Geo-Demography of HIV/AIDS in Japan from 1985 to 2011: Incidence and Transmission Mode under Influence of Population Size/Density

Abstract

A stable relation was found between number of HIV/AIDS patients (P) and population size (N) and between HIV/AIDS incidence (I) and population density (D). The relation could be expressed as P = kN^m or I = hDⁿ, where k, h, m, and n are constants. For “AIDS”/“AIDS diagnosis”, the constant m was 1.5 for Japan and 1.3 for the United States of America (USA); n was 0.38 for both Japan and the USA. These observations indicated that larger population sizes related to disproportionately larger numbers of HIV/AIDS patients, and denser populations had disproportionately higher incidences of HIV/AIDS. Considering the wide geo-demographic difference between the two countries, it was striking that the same equations with constants within a narrow range were applicable to both Japan and the USA. Modes of HIV transmission appeared to be variable among prefectures in Japan. Homosexual transmission was suggested as being more predominant in more populated prefectures.