Background: In the United States, an increasing proportion of women infected with the human immunodeficiency virus (HIV) live in nonmetropolitan areas. Little is known, however, about the risk factors for HIV transmission in women outside large cities.
Methods: We interviewed and tested 1082 (99.8 percent) of 1084 consecutive pregnant women who registered for prenatal care at a public health clinic in western Palm Beach County, Florida. This rural agricultural area of about 36,000 people is known to have a high prevalence of HIV infection.
Results: The seroprevalence of HIV was 5.1 percent (52 of 1011 women). Black women who were neither Haitian nor Hispanic had the highest rate of infection (8.3 percent [48 of 575]). Only 4 of 1009 women (0.4 percent) reported ever injecting drugs, and the 4 were HIV-seronegative; however, 14 of 43 users of "crack" cocaine (33 percent) had HIV infection. At prenatal registration, 131 of 983 women (13 percent) tested positive for gonorrhea, chlamydial infection, or syphilis. By multivariate logistic-regression analysis, HIV infection was found to be independently associated with having used crack cocaine (odds ratio, 3.3; P < 0.001), having had more than two sexual partners (odds ratio, 4.6; P < 0.001), being black but neither Hispanic nor Haitian (odds ratio, 11; P < 0.001), having had sexual intercourse with a high-risk partner (odds ratio, 5.6; P < 0.001), and testing positive for syphilis (odds ratio, 3.1; P = 0.015). Nevertheless, 11 of the 52 HIV-infected women (21 percent) reported a total of only two to five sexual partners and no known high-risk partners, had never used crack cocaine, and had no positive tests for sexually transmitted disease.
Conclusions: In the rural community we studied, most of the women with HIV infection acquired it through heterosexual contact. The increasing seroprevalence of HIV and the increasing incidence of syphilis and use of crack cocaine mean that other women may be at similar risk of acquiring heterosexually transmitted HIV infection.