[Start of PTB (Phthisis) mortality statistics in Japan (1)]

First "Statistics Annual", which included the population and vital statistics was published in Japan in 1882, and the numbers of death classified by major causes of death were tabulated by sex and age groups and by prefecture. Koch R reported the discovery of tubercle bacilli as the pathogen for TB in 1882, and since the latter half of 1883, the numbers of death due to PTB (Phthisis) were tabulated by prefecture, and by sex and age groups since 1884 annually except for 1885. Based on the population statistics and the numbers of PTB death, PTB (Phthisis) mortality was calculated by sex and age groups, and the results were shown in Table 1. PTB mortality per 100,000 increased from 78.2 in 1884 to 171.9 in 1899. Sex- and age-specific PTB mortality in 1884 showed a pattern increasing with age, and the PTB mortality of male was higher than that of female in adult as shown in Fig. 2. In 1889, low peak of mortality was seen in the age groups 15-19 and 20-29, and in these age groups, the PTB mortality was higher in female than in male. Such trend was seen more markedly in 1894 and 1899, while the rate was higher in male than in female in the age groups over 40. Trend of PTB mortality by sex and age groups was shown in Fig. 3. Rapid increase of PTB mortality in the age groups 10-14 and 20-29 could be explained by the rapid increase of young women workers in fast growing silk and spinning industries, but how rapid increase of PTB mortality in infants be explained? In "Statistics Annual", PTB (Phthisis) mortality rate by prefecture was printed, and the summarized table was shown in Table 2. The rates in 1883 and 1884 were calculated from the numbers of PTB death and the B-type population shown in the "Statistics Annual", which will be described in the next issue of this paper.