About 25% of people living with HIV infection in the United States are women (Centers for Disease Control and Prevention [CDC], 2010). African American and Hispanic women represent 80% of all females diagnosed with HIV/AIDS in the U.S. (CDC, 2011). In 2008, compared with the prevalence of HIV infection among non-Hispanic white women (45 per 100,000), the prevalence among African American women (803 per 100,000) was almost 18 times as high, and among Hispanic women (248 per 100,000) 6 times as high (CDC, 2011).

Heterosexual sex is the primary mode of HIV acquisition among women (CDC, 2011). Risk factors for HIV infection among women of color include, but are not limited to, lower education and income, drug use, history of sexually transmitted infections (STIs), exchange sex, multiple sexual partners, inconsistent condom use, and violence victimization (Adimora et al., 2006; Amaro & Raj, 2000; Amaro, 1995; Javanbakht et al., 2010; Marin, Tschann, Gomez, & Gregorich, 1998; McNair & Prather, 2004; Moreno, El-Bassel, & Morrill, 2007; Nyamathi & Stein, 1997; Pulerwitz, Amaro, De, Gortmaker, & Rudd, 2002; Suarez & Siefert, 1998; Wingood & DiClemente, 1997; Wohl et al., 2002; Yeakley & Gant, 1997). Studies also suggest that aspects of women's sexual relationships and social/structural determinants (e.g., power dynamics, gender roles, financial decision making, communication patterns) may be important determinants of risk, both for engaging in behaviors and for doing so with partners that inadvertently place them at increased risk for HIV infection (Amaro & Raj, 2000; Krishnan et al., 2008; McNair et al., 2004; Sanders-Phillips, 2002; Suarez-Al-Adam, Raffaelli, & O'Leary, 2000; Zierler & Krieger, 1997). Furthermore, sexual contact networks, in particular how partner availability and choice may influence risk-taking behaviors, have important implications for HIV transmission (Adimora & Schoenbach, 2005; Doherty, Padian, Marlow, & Aral, 2005; Liljeros, Edling, & Nunes Amaral, 2003).

Most of the HIV epidemiologic and behavioral studies of women of color have focused on women who are at increased risk (e.g., drug users, sex workers, STI clinic attendees), pregnant women, HIV infected women, and adolescent females sampled in large urban settings with high HIV prevalence. Findings from those studies may not reflect the experiences or risks of heterosexually active women of color who do not meet high-risk inclusion criteria and who live in less urban or nonurban areas. In particular, there is limited understanding of sexual and drug-use behaviors, correlates of unsafe sex, and unrecognized HIV infection among women of color living in the southern U.S. despite increasing rates of new HIV diagnoses in this region (Fleming, Lansky, Lee, & Nakashima, 2006).

To address these issues, we conducted a cross-sectional epidemiologic study of heterosexually active African American women in rural counties of Alabama and North Carolina and Hispanic women in an urban county in southern Florida who had not previously been diagnosed with HIV infection. We tested participants for HIV to identify those who were infected and unaware of it. With data collected in a questionnaire, we characterized participants on a broad range of demographic, interpersonal, and behavioral factors and examined their associations with the sexual behavior that carries the highest risk for women acquiring HIV infection, namely, heterosexual anal intercourse (AI). Per act, unprotected anal intercourse (UAI) among women carries five times as great a risk as unprotected vaginal intercourse (UVI) for contracting HIV infection (Varghese, Maher, Peterman, Branson, & Steketee, 2002). It is also a strong risk factor for other STIs (Halperin, 1999) as well as abnormal anal cytology (Holly et al., 2001) and anal cancer (Frisch et al., 1997) in women.

