The enteritis rate for the smaller cities (less than 100,000) is even more accurate as an index of sanitary conditions, if we exclude waterborne enteritis. Table No. 11 shows the average rate for five years (1904-1908) for enteritis in cities with populations between 50,000 and 100,000. These may be divided conveniently into three classes: The first 15 have rates from 50 to 100; the second 15 have rates from 100 to 150; the third group of 13 have rates ranging from 164.7 in Schenectady, N. Y., to 342.3 in Charleston, S. C.

TABLE 11.-Enteritis, all ages, death rate per 100,000 in cities with a population from 50,000 to 100,000.

The first group of 15, with rates below 100, contains no city from the country south of the thirty-eighth parallel of latitude. Some eastern cities are in this group. They are not "mill" towns, however, but cities of quite a different type, as Somerville, Mass., Hartford, Conn., and Harrisburg, Pa.

The second group has cities from all sections. The rates 100 to 150 are too high for cities of this size, and an intensive study of conditions will show the special reason or reasons in each case.

Duluth's rate of 103 is higher than one would expect. St. Paul and Minneapolis have rates below 60; considering it climatically, Duluth should be no higher. There is no negro factor to raise the rate, but there is quite a large foreign population. South Bend, like Duluth, has very much higher rates than cities in the surrounding territory. Wilmington, Del., Savannah, Ga., and Mobile, Ala., have rates no higher than might be expected with the large negro population. The excessive rates in Group 3 are best explained by the insanitary conditions, maternal neglect, ignorance, and poverty of mill and factory towns. The last two cities are southern cities, and the explanation of their high rates is probably to be found in climatic and racial influences.

During this investigation of cities in the drainage basin of the Great Lakes, the writer was struck with the high rates for diarrhea and enteritis in some northern cities coincident with absence of slums and a polluted water supply, and the close relation existing between the rates for enteritis and typhoid fever. The following table shows 12 New York cities. The first 4 have good water supplies, good sanitary conditions, and low rates for both typhoid and enteritis. The second 4 have good water supplies, low typhoid rate, bad sanitary conditions (mill and factory towns), and high enteritis rates. The last group of 4 have polluted water supplies, fair to good sanitary conditions, high typhoid-fever rates, and high enteritis rates.

A similar relation between typhoid and enteritis was found in certain Michigan cities, although these coincidently high rates were not always associated with a polluted water supply.

The Michigan rates are for diarrhea and enteritis under 2 years, instead of for all ages.

TABLE 13.-Michigan cities, population from 12,000 to 50,000-Average deaths per 100,000 for six years, 1905-1910.

This table shows that in every instance, except Traverse City, a typhoid-fever rate above 40 was accompanied by an enteritis rate above 60. This is a high rate for these cities, considering climatic, racial, and social-economic conditions, as this rate is for enteritis under 2 years only. On the other hand, the cities with good water supplies had low rates for typhoid fever and enteritis, except Sault Ste. Marie, which will be referred to later.

Enteritis or diarrhea in children as a fatal disease may be expected to be excessively prevalent in large cities with slum districts and a large foreign population. The same excessive prevalence may be expected in so-called mill towns, where the mothers are employed in the mills and child neglect is common. Under these conditions the mortality among poor children is very great, but it is almost entirely in the period from July to October.

The relation between enteritis in children and typhoid fever can not be said to be clear. Certain facts, however, stand out prominently in studying the statistics. In cities which are too small to have slums and which have abnormally high typhoid-fever rates there is also an excessive mortality from enteritis and diarrhea in children under 2 years of age. Cities of the same class with low typhoid rates have comparatively low rates for enteritis and diarrhea of children.

The seasonal prevalence of enteritis also closely follows that of typhoid. If the excessive typhoid in these cities is due to water, then we have a high enteritis rate not only in the summer and autumn, but also in the winter and spring months. If the typhoid is independent of the water supply, then the enteritis rate, like that of typhoid, will be high in the regular season from July to October and low during the remainder of the year.

