CHOLERA, PLAGUE, SMALLPOX, TYPHUS FEVER, AND YELLOW FEVER Continued.

Reports Received from June 30 to October 19, 1923-Continued.

PUBLIC HEALTH REPORTS

VOL. 38

NOVEMBER 2, 1923

No. 44

PREVALENCE OF POLIOMYELITIS.

The late summer and fall of 1923 have brought a somewhat larger seasonal increase in the prevalence of poliomyelitis in the United States than occurred in either 1920 or 1922, although a smaller number of cases has been reported than that recorded for 1921. The greatest number of cases has been reported from New York, Massachusetts, New Jersey, Kansas, California, and Illinois. The following tables give the number of cases reported to the United States Public Health Service by the State health officers:

Cases of poliomyelitis reported to the United States Public Health Service, by weeks, July 29-October 27, 1923.

Comparison of the years 1920–1923.

Number of cases of poliomyelitis reported by State health officers, by
weeks, July 29-Oct. 27, 1923, and corresponding weeks of 1920, 1921,
and 1922.

Early in October the disease was reported to be more prevalent in California than at any time since 1912, with the exception of 1921. In 1912 there were reported in that State 531 cases with 129 deaths, and in 1921 a total of 282 cases was reported.

The Weekly Bulletin of the California State Board of Health for October 13, 1923, called attention to the situation. It stated that the disease was more prevalent in the southern part of the State, although sporadic cases had occurred in other sections. At the meeting of the State board of health on October 6, 1923, the quarantine period for poliomyelitis was placed at three weeks, and it was provided that all contacts must be isolated for a period of two weeks.

The following information regarding the occurrence of the disease in New York City is taken from the Bulletin of the city depart ment of health for October 20, 1923:

Poliomyelitis in New York City-Comparison by months.

It is stated that, clinically, the great majority of the cases have been mild, as also the sequellæ. During the first four months of the year the case fatality rate was approximately 30 per cent, whereas during May and June it dropped to 16 per cent. The table shows that for the first nine months of 1921 the case fatality rate was 23, whereas for the corresponding period of 1923 it was 9.1.

It was stated that the occurrence of two cases in one family has been extremely rare. Drastic measures with respect to hospitalization were not employed. Patients were permitted to remain in their homes, being kept under quarantine for a period of three weeks. School children were excluded from school and food handlers were not permitted to work for a period of two weeks following last contact with a case of poliomyelitis.

THE NOTIFIABLE DISEASES.

PREVALENCE DURING 1922 IN STATES.

The tables which appear on the following pages have been compiled from data furnished by the health officers of the several States, the District of Columbia, and insular possessions. The data for syphilis and gonorrhea were furnished by the Division of Venereal Diseases of the Public Health Service.

The following is a list of the diseases included:

The following table shows the States (including the District of Columbia and insular possessions) for which morbidity and mortality

As the prevalence of disease for the Provinces in the Philippine Islands was reported by quarters, the data for the Provinces and Manila are given in separate tables.

For the purpose of comparison with States, the data for New York City are given in a separate table.

The populations given in the tables and used in computing case and death rates were estimated as of July 1, 1922, unless otherwise indicated.

For most of the diseases four tables are given: (1) Medians, (2) morbidity, (3) mortality, (4) rates.

It is believed that the median gives a better idea of the usual conditions than does the arithmetical average, which has been used in some former publications.

In ascertaining the medians,' data for the years 1913 to 1921, inclusive, were used, but for many States information was not available for each of the nine years. The column headed "Number of years included" shows the number of years for which data were obtained.

In comparing the figures for 1922 with the medians for preceding years, it should be borne in mind that an increase in the number of cases reported may indicate that there were more cases of the particular disease in the State during 1922, or it may indicate that the cases were better reported by the physicians.

A relatively large number of reported cases of a communicable disease, as indicated by a high case rate (and more especially when accompanied by a relatively small number of deaths, as indicated by a low fatality rate), usually means that the health department of that State is active and that the cases of the disease are being well reported by the practicing physicians. It does not necessarily mean that the disease is more prevalent in that State than in other States. A high fatality rate may mean that the disease was unusually virulent in a State, that the physicians did not treat the disease in that State with the success usual elsewhere, or that the practicing physicians did not report all of their cases. On the other hand, an unusually low fatality rate may be due to the fact that the disease in the State was unusually mild, that the physicians treated it with unusual success, that the practicing physicians reported their cases satisfactorily, or that the registration of deaths was incomplete, or the assignment of the causes of death inaccurate.

In some instances comparatively large numbers of cases of diseases reported in certain States may be due to the system of reporting rather

1 The median has been defined as the magnitude of the middle item in an array. If the numbers of cases reported are arranged so that the greatest number reported in any one year is first, the second greatest number is second, and so on, then the number of cases in the center of the array is the median. The following illustration shows the method followed when data for five years are available: In a State reporting 60 cases in 1915, 79 cases in 1916, 71 cases in 1917, 58 cases in 1918, and 53 cases in 1919, the median is 60 cases.