The following is a table showing the dates of onset, as nearly as could be ascertained, of the cases occurring in September and October:

Taking the total number of cases occurring since June 1, cn some of which only partial data could be obtained, it is found that 49 used the city water exclusively, 21 used both well and city water, while only 4 used well or spring water exclusively. Of the total of 73 cases, 11 gave a clear history of contact. Thirty-nine, or more than onehalf, denied the use of milk altogether. Forty-four were males and 29 females.

A careful epidemiological study was made of 30 cases, sick or convalescent at the time of my visit. The physicians very willingly took me to see their cases, all of which were, clinically, typical typhoid, a number being very serious cases, such complications as hemorrhage and double parotitis being noted. Widal's were made in several cases; all were positive. Of these 30 cases studied 8 were under 10 years of age; 9 between 10 and 20 years; 9 between 20 and 30 years; 2 between 30 and 40 years; and 2 between 40 and 50 years; 20 were males and 10 females; 5 were clearly contact cases.

One case was almost surely a milk infection, having drunk milk supplied by a neighbor who nursed her own daughter and milked the cow from which this case was supplied with milk, this being the only person to whom she supplied milk.

Eleven patients denied the use of fresh milk in any form, and 19 used milk as a beverage or in tea and coffee, but their milk supply was derived from various sources.

An attempt was made to ascertain the use of ice cream and raw vegetables and fruits, but while a majority had been in the habit of eating ice cream and raw vegetables and fruits, the source of supply could not be located with sufficient accuracy to be of any value.

In only 11 cases was there modern plumbing in the houses, and while at the time of my visit there were but few flies, the usual testimony was that they had been numerous during the summer.

The general sanitary condition of the houses visited was fair to good in 19 and poor to very poor in 11.

All of these cases derived their drinking water from the city mains, either wholly or in part.

From the foregoing it appears that the only common cause to which any considerable majority of these cases was exposed was the known polluted water. Eleven contact cases and one milk case seem to be fairly well established.

It is probable also that some cases may have been caused by flies, which were numerous during the month of September, but which were not numerous after the first week in October. There is a possibility also that some cases may have been caused by infected well water, but it is believed that the epidemic is traceable to the city

water.

The distribution of the disease in the town was very largely in the southern portion, only 8 cases out of 73 having occurred in that portion of the town north of Central Avenue, and at least 2 of these were traced to the use of city water in the southern part of the town at Oleson Park. One of these cases is particularly instructive:

R. W., age 9, the daughter of intelligent and well-informed parents, who, fearing the city water, had carefully prevented her drinking any but boiled water. August 18 to 25 a Chautauqua meeting was held in Oleson Park, many citizens, including the W. family, camping on the grounds; R., with other children, drank from the newly erected drinking fountain in the camp grounds. She returned to her home and became sick with definite symptoms of typhoid fever September 5, the probable date of onset being given as September 1.

On October 14 the city authorities, on the advice of Prof. Kinney, State chemist, instituted hypochlorite treatment of their water supply. The last but one case reported had its onset not later than October 26. The one exception was a clear contact case, having onset November 1, and is not included in the total of 101 cases, my record closing with October. Six cases among workmen of the Illinois Central Railroad roundhouse, where they drank from a neighboring well, elicited considerable local comment as to the probability that the well was the source of infection, but these men all drank city water at their homes, and no member of the family using the same well as an exclusive water-supply source contracted the disease.

The epidemic is charged to the city water for the following reasons: First. Known sewage contamination of the water.

Second. Sixty-nine out of 73 cases had derived their drinking water, in whole or in part, from the city mains.

Third. There was no other known factor common to a majority of the cases.

Fourth. Continuation of cases more than two weeks after most of the flies had been killed by cold weather.

Fifth. The sudden cessation of cases 12 days after the institution of hypochlorite treatment.

GENERAL CHARACTER OF THE EPIDEMIC.

The doctors of Fort Dodge state that during August of this year an extensive epidemic of diarrhea prevailed. The cases were severe but of short duration, usually not over two or three days.

The cases of typhoid which I saw were of rather more than average severity, but a number of cases were reported to have recovered within three weeks. The occurrence of 100 cases in 10 months in a population of 15,000 is equivalent to a case rate per annum of 800 per 100,000.