Instead of one disease designated under several different names we are probably considering several diseases with common factors of transmission. Whatever the real relation between typhoid fever and enteritis or diarrhea of children may be, one fact is clear, the same causes operate to cause excessive prevalence of both. It is probable that cases of typhoid in children under 2 years in many cities are often incorrectly diagnosed as enteritis. It must be remembered, however, that the causative agent of bacillary dysentery is transmitted in the same way and by the same media as that of typhoid. There are too many cases of fatal illness in children under 2 years classed as diarrhea and enteritis, and an exhaustive investigation should be made to establish the real cause of death in enteritis and diarrhea of children. Without such an investigation it is impossible to assign the real cause of the excessive child mortality from diarrhea and enteritis. In cities of less than 50,000 population without slums and which are not "mill" towns an enteritis rate

in children under 2 years above 100 deaths per 100,000 indicates prevalence of an acute intestinal disease preventable by the same measures which prevent typhoid fever. It is probable that in such cities proper enforcement of prophylactic measures against typhoid fever would reduce the enteritis rate below 40 deaths per 100,000. Enforcement of prophylactic measures would include the installation of pure water supplies and proper sewerage systems, coupled with a vigorous campaign against the insanitary outdoor privy and the equally dangerous shallow well.

THE SIGNIFICANCE OF TYPHOID FEVER FROM AN INTERSTATE

STANDPOINT.

The prevention of the spread of typhoid fever from one State to another is necessary to reduce the prevalence of typhoid fever in cities and States, so that the prevention of typhoid fever is a national problem and a local or State problem as well. The careless pollution by sewage in one State by town A of a stream used as a water supply without filtration in another State by town B is an illustration of interstate spread of typhoid fever which is common enough. In such an instance the town A polluting the stream insists that the town B below protect itself by filtering its water supply; B insists that the town A above should render its sewage inocuous before discharge into the stream. As a matter of fact, both may be indicated, and both of these great agencies for preventing water-borne typhoid may be necessary. It is difficult for these communities to adjust their differences and decide to just what point sewage purification must be carried at A in order that too great a strain and too great a responsibility may not be placed on the filter plant at B. This is clearly an interstate matter and should be decided by a Federal authority acting under Federal law.

The significance of polluted water supplies in large industrial centers from an interstate standpoint is enormous. Trains and steamboats take their water supplies at such points and this polluted water is drunk by the passengers throughout the trip. Common carriers in interstate commerce also contribute to the spread of typhoid in interstate traffic by failure to have their railroad trains and steamboats provided with retention tanks for excreta. Human excreta may in this way be deposited in streams used as water supplies or in lake water in the vicinity of waterworks intakes.

Excessive prevalence of typhoid fever in any city which by reason of its commercial or industrial importance attracts large numbers of visitors has an important bearing upon the spread of typhoid from one State to another. The same is true of other cities which because of great natural advantages, the beauty of their surroundings, or other reasons attract thousands of tourists and visitors from other

States. For these reasons the prevalence of typhoid and the character of the water supplies in cities like Pittsburgh and Detroit, Niagara Falls, or Mackinac Island become a matter of serious moment from an interstate standpoint.. The excessive prevalence of typhoid fever for years in Niagara Falls and Pittsburgh was not only a matter of local or even State concern, but a grave national danger as well. During the five years 1904-1908, inclusive, the Michigan State Board of Health traced the origin of 663 outbreaks of typhoid fever in all parts of the State. While the figures were compiled in order to compare urban and rural communities as places of origin for the spread of typhoid, the results throw an interesting sidelight on the spread of typhoid fever from one State to another. The outbreaks traced were all in Michigan, and the figures do not show the spread from Michigan cities to other States, but reciprocity in this respect is probably the rule. The Michigan statistics show that many outbreaks were traceable to Chicago, Toledo, and Indiana cities, and occasionally to Pittsburgh, Buffalo, Philadelphia, and Washington. The following table shows the number of times responsibility for outbreaks was placed:

To summarize briefly, 20 per cent of the new outbreaks were traced to other States, and generally to large cities, such as Chicago or Toledo. Nearly 12 per cent of the outbreaks investigated were traced to infection in Grand Rapids.

Grand Rapids is only one-fourth the size of Detroit, and yet the number of times typhoid was introduced into other localities from the former city was two and one-half times that of Detroit. The influence of Grand Rapids in spreading the disease to other States can be inferred, as the distance from Grand Rapids to Wisconsin, Illinois, or Indiana is not much greater than the distance from Grand Rapids to points in Michigan to which the infection was carried from Grand Rapids. It is disheartening to combat typhoid fever in a restricted area which is being fed constantly by streams of typhoid carriers and patients from other communities.