HIV/AIDS surveillance system and reported cases of human immunodeficiency virus infection and acquired immunodeficiency syndrome in Japan (1983-1993).

The Ministry of Health and Welfare forms the AIDS Surveillance Committee, which publishes HIV infection at two-month intervals. As at December 1993, the Ministry of Health and Welfare reported 267 AIDS cases and 1,143 HIV infection cases. Epidemiological data in Japan showed a rapid increase of cases of transmission through heterosexual contact since 1991, before which cases of transmission due to homosexual contact were relatively large in number according to reports. Sporadic cases of mother-to-child transmission and some cases due to injection of drug use were also reported. However, others/unknown cases were 449 (31.8%). Although the reported number of AIDS cases and HIV infection cases in Japan is still small, a rapidly increasing HIV epidemic is feared. It is predicted that the primary mode of transmission will be heterosexual contact and that another epidemiological characteristics will be diversified modes of transmission. Therefore, the present surveillance should continue and actively track the epidemic and provide useful information for planning prevention strategies in Japan.