The case fatality rate was low-about 4 per cent but several cases contracted in Fort Dodge went elsewhere for treatment, and at least one of these is known to have resulted fatally

The occurrence of 11 cases, probably by contact, indicates that the physicians' orders regarding bedside precautions against infection were not carefully carried out, and the importance of reiterating instructions to persons nursing typhoid cases was urged upon them. Some of the physicians were using protective inoculations, and were advised to continue and extend these inoculations as far as possible. It having been decided that the water was responsible for this outbreak, the question arises as to why the disease should have been so much more prevalent in the southern than in the northern side of town. The possibility of some physical or mechanical reason why a greater percentage of river water should have reached the pipes in the southern part of town was considered and carefully gone over by Mr. Alden and myself. This included a careful inspection of the pump house and the method of mixing the water from the various sources prior to its entry into the mains. Previous examinations of the water had shown a higher degree of contamination in the Oleson Park tap and drinking fountain than at the intake.

The entire water system has an unusually large number of dead ends. These are really more numerous in the northern than in the southern section, but on the other hand, feeling that the natural circulation in the southern section was better than in the northern, there was more frequent flushing of the pipes in the northern section. Citizens

reported that certain mains in the southern section-and the mains particularly referred to are those supplying the districts where the fever was most prevalent-had not been flushed in 15 and 24 months, respectively. The water superintendent denies so long an interval, but admits that these pipes were flushed less frequently than in the northern part of town.

There is an added reason for the probable slower movement in these pipes in the fact that the mains in this section were laid with a view to supplying certain gypsum mills, and are therefore much larger than is necessary, since the expectation of supplying the mills was not realized.

The pressure tank referred to is emptied and cleaned only twice annually. Owing to the greater use of water in the southern part of town more of the flow from this tank, when the pumps are stopped, would flow to the southern section than to the northern section of town.

RECOMMENDATIONS SUBMITTED TO THE MAYOR AND COUNCIL.

(1) Secure a supply of pure water immediately. This may be accomplished by one of two methods:

(a) The plan at present in contemplation and in course of accomplishment, that is to say, the completion of the 2,000,000-gallon reservoir on Park Island, and the piping off of well No. 1 so as to exclude the water from the shaft, as no sewage contamination has ever been found in any one of the three artesian wells. This method, which will conserve the entire flow, will quickly give a safe supply of a sufficient quantity of water for present needs.

The growth of the town, however, and the extension of the water mains to portions of the town not at present supplied will soon require more water than the present wells will supply. Further, the artesian water has a high degree of permanent hardness, and is not a good water for commercial and industrial purposes.

Therefore, the second plan may of necessity come up for consideration in the near future.

(b) An entirely new plant located well above the town and local sources of pollution, the water to be taken from the Des Moines River and settling basins and filter beds provided. This plan would require the services of a sanitary engineer. In the meantime, and pending the completion of the reservoir, and so long as the water from the shaft is used, it is recommended (1) that the hypochlorite treatment be continued.

(2) It is recommended that all householders be required to connect with the city water and sewer systems where these are available, and that the water and sewer systems be extended as rapidly as funds are available for the purpose.

(3) Condemn and discontinue all surface wells and privies in such localities.

(4) Substitute sanitary closets for privies where sewers are not available.

(5) More frequent flushing of mains and terminal taps and more frequent cleansing of pressure tank.

(6) Connect all dead ends.

(7) Rigidly enforce city ordinances and State laws relating to the disposal of garbage and stable manure.

(8) Discontinue the use of the public slaughterhouse on Soldier Creek.

(9) Prohibit harvesting of ice below sewer outfalls. While this ice may be used only for cooling, this includes the freezing of ice cream, and it is a practical impossibility to avoid contaminating the ice cream with the melting ice.

(10) Establish a modern health department, paying the health officer sufficient compensation to enable him to give his entire time to the duties of the department.

CONCLUDING REMARKS.

During my stay at Fort Dodge I spoke by request before the local medical association on the Public Health Service, Its History and Functions, and on the Method of Conducting an Epidemiological Investigation.

I also spoke before a meeting of the mayor and council-to which citizens were invited-on the Causes of the Outbreak, and the Remedies Proposed.

Upon invitation of the president, I addressed the woman's club of Fort Dodge, the mayor and council and a number of citizens also being present.

Acknowledgment is made of many courtesies and valuable assistance rendered by the health officer, Dr. C. H. Mulroney.

Mayor Ford and Water Superintendent Pray showed many courtesies; and they and the physicians of Fort Dodge rendered every possible assistance.

It should be mentioned that on or about November 1 the hypochlorite plant was shut down for 24 hours for repairs, and because the stock of hypochlorite had become exhausted. It would not be surprising, therefore, if additional cases should develop about November 12 to 15.