This study (American Journal of Epidemiology, 155 (7), 645-53, April 1, 2002) demonstrates women in urban areas tend to have higher rates of HCV and engage in certain risky behaviors. The likelihood of having HCV tended to increase for women who use IV drugs and have sex for money/drugs. The study found women with HSV-2 (suggesting this could also be true for syphillis & other STDs) may have higher risk for getting HCV. Women with low income appear to be more likely to engage in these risky behaviors. This study found that African-Americans were more likely to engage in these baviors and to have HCV. An HCV prevention program should be launched to target these women.

The study authors (Kimberly Page-Shafer, University of California-SF) evaluated risk for hepatitis C virus (HCV) infection in women residing in low-income neighborhoods of northern California. A sample of 1707 women, aged 18 to 29, were surveyed and screened for sexually transmitted infections and HCV. Women infected with HCV (2.5%) were more likely to have a history of injection and noninjection drug use, to exchange sex for money or drugs, and to have sexually transmitted infections. 1.8% of the US general population are HCV-infected. And its unofficially estimated that the rate for women is <1%. HCV was independently associated with history of injection drug use, herpes simplex virus type 2 (HSV-2) infection, and heroin and cocaine use. Injection drug use is the highest risk exposure for HCV, but HSV-2 and noninjection drug use contribute significantly to increased risk. HCV prevention programs in impoverished areas should integrate drug treatment and sexually transmitted infection control.

Sexual Transmission
High rates of sexually transmitted infections and HCV coinfection among IDUs suggest that ulcerative or nonulcerative urogenital infections may be cofactors for HCV transmission. However, investigation of sexually transmitted infections as potential cofactors for sexual transmission of HCV is hampered by the confounding effects of concomitant high-risk sexual behavior and injection practices.18 Lack of data on the determinants of sexual transmission of HCV has limited the development of guidelines for sexual partners who may be at risk for transmitting or acquiring HCV.

The current study examined HCV in the Young Women's Survey, a population-based sample of young women recruited in low income, multiethnic neighborhoods of northern California. Analysis focused on sexual behavior and sexually transmitted infections as risk factors for HCV and their associated population attributable fractions. The Young Women's Survey was a single-stage, cluster-sample, population-based, door-to-door, cross-sectional survey designed to measure the prevalence of HIV, sexually transmitted diseases, and related risk behavior in young, low-income women in northern California.

RESULTS
The population-based estimate of HCV prevalence among women aged 18 to 29 years in low-income neighborhoods of the 4-county target area was 2.5%. More than a third (39.2%) of the subjects were African American, 31.9% were Latina, 15.4% were White, 6.7% were Asian or Pacific Islander, and 6.7% indicated other or mixed race/ethnicity. Most women (70.5%) were born in the United States; 16.9% were born in Mexico, and 12.5% were born in other countries. The median age was 23.9 years.

The prevalence of HCV varied significantly by county of residence, income level, and race/ethnicity. HCV prevalence was highest in the 2 most urban counties: San Francisco (4.3%) and Alameda (3.8%). HCV prevalence increased with decreasing income, reaching 5.1% among women in the lowest income category (< $500 per month). By race/ethnicity, HCV prevalence was highest among African Americans (4.0%).

Prevalence of HCV was significantly higher among women with serologic markers for infection with syphilis (18.3%), HSV-2 (4.2%), HBV (8.3%), and HIV (63.5%). Prevalence of HCV increased with increasing number of lifetime male sexual partners, from 0.4% among women with 1 partner to 3.9% among women with 5 or more partners.

Other sexual risk behaviors associated with increased HCV prevalence were sex with an IDU (12.6%), exchange sex (trading sex for money, drugs, or other needs) (13.6%), and ever having anal sex.

Having had sex while high on alcohol increased likelihood of women having HCV by 2.6 times. HCV prevalence was significantly higher among women reporting use of amphetamine, cocaine, or heroin compared with women not using these drugs. For each of these drugs, HCV prevalence was higher among those reporting injecting compared with those not injecting.

The strongest independent associations with HCV infection were history of injection drug use (OR = 4.9), serological evidence of HSV-2 infection (OR = 3.7), any use of heroin (OR = 5.6), any use of cocaine (OR = 3.40, and very low income (for income < $500 per month OR= 4.2). Sexual risk behavior did not reach statistical significance in the model. African American women were most likely to have HSV-2 infection, to have lower income, and to report a history of trading sex for drugs or money and thus were at highest risk for HCV infection. The adjusted odds ratio for HCV infection associated with HIV infection was 7.5.

Discussion by Authors
The 2.5% prevalence of HCV infection in this population-based survey of young, lowincome women was higher than that reported in a national sample of women, in which prevalence was of 1.2% overall1 and 0.6% among women aged 20 to 29 years (M. Alter, PhD, personal communication, 2000). HCV infection was most highly associated with a history of injection drug use, although noninjection use of heroin and cocaine persisted as independent risk factors. HCV transmission has been hypothesized to occur through sharing of straws or other devices that deliver the virus to hyperemic and traumatized nasal mucosa. Very low income was the strongest socioeconomic correlate of HCV infection. Of particular note, HSV-2 infection was independently associated with HCV infection.

The independent association of anti-HCV with HSV-2 infection suggests a possible cofactor for sexual transmission or acquisition of HCV. As has been hypothesized with HIV, HSV-2 infection may serve to increase the efficiency of sexual acquisition of HCV infection through enhanced viral reproduction or by providing a portal of entry through ulceration or inflammation. The cross-sectional design of this study, however, precludes confirmation of this hypothesis and limits causal inference.

A similar association between HCV and HSV-2 was shown in a study of heterosexual couples who were HCV serodiscordant.24 Alter et al.1 found that HCV infection was associated with HSV-2 infection in the National Health and Nutrition Examination Survey III study in analyses controlling for age but not for drug use and high-risk sexual behaviors. Similarly, in a recent study among drug users in treatment, Hwang et al.25 found no association between HCV and HSV-2 after controlling for the confounding effects of injection history and sexual risk.

Despite study limitations, our data provide rare population-based estimates of HCV prevalence and related risk factors among young, low-income women. Understanding the epidemiology of HCV infection among women in low-income neighborhoods is a critical first step in designing primary and secondary interventions to mitigate the morbidity and mortality of this emerging infection. The growing evidence linking HSV-2 to HIV and HBV15Ð17,29 points to a potential role for HSV-2 as a cofactor in sexual transmission of HCV as well. Strong empirical evidence supports the efficacy of sexually transmitted infection control as a means of reducing HIV risk through clinical and behavioral intervention.15 Prevention of sexual transmission of HCV should be considered from a similar public health perspective. Although the per-contact likelihood of HCV transmission may be lower than through syringe sharing, a large and growing pool of carriers may generate significant numbers of new infections through sexual intercourse. Because many of the risk factors responsible for HCV infection are also related to risk of other adverse health outcomes, public health efforts aimed at reducing drug use and sexual risk vulnerability in very-low-income women should have multiple positive results.