1. Trend in HIV/AIDS cases during 1985-2006
The number of new HIV cases reported in 2006 was 952 (863 males and 89 females), which exceeded the figure in 2005 (832), being the largest in the past. The number of AIDS patients was 406 (368 males and 38 females), the largest in the past (the largest number before 2005 was 385 in 2004) (Fig. 1). Japanese males accounted for 83% of all HIV cases (82% in 2004 and 85% in 2005) and for 83% of all AIDS patients (75% in 2004 and 79% in 2005).
During 1985-December 31, 2006, 8,344 HIV cases (6,524 males and 1,820 females) and 4,050 AIDS patients (3,539 males and 511 females) were reported (excluding those infected through coagulation factor products), corresponding to 6.531 HIV cases and 3.170 AIDS patients per 100,000 population, respectively. In addition, 1,438 HIV cases infected through coagulation factor products (including 168 living and 606 deceased AIDS patients) were reported by an independent national survey (as of May 31, 2006).
During 2006, AIDS deaths by voluntary case-follow-up reporting (alive¨death) to SDCD, MHLW, totaled 22 (19 Japanese males, 3 Japanese females and 0 non-Japanese case).
Nationality and gender: Among HIV cases, Japanese males continued to increase (Fig. 2-a), with a significant rise to 787 cases in 2006 (709 in 2005). Japanese females also increased (32¨49), and non-Japanese males and females also increased slightly (Fig. 2-a). Among AIDS patients, Japanese males increased to 335 in 2006 (291 in 2005) and Japanese females to 20 (11 in 2005) (Fig. 2-b).
Mode of infection and age distribution: In 2006, record-highs of 571 HIV cases (514 in 2005) and 156 AIDS patients (129 in 2005) due to homosexual contact (including bisexual contact) were reported among Japanese males (Fig. 3). The numbers of Japanese male HIV cases infected through homosexual contact accounted for 80% of 15-24 years (Fig. 4-a), 77% of 25-34 years (Fig. 4-b), 64% of 35-49 years (Fig. 4-c) and 38% of 50 years or older (Fig. 4-d)D In male HIV cases older than or equal to 50 years of age, the proportion of cases infected via heterosexual contact has been higher than that in other age groups (Fig. 4-d). Of these age groups, HIV cases due to homosexual contact outnumbered those due to heterosexual contact as well as of younger generations. In Japanese females, most HIV cases and AIDS patients were due to heterosexual contract, and most of HIV cases were 25-39 years old (Fig. 4-b, c). 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 2006, 7 cases of infection due to intravenous drug abuse (4 HIV cases and 3 AIDS patients) and 1 case due to mother-to-child infection (1 HIV case and 0 AIDS patient) were reported.
Regions of acquiring infection/ of reporting: In 2006, most of the HIV cases and AIDS patients were presumed to have acquired infection in Japan (87% of HIV cases and 78% of AIDS patients). After 2001, of non-Japanese male cases, more people were infected in Japan. In each of the following 16 prefectures, physicians diagnosed and reported more than or equal to 10 HIV cases in 2006 (in 15 prefectures in 2005); in the decreasing order Tokyo, Osaka, Aichi, Kanagawa, Chiba, Shizuoka, Tochigi, Hyogo, Fukuoka, Kyoto, Hokkaido, Ibaraki, Saitama, Nagano, Miyagi and Okinawa. HIV cases increased in 2006 in Hokkaido/Tohoku, Kanto/Koshin-etsu (excluding Tokyo), Tokyo, Tokai and Kinki districts and AIDS patients in Hokkaido/Tohoku, Tokyo, Tokai, Kinki and Kyushu districts.
2. HIV-antibody-positive rates among blood donors
In 2006, 87 positive individuals were identified among 4,987,857 blood donations (82 males and 5 females), corresponding to 1.744 positives per 100,000 donations (2.572 for males and 0.278 for females), which is greater than 1.681 in 2004 (Fig. 5) and the largest ever. The HIV antibody-positive rate among blood donors divided by HIV infection rate per population, was still very high as compared with that in Western countries (see IASR 21:140-141, 2000).
3. HIV antibody testing and consultation/ counseling at health centers
In 2006, 116,550 HIV tests were conducted at health centers and other settings provided by municipalities; this figure increased from 100,287 in 2005 (Fig. 6). The positive results in 2006 counted at 440 (0.38%); of 93,497 tests conducted at health centers, 248 positives (0.265%) were found, while a noticeably higher rate of positives in tests conducted outside of health centers, 192 positives of 23,063 tests (0.883%), were found. The number of counseling sessions also increased from 161,474 in 2005 to 173,651 in 2006 (Fig. 6)
Conclusion: The reports of HIV/AIDS in 2006 renewed the past largest number. Particularly, the increase rate of HIV cases was large and spread of HIV infection was not stopped. Increase in male cases due to homosexual contact was conspicuous and by age groups, 20s-30s have a majority as before, a large increase was seen in groups of 30s-40s in 2006.@Both HIV cases and AIDS patients are continuously increasing not only in Tokyo and Kanto districts but also in local large cities in Kinki and Tokai districts. For future countermeasures, active preventive measures are necessary against HIV infection among 20s-40s age groups and the infection due to homosexual contact among males.
HIV Testing Promotion Week in June started in 2006 in addition to World AIDS Day in December. Data showing the intensification of HIV testing system to provide more education with consideration for easy accessibility in 2006 is closely related to the increase in HIV testing and counseling (see p. 163 of this issue). In response to regional situation, government and municipalities are proposed to make efforts in clearly defining the target population and developing early diagnosis, treatment and control of spread of HIV infection under cooperation with people engaged in education and medical care, companies and nongovernmental organizations.