid, describes the ways in which the Japanese soldiers made flycatchers of themselves and waged war against flies quite as actively as against the Russians.

Other sources of typhoid fever.

There are other sources of the disease; for instance, there have been a number of small epidemics undoubtedly caused by infected oysters. One of the unpleasant habits of the oystermen is to bring in oysters from the ocean and leave them for a few days in shallow water where they may plump up or fatten, and they have found by experience that this fattening occurs more rapidly in dirty water. If the oysters are fattened in sewage-polluted water, the typhoid germs get inside the shell in the oyster liquor and are thus transmitted to those persons who eat the oysters raw.

Some kinds of food may transmit the disease: lettuce and celery, for instance, if washed in contaminated water or handled by persons with unclean hands or perhaps fertilized with manure containing typhoid germs. Finally, it is possible to acquire the disease by direct contact—not that the germs of typhoid are in the air in the room where a typhoid fever patient is lying, but rather that the nurse in some way soils her hands and then infects herself by putting her fingers in her mouth, or handles dishes or food afterwards used by other people, and so infects those others. It is not uncommon, for example, to see food partly consumed by a sick person given to children, or it may be that a child in the sick room is fed dainties prepared for the use of the patient. The result of such division of food is very apt to be a division of the sickness to the injury of the child.

Treatment of typhoid fever.

So far as present knowledge extends, the disease is one best treated by being let alone, with some moderate modification. When germs have been swallowed and when the vitality of the individual is such that the disease is contracted (happily, as has already been said, only about 10 per cent of those into whom the germ effects an entrance are inoculated), the first stage in the disease is a multiplication of the germs. This constitutes what is known as the incubation period, and lasts about ten days. During this time, the individual feels uneasy, has more or less headache and backache, and loses mental energy. The typhoid bacillus during this time spreads into almost every organ and tissue of the body, and towards the end of the period, when the resisting forces of the body have been proved unable to counteract the attack and the fever is well developed, the condition of the patient is deplorable. The bacteria are everywhere throughout the system, although they are especially active in the small intestines. This inflammation may produce ulceration and the blood vessels may be attacked, so that hemorrhages or even peritonitis may occur. A slight rash appears on the body, and a peculiar appearance of the tongue is to be found in severe cases. In from two to four weeks, the battle has been decided, and if the resisting forces prevail, the fever stops, and the patient begins to get well. This means probably, not that the bacilli are all dead, but that the patient has developed in his blood a sufficient antidote to the poison, so that the effects of the latter are no longer noticeable. The period of recovery, if the patient does recover, is most tedious, since the condition of the alimentary canal is such that great care must be exercised lest serious disorders there occur, and, although the patient is excessively hungry and really in great need of nourishing food, no greater folly can be committed than in allowing his desire for food to lead to indiscretion.

Injudicious exposure or fatigue will also cause a relapse, and while recovery is usually a simple matter, it is only so when under the eye of a judicious and careful nurse. The only treatment required is plenty of water for drinking, to make up for the enormous loss by perspiration from the skin, which helps to wash out the poisons from the body. Then baths, where such methods of treatment can be used, as in hospitals, are also used both to lower the skin temperature and to add water to the surface. Sponge baths in water or alcohol are valuable and in some cases tub baths with the temperature as low as 40 degrees are used. Then a proper diet to keep up the strength of the patient, liquids always, and usually milk, forms the only other treatment possible. No drug is of any avail, and uninterrupted watchful care is the only way of combating the disease.

In concluding this chapter, it may be mentioned that certain army officers interested in medical work have discovered what they believe to be an antitoxin for typhoid fever, and they have inoculated hundreds of soldiers as a preventative. The results are not yet conclusive, but there seems to be great promise. It is hoped that the time may come soon when people will be so educated that there will be no opportunity of the germs escaping from the sick room, and that food and drink will be so cared for that there will be no possibility of infection. The writer feels that it is in these last two methods of prevention rather than in the use of antitoxin that the hope of the future lies.