The Topic of This Month Vol. 31, No. 8 (No. 366)

HIV/AIDS in Japan, 2009
(IASR 31: 226-227, August 2010)

HIV/AIDS surveillance in Japan started in 1984.  It was carried out in compliance with the AIDS Prevention Law from 1989 to March 1999, and, since April 1999, 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, which obliges notification of all the cases diagnosed by doctors (criteria of reporting is found in  The data presented below are derived from the final version (May 27, 2010) of the 2009 annual report of the National AIDS Surveillance Committee released by the Specific Disease Control Division, the Ministry of Health, Labour and Welfare (MHLW) (

1. Trend in HIV/AIDS cases reported during 1985-2009: Cases reported in 2009 were 1,021 for HIV (965 males and 56 females) and 431 for AIDS (407 males and 24 females).  The respective numbers for 2008 were 1,126 and 431 (Fig. 1).  In the AIDS surveillance, HIV is defined as the case that is detected by laboratory diagnosis before development of AIDS, and AIDS as the case detected by the manifest AIDS symptoms.

In addition, the independently conducted "nationwide survey of blood coagulation anomalies" has identified 1,439 HIV cases due to the contaminated coagulation factor products.  That number includes 171 AIDS patients alive and 648 cases deceased (as of May 31, 2009).

Total number of deceased cases reported to Specific Disease Control Division, MHLW, was nine (eight Japanese males and one non-Japanese female) in 2009. The number is considered far below the actual number, because the reporting is on voluntary basis.

Nationality and gender: Among 1,021 HIV and 431 AIDS cases, 88% (894/1,021) and 90% (386/431), respectively, were Japanese males.  The percentages remained similar in the past three years.  Among Japanese females, there were 38 HIV and 15 AIDS cases.  Among the non-Japanese, there were 71 HIV and 21 AIDS male and 18 HIV and 9 AIDS female cases (Fig. 2).

Infection route and age distribution: Among HIV and AIDS Japanese males, infection through homosexual (including bisexual) contact was the most frequent (Fig. 3).  In 2009, 74% of Japanese male HIV (659/894) and 53% of Japanese male AIDS (205/386) were infected through this route.  Those in their thirties and twenties dominated among Japanese male HIV cases (287 and 210, respectively) and those in their thirties and forties among Japanese male AIDS (97 and 48, respectively) (Fig. 4).

Majority of Japanese female HIV and AIDS cases were infected through heterosexual contact.  Drug abuse was implicated in total eight cases (HIV and AIDS altogether), six of Japanese nationality and two of non-Japanese nationality.  There were additional five cases that may have equal chance of infection through drug abuse and sexual contact.  Though mother-to-child infection was rare (see p.230 of this issue) and not reported from 2007 to 2009, two cases were reported in 2010 (as of June 2010).

Place of infection: For Japanese, in 2009, 90% of HIV (90% for male and 76% for female) and 80% of AIDS (80% for male and 67% for female) were presumably infected in Japan.  For non-Japanese males, infection in Japan has outnumbered infection outside of Japan since 2001; in 2009, 51% (36/71) were infected in Japan, 11 were infected outside of Japan, and 24 were unknown for place of infection.

Reports by districts: The top ten prefectures in 2009 were Tokyo (374), Osaka (171), Kanagawa (57), Aichi (54), Fukuoka (38), Chiba (34), Hyogo (31), Saitama (27), Hiroshima (24) and Hokkaido (23) (figures in parentheses are number of HIV cases reported).  In terms of per 100,000 population, they were Tokyo (2.91), Osaka (1.94), Okinawa (1.09), Hiroshima (0.84), Yamanashi (0.80), Fukuoka (0.75), Aichi (0.73), Kanagawa (0.64), Chiba (0.56) and Hyogo (0.55).

2. HIV-antibody-positive rates among blood donors: In 2009, there were 102 HIV-positives in 5,287,101 blood donations (96 males and 6 females), i.e., 1.929 positives (2.693 for males and 0.348 for females) per 100,000 donations (Fig. 5).  The corresponding figure in 2008 was 2.107.

3. HIV antibody tests and consultation provided by the local governments: The local governments are providing HIV antibody tests at health centers and at other facilities.  Total number of HIV tests carried out by the local governments in 2009 was 150,252 (Fig. 6); 0.29% of the tested (442/150,252) were HIV positive (0.28% in 2008).  The health centers covered 122,493 tests; 0.24% of the tested (289/122,493) were HIV positive.  Other facilities conducted 27,759 tests; 0.55% were HIV positive (153/27,759).  The positive rate in other facilities was about twice as high as in the health centers.  This difference is probably due to easier access to other facilities than to health centers.  The number of counseling provided by the local governments was 193,271 in 2009 in contrast to 230,091 in 2008.

4. HIV-2: It has been considered that, in contrast to HIV-1 that spreads widely in the world causing many deaths, HIV-2 is geographically limited and its infection remains asymptomatic in the lifetime.  However, since 2004, five HIV-2 cases have been reported and two of them were considered transmissions in Japan.  HIV-2 isolates from three cases were recombinants of group A and group B, and all the three cases had developed AIDS.  HIV surveillance should pay more attention to HIV-2 from now (see p. 232 of this issue).

5. Treatment of HIV/AIDS and drug-resistance: Owing to the recently developed anti-HIV drugs that has high genetic barrier in resistance acquisition, therapeutic failure due to antiretroviral resistance is becoming rare.  However, among patients who had been treated before development of such drugs, multi-drug resistance is a serious problem (see p. 233 of this issue).

Conclusion: The number of HIV reported in 2009 was lower than in 2008.  This reduction could have been due to the pandemic (H1N1) 2009 influenza, which may have diverted the local governmentsf activities more to the pandemic influenza response, and discouraged people from visiting sites of HIV counseling and/or testing.  Actually, number of HIV consultations and testing were 15-16% lower in 2009 than in 2008.  Therefore, it is quite possible that the reduction of HIV in 2009 was rather apparent than real.

In Japan, HIV transmission is progressing mainly among males in their thirties and twenties through homosexual contact (Fig. 4).  Similar situation is found in USA and in Europe.  UK and France respectively reported 7,370 and 4,068 new HIV infections in 2008 (, and USA estimates 56,300 new infections every year (  In all these countries, homosexual route of infection predominates.

In order to reduce chance of further transmission, early diagnosis is critical.  The local and national governments are requested to strengthen the public education on AIDS prevention and to promote HIV testing.  HIV testing and medical and other consultations that they provide should be accessible to socially active age groups (twenties, thirties and forties), because AIDS cases whose infection was detected only after development of AIDS increased particularly among males in their thirties and forties in 2009 (Fig. 4).  The local and national governments are advised to consider possible collaboration with appropriate partners, such as, educational and/or medical staff, private companies, and NGOs that are considered to be most suitable for intervention of the target populations (homosexuals, younger generations, sexual workers and their clients, males whose behaviors are conductive to HIV infection, etc) (see p. 228 & 229 of this issue).

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