The Topic of This Month Vol.26 No.5(No.303)

HIV/AIDS in Japan, 2004

(IASR 2005; 26 : 113-114)

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 have been classified as category V notifiable infectious diseases (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 2004 annual report of the National AIDS Surveillance Committee (ascertained on April 25, 2005) which has been released by the Specific Disease Control Division (SDCD), the Ministry of Health, Labour and Welfare (MHLW) (

1. Trends in HIV/AIDS cases during 1985-2004: In 2004, 780 new HIV cases (698 males, 82 females) and 385 new AIDS patients (344 males, 41 females) were reported, both the largest ever and significantly exceeding figures in 2003 (Fig. 1). Japanese males accounted for 82% of all HIV cases (78% in 2002, 82% in 2003) and for 75% of all AIDS patients (75% in both 2002 and 2003).

During 1985-December 31, 2004, 6,560 HIV cases and 3,277 AIDS patients were reported (excluding those infected through coagulation factor products), corresponding to 5.140 HIV cases and 2.568 AIDS patients per 100,000 population, respectively. In addition, 1,434 HIV cases infected through coagulation factor products (including 167 living and 564 deceased AIDS patients) were reported by an independent national survey (as of May 31, 2003).

Nationality and gender: Among HIV cases, the number of Japanese males continues to increase (Fig. 2-a), with a significant rise to 636 cases in 2004 (525 in 2003). In contrast, the numbers of Japanese females and non-Japanese males and females have remained level over the past few years (Fig. 2-a). Among AIDS patients, the number of Japanese males continues to increase (Fig. 2-b), with 290 reported in 2004 (252 in 2003).

Modes of infection and age distribution: In 2004, record-highs of 449 HIV cases and 126 AIDS patients due to homosexual contact (including bisexual contact) were reported (Fig. 3). The numbers of Japanese HIV male cases infected through homosexual contact have been increasing in every age group category (15-24 years [Fig. 4-a], 25-34 years [Fig. 4-b], and 35-49 years [Fig. 4-c]), with a significant increase observed in the 25-34 year group. Although small increases have occurred in male HIV cases greater than or equal to 50 years of age over the past few years, the proportion of cases infected via heterosexual contact in this age group has been higher than in other age groups (Fig. 4-d). Most HIV cases among Japanese females are between 25-34 years of age, and have 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 that are lower than in other countries. In 2004, 5 cases of infection due to intravenous drug abuse (3 HIV cases, 2 AIDS patients) and 2 cases due to mother-to-child infection (1 HIV case, 1 AIDS patient) were reported.

Regions of acquiring infection/of reporting: In 2004, most of the HIV cases and AIDS patients were presumed to have acquired infection in Japan (82% of HIV cases, 70% of AIDS patients). HIV cases have been on the increase in all district, with more than 10 cases reported in each of the following 13 prefectures (listed in descending order of case counts): Tokyo, Osaka, Kanagawa, Aichi, Chiba, Kyoto, Shizuoka, Hyogo, Saitama, Nagano, Hiroshima, Okinawa, Ibaraki. Hiroshima and Okinawa Prefectures, which reported noticeable increases in HIV cases in 2003 despite low numbers of cases overall, experienced further increases in numbers of HIV cases in 2004.

2. Deaths due to AIDS: Up until March 31, 1999, there were 596 deaths due to AIDS, of which 485 were Japanese (445 males, 40 females) and 111 non-Japanese (77 males, 34 females). During April 1999-December 31, 2004, the number of fatal cases reported to SDCD, MHLW by case-follow-up data (alive¨death) totaled 195, consisting of 162 Japanese (151 males, 11 females) and 33 non-Japanese (21 males, 12 females). In 2004, there were 25 AIDS deaths, of which 23 were Japanese (21 males, 2 females) and two non-Japanese (1 male, 1 female). Because case-follow-up reporting is voluntary, the number of death reports may not necessarily be high. Therefore, these figures may represent considerable underestimates of actual numbers of fatalities.

3. HIV-antibody-positive rates among blood donors: HIV-antibody-positive rates of blood donors have been steadily increasing every year. In 2004, among 5,473,119 blood donations, 92 positive individuals were identified (88 males, 4 females), corresponding to 1.681 positives per 100,000 donations (2.629 for males, 0.188 for females) (Fig. 5). In view of these results, an increase in latent HIV cases in this country has been suggested. There is also the possibility that many people are donating blood as a means of getting tested for HIV. To prevent such blood donations, it will be necessary to strengthen measures described in section 4 that will allow easier access to testing.

4. HIV antibody testing and consultation/counseling at health centers: In 2003, 75,539 HIV tests were conducted at health centers operated by municipalities; this figure increased to 89,004 in 2004. The number of consultation/counseling sessions also increased from 130,153 in 2003 to 146,585 in 2004. In Kawasaki City, the number of test subjects and positive detection rate both increased after free, drop-in anonymous testing services on Sundays were established (see p. 115 of this issue). According to an investigation conducted on October 20, 2004 by SDCD, MHLW, targeting health centers that introduced rapid HIV testing and late night/holiday testing after 2002, the monthly average number of examinees increased a maximum of about 9-fold in health centers introducing rapid, same-day results testing and approximately 5-fold in those introducing testing at night. On October 29, 2004, a notice by the Head of SDCD, MHLW, titled "Promoting the introduction of rapid methods of HIV antibody testing" was issued. With HIV cases on the increase in every district, it is necessary to further encourage and promote HIV testing and counseling programs, centering on health centers, and to work toward early diagnosis, treatment, and control of spread of HIV infection.

Conclusion: Numbers of HIV and AIDS cases in 2004 were the largest ever recorded, surpassing 1,000 combined and representing a persistent, increasing trend. Moreover, the cumulative number of reported cases as of the first quarter of 2005 has now exceeded 10,000 (see p. 125 of this issue). HIV cases and HIV antibody positive rates among blood donors have doubled over the past 7 years. Although various prevention measures have been developed, these increasing trends show no sign of touching bottom. HIV/AIDS guidelines released in October 1999 are reviewed and revised once every five years, and at present, are being prepared for submission to the Section of Infectious Diseases, Health Sciences Council.

The increase in infections among males via homosexual contact between 2003 and 2004 was conspicuous. Upward trends in both young male and female Japanese HIV cases continue, calling for further attention toward this age group. Social education to help disseminate knowledge of HIV/AIDS and promote prevention behaviors will become more critical, and increased efforts by public health and education officials will be expected.

Reports of AIDS patients: These are reports of HIV cases with AIDS-defining disease already developed at diagnosis. They might not notice their HIV infection before development of AIDS.

Reports of HIV-infected: These are reports of those whose infection became clear by a chance (blood test, consultation of a hospital, or blood donation) after infection with HIV and before developing AIDS-defining disease, being 10 years on the average (see IASR Vol. 23, No. 5). Once reported as HIV-infected, they may not be reported as AIDS patients even developing AIDS-defining disease later (in this case, reported voluntarily as separate case-follow-up data for HIV¨AIDS). The number of HIV/AIDS reports, therefore, reflect the infection status during the past 10 years and the opportunity to receive HIV testing or medical consultation, not indicating the real-time infection status.

Case-follow-up data for alive¨death: If reported as AIDS patient and die later, the physician will report voluntarily the case-follow-up data.

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