Travel, heterosexual intercourse and HIV-1 infection.

One hundred and seventy AIDS cases and 547 HIV-1 antibody positive reports of infection in persons who are presumed to have become infected by sexual intercourse between men and women abroad are reviewed. Eighty three percent of people with AIDS and 99% of HIV-1 infected persons were reported to have been exposed in countries where heterosexual spread of HIV infection is well documented (i.e. WHO patterns II or I/II - see below). African countries were commonly cited. The group that had been exposed heterosexually in pattern II or I/II countries was young, and males slightly outnumbered females. Persons who are presumed to have become infected with HIV-1 through heterosexual contact abroad make up a heterogeneous group of travellers which includes holiday makers, business persons, students, refugees and immigrants. Research is needed to identify travellers whose high risk behaviour makes them vulnerable to HIV-1 infection, and to develop effective health education measures for them.