Investigation of the Proportion of Diagnosed People Living with HIV/AIDS among Foreign Residents in Japan

Abstract

Foreign residents represent an increasing proportion of newly diagnosed human immunodeficiency virus (HIV) infections and acquired immunodeficiency syndrome (AIDS) cases in Japan, though scant research has addressed this. This study aimed to estimate the diagnosed proportion of people living with HIV/AIDS (PLWHA) among foreign residents in Japan, covering 1990-2017 and stratifying by geographic region of the country of origin. A balance equation model was employed to statistically estimate the diagnosed proportion as a single parameter. This used published estimates of HIV incidence and prevalence, population size, visit duration, travel volume, as well as surveillance data on HIV/AIDS in Japan. The proportion varied widely by region: People from Western Europe, East Asia and the Pacific, Australia and New Zealand, and North America were underdiagnosed, while those from sub-Saharan Africa, South and South-East Asia, and Latin America were more frequently diagnosed. Overall, the diagnosed proportion of PLWHA among foreign residents in Japan has increased, but the latest estimate in 2017 was as low as 55.3%; lower than the estimate among Japanese on the order of 80% and far below the quoted goal of 90%. This finding indicates a critical need to investigate the underlying mechanisms, including disparate access to HIV testing.

Keywords: antiretroviral therapy; epidemiology; foreigner; importation; laboratory diagnosis; migration; mobile men with money; test-and-treat; travel; treatment as prevention.

Figure 1

Human immunodeficiency virus (HIV) and nationality in Japan and worldwide, 1990–2017. (A) Yearly incidence (i.e., the number of new infections) of HIV among foreign residents in Japan. (B) Cumulative number of HIV infections and acquired immunodeficiency syndrome (AIDS) cases among foreign residents in Japan. (C). Estimated yearly incidence of HIV infections in the home country, by region (as estimated by the Institute of Health Metrics and Evaluation). (D) Temporal distribution of the yearly number of foreign visitors to Japan, by region of the country of origin.

Figure 2

Estimated diagnosed proportion of human immunodeficiency virus (HIV) infections among foreign residents in Japan, 1990–2017. Estimates of the proportion of diagnosed infections out of the cumulative number of HIV infections and acquired immunodeficiency syndrome (AIDS) cases. Two panels are shown because of varying estimates. (A) People from Western Europe, Eastern Europe and Central Asia, East Asia and Pacific, Australia and New Zealand, and North America. (B) People from North Africa and Middle East, sub-Saharan Africa, South and South-East Asia, Caribbean, and Latin America.

Figure 3

Overall estimate of diagnosed proportion of human immunodeficiency virus (HIV) infections among foreign residents in Japan, 1990–2017. (A) Estimates of the diagnosed proportion of the yearly incidence of HIV infections. (B) Estimates of the diagnosed proportion of the cumulative number of HIV infections and acquired immunodeficiency syndrome (AIDS) cases in 1990–2017. In both (A,B), whiskers extend to the upper and lower 95% confidence intervals. Two horizontal lines show the estimated diagnosed proportions among Japanese national; 77–84% [19].

Figure 4

Comparison of observed and estimated HIV incidence and people living with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS; PLWHA) among foreign residents in Japan. (A) Bars represent the observed incidence of HIV diagnoses in Japan in 2017, by region of the country of origin. Solid squares represent the estimated number of HIV diagnoses when using our model. (B) Bars represent the observed cumulative number of HIV infections and AIDS cases in Japan from 1990–2017, by region of the country of origin. Solid circles show the estimated cumulative number of HIV infections and AIDS cases by region in Japan when using our model. Whiskers extend to the upper and lower 95% confidence intervals. It should be noted that a common logarithmic scale is used on the vertical axis.

Figure 5

Sensitivity of estimate of diagnosed proportion of the cumulative number of HIV infections and acquired immunodeficiency syndrome (AIDS) cases in 2017 to variations in ascertainment ratio. It should be noted that a common logarithmic scale is used on both horizontal and vertical axes. Further, it should be noted that the vertical axis is the fraction (i.e., the value 1 is equivalent to 100%).