著者
竹内 昌平 山内 武紀 黒田 嘉紀
出版者
日本民族衛生学会
雑誌
民族衛生 (ISSN:03689395)
巻号頁・発行日
vol.80, no.1, pp.17-22, 2014 (Released:2014-03-28)
参考文献数
16
被引用文献数
1

The spread of influenza depends on contact among people. Contact rates are known to vary depending on the combination of age groups, which means that the age structure of a population affects the spread of influenza. We herein report how future changes in the population structure of Miyazaki Prefecture, a rural region in Japan, will affect the potential spread of influenza. We also report the results of an investigation on how future fertility changes will modify the potential spread through changes in the population structure. The basic reproduction number (R0) was used as an indicator of spread. The future population structure was projected by the cohort component method. Age-group-specific contact rates were obtained by a questionnaire survey. We found that the R0 of a new type of influenza will not change over the next 100 years if vital statistics remain constant (Scenario 0). If the total fertility rate increases by 10% or 25% from 1.7 (the level in 2011), the R0 in 2111 will be higher than that in Scenario 0. These results suggest that fertility recovery, an urgent demographic policy target in Japan, has the potential to increase the spread of influenza.
著者
竹内 昌平 黒田 嘉紀
出版者
一般社団法人日本衛生学会
雑誌
日本衛生学雑誌 (ISSN:00215082)
巻号頁・発行日
vol.65, no.1, pp.48-52, 2010 (Released:2010-02-05)
参考文献数
20
被引用文献数
6 8

Objectives: On April 24th, 2009, a new swine-origin influenza A (H1N1) was first reported in Mexico. Japan confirmed cases of the flu on May 9th, and the pandemic in Japan has become full-scale. The Ministry of Health, Labor and Welfare of Japan announced that the first peak of this pandemic was predicted to occur in October, 2009. Therefore, it is most important to predict the progress of this pandemic to be able to use medical resources effectively in Japan. Methods: We used a modified susceptible-exposed-infected-recovered (SEIR) model to calculate the number of infected people and hospital bed shortage during this pandemic. In this model, available medical resources were investigated on the basis of four vaccination scenarios. Results: Our model showed that it would take a further six months for the pandemic to peak than was predicted by the Ministry of Health, Labor and Welfare of Japan. Without vaccination, at the peak of the pandemic 23,689 out of 400,000 people would be infected and the hospital bed shortage would reach 7,349 in total. Conclusions: We suggest that mathematical models are strong tools to predict the spread of infectious diseases. According to our model, it is possible to prevent hospital bed shortage by vaccination.