A large percentage of women in our sample engaged in sexual behaviors that placed them at risk for HIV infection, and there some notable differences between the African American and Hispanic women. In the 12 months preceding enrollment, 87% engaged in UVI and 26% engaged in UAI (higher among Hispanic women than African American women). Among women who engaged in AI, 91% reported inconsistent condom use. UAI was more likely to occur with partners with whom women had a current or past relationship as opposed to casual partners. Nineteen percent of the women reported that they had been diagnosed with an STI in the past 12 months. The STI percentage was higher among the African American women. Also, a larger percentage of these women (compared with the Hispanic women) had a younger sexual debut, had more sex partners in the past 12 months, had ever experienced unwanted or forced sex, and had ever engaged in exchange sex. Some of these differences (e.g., more sex partners) may have occurred because a larger percentage of the African American women were single and younger than the Hispanic women. Social, cultural, and economic factors may have also contributed to these behavioral differences.

It is important to view our findings on AI in the context of other studies that have examined this behavior. In a 1997-2001 population-based study of risk factors for heterosexual HIV transmission in North Carolina, 18% of HIV-positive and 10% of HIV-negative African American women reported having had AI in the past 10 years (Adimora et al., 2006). The National Survey of Family Growth, a nationally representative survey among women 15-44 years of age conducted in 2002, found that 23% of Hispanic women, 22% of African American women, and 34% of white women had ever engaged in AI (Mosher, Chandra, & Jones, 2005).

In the 2009 National Survey of Sexual Health and Behavior, 21% of the 18-39 year old women in the sample (69% of whom were white) engaged in AI in the past 12 months (Herbenick et al., 2010). Other studies have focused on higher-risk populations. Among 18-25 year old women of color from a study conducted in 2006-08 in Hartford, CT and Philadelphia, PA in neighborhoods with high STI and teen pregnancy rates, 42% of the Puerto Rican women and 26% of the African American women reported they engaged in AI at least once and that the behavior was more likely to occur with “serious” than “casual” partners (Carter, Henry-Moss, Hock-Long, Bergdall, & Andes, 2010). Among clients attending STI clinics in Los Angeles County in 2006-07, 14% of the white women, 13% of the Hispanic women, and 8% of the African American women engaged in AI in the past 90 days (Javanbakht et al., 2010). The results of these studies, including our own, cannot be directly compared because of demographic and methodological differences. Taken as a whole, however, the findings indicate that AI is practiced among some heterosexual women regardless of race or ethnicity.

Despite the relatively high percentage of women in our sample who engaged in sexual behaviors that put them at risk, we found only two cases (0.13%) of unrecognized HIV infection among our 1527 participants. One possible explanation is that the absence of reported HIV infected sexual partners may account for the low percentage of unrecognized infection. The entry of HIV infected men into these women’s sexual networks would increase their risk for acquiring HIV if they continue to engage in high-risk sexual behaviors, especially UAI. A second explanation might be that women who feared or suspected that they were HIV infected did not present for study screening. The perceived social, economic, and health-related risks of being diagnosed with a stigmatized disease might have discouraged these women from coming forward for screening.

UAI was associated with other high-risk activities such as binge drinking, ever having engaged in exchange sex, and UVI. We also found that prior pregnancy increased the odds of engaging in UAI (in FL and AL, but not NC), which may indicate that some women may have used AI as a birth control method or that AI was introduced early as a birth control method and it became part of their sexual repertoire. Other studies have found that in addition to pregnancy prevention (Halperin, 1999; Maynard et al., 2009; McBride & Fortenberry, 2010), motivations for AI include pleasure seeking (Carter et al., 2010; Maynard, Carballo-Dieguez, Ventuneac, Exner, & Mayer, 2009), sexual experimentation (Gorbach et al., 2009), intimacy (Carter et al., 2010; Maynard et al., 2009), shifting cultural norms (Halperin, 1999; McBride & Fortenberry, 2010), avoiding vaginal sex during menses (Frederick et al., 2009; Hensel, Fortenberry, & Orr, 2010; Mackesy-Amiti, Mckirnan, & Ouellet, 2010), and power relationships (Halperin, 1999; Koblin et al., 2010; Mackesy-Amiti et al., 2010).

