The Topic of This Month Vol.27 No.5(No.315)

HIV/AIDS in Japan, 2005

(IASR 27: 115-116; May, 2006)

HIV/AIDS surveillance was initiated in 1984 and conducted in compliance with the AIDS Prevention Law during 1989-March 1999. From April 1999, it has been implemented as part of the National Epidemiological Surveillance of Infectious Diseases (NESID), in accordance with the Law Concerning the Prevention of Infectious Diseases and Medical Care for Patients of Infections (the Infectious Diseases Control Law). Since the amendment of the Law in November 2003, HIV/AIDS has been classified as a category V notifiable infectious disease (for reporting guidelines, refer to The numbers of HIV-infected cases (persons who have not developed AIDS) and AIDS patients reported in this article are based on figures from the 2005 annual report of the National AIDS Surveillance Committee (ascertained on February 27, 2006) which has been released by the Specific Disease Control Division (SDCD), the Ministry of Health, Labour and Welfare (MHLW) (

1. Trend in HIV/AIDS cases during 1985-2005: In 2005, 832 new HIV cases (769 males, 63 females) and 367 new AIDS patients (340 males, 27 females) were reported. The former outnumbered that in 2004 (780) and is the largest number ever reported, and the latter was fewer than the figure of 2004 (385) (Fig. 1). Japanese males accounted for 85% of all HIV cases (82% in both 2003 and 2004) and for 79% of all AIDS patients (75% in both 2003 and 2004).

During 1985-December 31, 2005, 7,392 HIV cases (5,661 males, 1,731 females) and 3,644 AIDS patients (3,171 males, 473 females) were reported (excluding those infected through coagulation factor products), corresponding to 5.789 HIV cases and 2.854 AIDS patients per 100,000 population, respectively. In addition, 1,435 HIV cases infected through coagulation factor products (including 167 living and 579 deceased AIDS patients) were reported by an independent national survey (as of May 31, 2004).

In 2005, AIDS deaths by voluntary case-follow-up reporting (alive¨death) to SDCD, MHLW, totaled 5 (4 Japanese male and 1 non-Japanese male cases).

Nationality and gender: Among HIV cases, the number of Japanese males continues to increase (Fig. 2), with further rise to 709 cases in 2005 (636 in 2004). In contrast, the number of Japanese females decreased (44¨32) and those of non-Japanese males and females slightly decreased (Fig. 2). Of AIDS patients, the number of Japanese males reported in 2005 was 291, the same level as that reported in 2004 (290).

Modes of infection and age distribution: In 2005, record-highs of 514 HIV cases (449 in 2004) and 129 AIDS patients (126 in 2004) due to homosexual contact (including bisexual contact) were reported among Japanese males (Fig. 3). The numbers of Japanese HIV male cases infected through homosexual contact accounted for 80% of 15-24 years (Fig. 4-a), 76% of 25-34 years (Fig. 4-b), and 68% of 35-49 years (Fig. 4-c), and increased in every age group category, significantly in the 25-34 year group. In male HIV cases greater than or equal to 50 years of age, the proportion of cases infected via heterosexual contact was higher than in other age groups (Fig. 4-d). Most HIV cases among Japanese females were between 25-34 years of age, and occurred through heterosexual contact. Infections due to intravenous drug abuse or mother-to-child infection accounted for less than 1% of all HIV cases and AIDS patients; figures are lower than those in other countries. In 2005, 10 cases of infection due to intravenous drug abuse (3 HIV cases, 7 AIDS patients) and 1 case due to mother-to-child infection (1 HIV case, 0 AIDS patient) were reported.

Estimated regions of acquiring infection: In 2005, most of the HIV cases and AIDS patients were presumed to have acquired infection in Japan (83% of HIV cases, 69% of AIDS patients). After 2001, of non-Japanese male cases, more people were infected in Japan.

Regions of reporting: In each of the following 15 prefectures, physicians diagnosed and reported greater than or equal to 10 HIV cases in 2005 (in 13 prefectures in 2004); in the decreasing order Tokyo, Osaka, Aichi, Kanagawa, Shizuoka, Saitama, Chiba, Fukuoka, Hyogo, Hokkaido, Okinawa, Hiroshima, Ibaraki, Tochigi and Mie. HIV cases increased in 6 districts other than Kanto-Koshin-etsu in 2005, showing a locally spreading tendency, as was the case in 2004.

2. HIV-antibody-positive rates among blood donors: HIV-antibody-positive rates of blood donors were steadily increasing every year until 2004. In 2005, 78 positive individuals were identified among 5,320,602 blood donations (75 males, 3 females), corresponding to 1.466 positives per 100,000 donations (2.279 for males, 0.148 for females), which is lower than 1.681 in 2004 (Fig. 5). Nevertheless, the tendency was the same that the ratio, HIV-antibody-positive rate among blood donors divided by HIV infection rate per population, was very high as compared with that in Western countries (see IASR 21:140-141, 2000).

3. HIV antibody tests and counseling at health centers: In 2005, 100,278 HIV tests were conducted at health centers and other settings provided by municipalities; this figure increased from 89,004 in 2004 and exceeded 100,000 after 12 years from 1993 (Fig. 6). The positive results in 2005 count at 331 (0.33%); of 80,899 tests conducted at health centers, 181 positives (0.22%) were found, while a noticeably higher rate of positives in tests conducted outside of health centers, 150 positives of 19,388 tests (0.77%), were found (see p. 118 of this issue). The number of counseling sessions also increased from 146,585 in 2004¨161,474 in 2005, the second largest next to that in 1996 (172,641), in the past 10 years.

Conclusions: Numbers of HIV and AIDS cases in 2005 were the largest ever recorded, surpassing 1,000 taking over from 2004. Moreover, the cumulative numbers of reported cases were more than twice those at the end of 1999, 6 years ago (3,466 HIV cases, 1,587 AIDS patients). The period for doubling is becoming shorter (the cumulative reported number as of the end of 2004 was twice that 7 years ago). In 2005, as was the case in 2004, the increase in infection by homosexual contact among males is conspicuous. For future countermeasures, active prevention for HIV infection among young people, centering the infection through male homo-sexual contacts are necessary (see p. 117 of this issue).

Until now, preventive measures have been implemented in many aspects, but not able to stop the increasing tendency. On April 1, 2006, the revision of HIV/AIDS guidelines was released. In compliance with new guidelines, the government and municipalities are proposed to further encourage HIV testing and counseling/consultation programs with consideration for accessibility in each district, to clearly define the target population in line with the regional situation for disseminating knowledge of HIV/AIDS and promoting prevention behaviors, and to make efforts in developing early diagnosis, treatment and control of spread of HIV infection.

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