流行性肝炎の疫学研究 第2報 赤磐地区における流行性肝炎の疫学観察（其の二）

Comparing the epidemic of infectious hepatitis that took place in Toyoda, Onoda, as well as Kumayama in Akaiwa County, during the period ranging from march 1951 to sept. do., with the previous report on the epidemic of malignant hepatitis submitted by february 1951, following results were obtained: 1. Number of patients, 120; total ever since the first. occurence, 213 cases; For the total populace, rate of occurence, Toyoda-39%, Onoda-3.1%, Kama-mura, 2.4%. 2. As for the type of disease. contrary to the previous occasion in which typical form was predominant, this time saw the predominaney of abortive form, of which the mortality rate proved only 0.83%, in comparison to 13.9% estimated in the former time. 3. As for state of starting estimated by month, as previous occasion, maximum occurrence took place in July and August. 4. As for age, showing similar trend as before, 21-30 occupying most cases, evenly has diffused from 10 to 60. There were actually 7 cases that were above 61, which verifies that contamination in old age is not so seldom. 5. As has been in the previous occasion, as to state of contamination, what may be called village infection occupied the majority of cases; where, a special increase of familiary infection has drawn our attention, amounting to the rate of 38.3%, in comparison to former 20.4%, Which, as the infection spread itself, increases in number. 6. Familiary infection may be explained by propagated epidemic form. Its three cases had been delivered. 7. On taking a bird's'-eye-view over the whole area that was infected, the special phase for this season will come under two heads; area in which new patients have emerged around those affected formerly., and the other, which has been contaminated with a fixed current toward areas not yet. infected. The latter is considered to take shift into the former form after a while. 8. Though rare, sporadic infection could be found in this epidemic too, each of which was a case infections being pressed onward into uncontaminated area, and 6 out of 9 cases have become the source for later infection. If theses poradic infections were considered in detail, these would be clear to have a connection with that of epidemic places and also able to come under propagated epidemic form.