(1) From unfiltered river supply to filtered river supply (2) From unfiltered river supply to wells (3) From polluted river supply to conserved river supply It may be urged that improved methods of medical treatment are responsible for a considerable reduction in the death rates from typhoid fever, but when we see such a striking change immediately after the installation of filtration plants as in the case of the American cities shown in the accompanying diagram, we are forced to the conclusion that water purification plays the most important rôle. The rates in this chart are per 100,000 of population, except in the case of the city of Cincinnati where a comparison is made in the number of deaths since the introduction of filtered water, for November and December, 1907, January, February, and March, 1908, and the corresponding months for 1905, 1906, and 1907. For details see weekly reports of the Board of Health of Cincinnati, March 20, 1908. ABRUPT REDUCTION IN DEATH RATES FROM TYPHOID FEVER INCIDENT TO WATER PURIFICATION IN FIVE AMERICAN CITIES. The next table with the diagram on page 252 brings out the general movement of typhoid fever in different countries and cities showing percentage of decrease from first to last period shown. The period covered by Dr Wilbur is (as nearly as convenient) the last quarter of a century, and the rates are usually given for successive five-year periods, beginning with 1881. The table shows that during the last 25 years the death rate from typhoid fever has fallen in those 14 countries and cities from an average of 42.3 to 18.1 per 100,000, a reduction of 54.3%. A more striking reduction could have been shown, if statistics going back as far as 1870 had been included. The typhoid rate in Berlin in 1872, at a time when that city was riddled with cesspools and supplied with polluted water, was as high as 142 per 100,000. On account of the incomplete mortality returns everywhere prior to 1881, we have deemed it best to exclude all older foreign statistics, and for similar reasons Dr Wilbur begins his statistics for the United States with 1890. We have likewise excluded Mr Whipple's statistics, which tend to show that the death rate from typhoid fever in 12 States, including all of the New England States, New York, New Jersey, Maryland, California, Minnesota and Michigan, has fallen from 55 in 1880 to 21 per 100,000 in 1905. Table showing general movement of typhoid fever in different countries and cities, showing percentage of decrease from first to last period shown a Dr Wilbur obtained the foreign statistics from data compiled from the International figures given in the last report of the Registrar General of England and Wales, from which report the rates for London are also taken. The rates for the cities of Paris and Berlin are given in the Annuaire Statistique of the city of Paris for the year 1904, and the rate of Berlin for the period 1901-1905 was supplied by Dr Wilbur from data in his office. Dr Wilbur laments the fact that "it is even now difficult to obtain a satisfactory statement of the number of deaths from such an important disease as typhoid fever in certain foreign countries and the difficulty of securing comparative data increases as we go back. The disease was first accurately compiled by the Registrar General of England in 1869." 56254-09-19 The incomplete and unsatisfactory character of the mortality statistics in the United States is largely due to the limited extent of the registration area. The importance of vital statistics, which constitute the foundation stone of public hygiene, is not fully recognized by our States, and yet as remarked by Dr Billings "when we wish to study the healthfulness of a city, whether it is getting better or worse, or judge correctly the effect of certain sanitary laws, we should not only know the number of deaths, but also the amount and character of the prevalent diseases, together with accurate information as to the number of population at different ages." OTHER WATER-BORNE DISEASES What has been said of typhoid fever is equally true of other waterborne diseases like cholera, dysentery, cholera morbus, diarrheal diseases and the transmission of the eggs of intestinal and other parasites, because the germs or eggs of these diseases are present in the intestinal tract and presumably also in sewage contaminated water. Thus, for example, the cholera epidemic of Hamburg in August, 1892, resulting in 17,020 cases, with 8,605 deaths, was caused by a band of gypsies camped on the banks of the river Elbe, and the discharges of one of its members suffering from cholera were emptied into the river which at that time was served to the inhabitants of Hamburg without filtration. The epidemic spared the adjoining city of Altona, which derives its water from the same river after receiving the sewage of Hamburg with its 800,000 people, but Altona filtered its water and Hamburg at that time did not. EFFECTS OF PURE WATER ON GENERAL DEATH RATES We have already pointed out what the purification of Potomac water has accomplished in the way of reducing the mortality from typhoid, malarial and diarrhoeal diseases. Mr Allen Hazen," one of the most distinguished experts on water purification in America, has conclusively shown that as a result of the installation of filtration plants in five cities. supplied previously with an impure water, there was not only a reduction a See paper read at the International Engineers' Congress at St. Louis in 1904. Mr Hazen found in five cities where the water supply had been radically improved A reduction in total death rate with the introduction of a pure water supply____ Difference being decrease in death rate attributable to change in water Of this, the reduction in deaths from typhoid fever was.. Per 100,000. 440 137 303 71 Leaving deaths from other causes attributable to change in water supply. 232 |