We have read with great interest Tohme and Holmberg's review1 in HEPATOLOGY on the sexual transmission of hepatitis C virus (HCV). They distinguished between heterosexual and homosexual contacts and also between monoinfected and human immunodeficiency virus (HIV)–coinfected patients, and they affirmed the recently reported increasing incidence of HCV infection among HIV-positive men who have sex with men.
We analyzed the risk factors for infection in a series of 886 consecutive patients [median age = 40 years, interquartile range = 33-53 years, 521 males (58.8%)] with chronic hepatitis C who were followed up in our liver unit; 198 of these patients (22.3%) were HIV-coinfected. A risk-factor questionnaire was prospectively collected by the members of the unit (i.e., us). We considered the risk factor for HCV infection to be sexual exposure (SEXEXP) only in patients who fulfilled the following criteria: (1) a negative history for intravenous drug use (IDU), inhalatory drug use (INHDU), or blood transfusions (BTs) before 1994 and (b) a sexual partner who was recognized to be anti-HCV–positive.
The main risk factors in the whole group of patients were IDU (32.5%), BTs (19.4%), INHDU (8.9%), and SEXEXP (8.6%). In 20.2% of the patients, no risk factors were identified. However, we found significant differences in the risk factors between males and females [the main ones were IDU (47.4%) and BTs (30.5%), respectively; SEXEXP was considered to be the probable risk factor in only 1.7% of men but in 18.3% of women (P = 0.0000)]. There were also significant differences between monoinfected HCV patients (n = 687, age = 46 ± 14 years) and HIV-coinfected patients (n = 198, age = 35 ± 6 years). In the first group, 24.4% had a history of BTs, 23.5% had a history of IDU, and 9.1% had a history of INHDU; in the second group, a history of IDU was predominant (62.1%), and it was followed by SEXEXP (20.5%).
In our opinion, the more interesting finding is the relationship between females (n = 365) and SEXEXP as the probable route of HCV transmission. The definition of SEXEXP was fulfilled by 10% of monoinfected women (n = 292, age = 51 ± 15 years), whereas in the group of HIV-coinfected women (n = 73, age = 35 ± 7 years), the percentage was more impressive: 49%. Although this subgroup of coinfected women is small, it seems to us that this finding is worthy of being reported. The sexual partners of these women are also our patients; most have the same HCV genotype as their wives, and they usually have a history of IDU. Thus, we have to rely on clinical histories to exclude this background in women. In conclusion, we have found SEXEXP to be a very prevalent risk factor for HCV infection in HIV-coinfected women. The transmission of HCV might be secondary to high viremia levels in their partners in the period before antiretroviral treatment. This result should be further addressed in a larger population.