The correlates of UAI we identified in heterosexually active women of color in non-urban areas of Alabama and North Carolina and in south Florida are similar to correlates identified in higher-risk women residing in large cities. A study of 436 high-risk (i.e., resided or had social connections in areas with both high prevalence of HIV infection and poverty) heterosexual women in New York City found that UAI was associated with five risk factors: frequent drug use, binge alcohol use, partnerships with incarcerated men, exchange sex partnerships, and multiple partnerships (Jenness et al., 2010). A study of women attending 13 public STI clinics in Los Angeles County found that three factors were associated with AI among women of diverse race/ethnicity: having both male and female sex partners, exchange of drugs or money for sex, and substance use (Javanbakht et al., 2010). Among African American women specifically, those who reported exchange of drugs or money for sex and anonymous sex were more likely to report AI within 90 days preceding their clinic visit (Javanbakht et al., 2010).

These findings, coupled with our own, point to specific risk factors that need attention in behavioral interventions for women and their male partners. Additionally, characteristics of our sample present important considerations for such interventions. First, 21% of our participants reported binge drinking. Comprehensive risk-reduction interventions for women and men should give attention to alcohol use, particularly binge drinking, as a risk factor for unsafe sexual practices. Second, most of our participants (69%) reported a single male partner in the past 12 months. Compared with women reporting multiple sexual partners, women with a single partner were 3.6 times (68% vs.19%) more likely to report UVI and almost 8 times (23% vs. 3%) more likely to report UAI. Moreover, among women with a single partner, 27% reported that they thought that their partner that was “probably” or “definitely” having concurrent sexual relations with another woman. Our findings suggest that interventions would benefit from including focused messages about sexual risk within the context of an ongoing relationship where partner exclusivity is desired or intended. Further, researchers should strive for a better understanding of the relationship dynamics that may promote AI among heterosexual men and women. As others have noted, interventions for heterosexual women need to devote more attention to AI as a risk factor for HIV infection (Brody & Potterat, 2004; Halperin, 1999; Martino, Collins, Elliott, Kanouse, & Berry, 2009; Potterat, Brewer, & Brody, 2008; Risser, Padgett, Wolverton, & Risser, 2009).

In clinical settings, inquiring about AI should be a standard practice in assessing risk behaviors among women. After establishing that a woman is sexually active, it is important to ask questions about the specific types of sexual activities that are taking place, including AI. Answers to these questions can help identify who would benefit most from educational messages about AI, risk-reduction counseling, and screening for anorectal STIs (e.g., human papillomavirus, gonorrhea, Chlamydia). Such screening occurs infrequently among women (Javanbakht et al., 2010). HIV testing may also be needed.

Our study had limitations. The African American women in our sample were from rural counties and included a large number of women with lower income. The Hispanic women were from one urban county in southern Florida and were predominately foreign-born. The county in southern Florida has a unique mix of Cuban, Caribbean, South American and Central American ancestries, which may not represent Hispanic women residing elsewhere. Our use of convenience sampling does not permit estimation of the prevalence of sexual and other risk behaviors in the larger communities from which the women were recruited. Further, because women were asked highly sensitive questions about their own and their partners' behaviors it is possible that some women may have misreported some of their sexual behaviors. Encouragingly, relatively few refused to answer these questions and ACASI has been shown to be an effective tool for collecting sensitive data (Ghanem, Hutton, Zenilman, Zimba, & Erbelding, 2005; Kurth et al., 2004; Rogers et al., 2005). Some women may have under-reported their participation in AI due to the potentially stigmatizing nature of that behavior.

In conclusion, our study found that a relatively high percentage of African American women residing in rural counties in North Carolina and Alabama and Hispanic women from an urban county in southern Florida engaged in sexual behaviors including UAI, which placed them at increased risk for HIV infection. Clinicians should ask their female patients about AI and should conduct anorectal STI screening as well as HIV testing when indicated. More research is needed to understand the motivations and reasons for engaging in AI and to elucidate the interpersonal dynamics that promote the practice among heterosexual African American and Hispanic women. Such information will help guide the development of educational messages and the design of behavioral interventions to reduce the risks of heterosexual AI among women and their male partners. Most behavioral interventions have focused on women and men residing in large urban areas. More attention is needed to those residing outside of major cities, especially in the southeastern U.S.