Prevalence and transmission of human immunodeficiency virus in Japan.

The routes of transmission of human immunodeficiency virus (HIV) can be divided into two categories, 1. sexual transmission (male-to-male, male-to-female and female-to-male) and 2. parenteral transmission by blood or blood products. Among 488 Japanese hemophiliacs, 165 (33.8%) were seropositive and were infected by the injection of factor VIII or factor IX manufactured from American sources. The rates of infection among hemophiliacs were 21.8% (19/87) and 36.8% (43/117), respectively for 1984 and 1985. Sera of 10,272 volunteer blood donors were all negative for anti-HIV. There have been 16 confirmed AIDS cases in Japan consisting of 8 male homosexuals and 8 hemophiliacs, so it can be concluded HIV infections have exclusively occurred among male homosexuals and hemophiliacs. But there are chances to transmit HIV by blood transfusion if the screening of whole blood units is not implemented in the near future.