8, 95% confidence interval [CI] 1.1-6.9) more likely to acquire HCV than women with only one steady partner. 42 Data regarding heterosexual transmission of hepatitis C should be interpreted with caution, however. Three large Italian cross-sectional studies showed that the risk of spousal transmission could also be explained by the common practice of sharing syringes. 25, 30, 36 Furthermore, a recent analysis of acute HCV infections in the United States has indicated that increased numbers of sexual partners correlates with increased likelihood of injection drug use (Monina Klevens, Centers for Disease Control and Prevention,

unpublished data). The presence of preexisting STIs has also been found to increase the risk of acquiring HCV by heterosexual contact. 46, 47 A cross-sectional study in India Hydroxychloroquine concentration showed that men infected with herpes simplex virus 2 were almost four times more likely to have HCV than men without herpes Ceritinib solubility dmso simplex virus 2 infection (aOR 3.85, 95% CI 1.18- 12.6). 47 Similarly, individuals with Trichomonas infection were much more likely to acquire HCV than individuals without an STI (aOR 3.3, 95% CI 1.7-6.3). 46 More unequivocal is the risk of heterosexual

transmission to those who are infected with HIV. Two cross-sectional studies confirm a substantial increase in risk of acquiring HCV infection among heterosexual persons with preexisting HIV, particularly among those engaging in high-risk sexual

behaviors and having unprotected sex with multiple sexual partners (Table 1). 48, 49 Notably, the large Women’s Interagency HIV Study found that, controlling for IDU, HIV-infected women were still almost twice as likely as HIV-negative women to acquire HCV (aOR 1.9, 95% CI 1.2-2.9). 49 Likewise, a cross-sectional study among STD clinic attendees in Baltimore showed a four-fold increase in the risk of HCV infection among HIV-infected patients compared with those MCE公司 who were HIV-seronegative (aOR 4.4, 95% CI 1.9-10.3). 46 In a study of hemophilic men and their partners 23 in which unacknowledged IDU was unlikely to be a confounding variable, 6% of hemophiliac men who were coinfected with HIV compared with only 2% of the men infected with HCV alone transmitted HCV to their spouses. In contrast, a smaller cohort study did not show evidence of sexual transmission of HCV from partners who were both HCV/HIV-coinfected. 22 Incidence rates of HCV infection among HIV-uninfected men who have sex with men (MSM) have varied between zero cases per 100 person-years in Amsterdam 50 to 1.5 cases per 1,000 person-years in the United Kindgdom.