Rural Hygiene

by Henry N. Ogden

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.