The odds of HIV transmission through a man and a woman refers to the way in which HIV is transmitted sexually. Through sexual transmission, if one partner is HIV-positive and the other partner is not HIV-positive, and engages in a single unprotected sexual act, there is a corresponding estimated probability of being infected with HIV, which is 0.1%. However, this is not an absolute probability, and the probability rises with the duration of the sexual act, as well as with broken wounds or broken mucous membranes. Or if one engages in transrectal sex, the same probability rises significantly. The probability of transmission from male to female is probably higher than that from female to male, because the level of HIV in male semen is higher, whereas the level of HIV in female vaginal secretions is slightly lower. However, the data say that there is no statistically significant difference between the two in areas with a high prevalence of AIDS.