PIP: Epidemiologic data from prostitute studies from around the world are reviewed to elucidate the importance of prostitutes as a link in the epidemic spread of HIV. Because prostitutes are viewed as a major source of a variety of sexually transmitted diseases (STDs), many researchers have studied their role in spreading the AIDS pandemic. In interpreting the review, 3 factors that influence the degree to which prostitutes spread STDs must be kept in mind: 1) the cultural differences that exist in the prevalence of prostitute use; 2) the inefficiency of female-to-male transmission of some diseases, such as HIV; and 3) the heterogeneousness of prostitutes as a group. Geographic areas demonstrate a range in the prevalence of infection, with the highest being in central African countries where sexual transmission is predominately heterosexual in contrast to countries with predominately homosexual transmission, as North and South America and Europe. Much of the HIV infection among prostitutes in Europe and North America is attributed to intravenous drug use; however, no studies report data on the risk of needle sharing versus sexual contacts with infected partners. The risk of infection increases with an increase in number of partners; however, the number of partners is less significant if partners come from areas with high infection rates. Susceptibility to HIV increases if there is concurrent infection by other STDs. The use of condoms reduces the risk of HIV transmission. Although contact with prostitutes is not currently listed as a recognized risk category for AIDS case surveillance, the contact may be a link in HIV epidemics in areas having lower prevalence of STDs that could act as cofactors for transmission or acquisition of HIV. Prostitutes must be taught to protect themselves and to teach their clients safer sex practices.