Background:  Observational studies suggest that maternal HIV/hepatitis C virus (HCV) co-infection is associated with increased odds of vertical HCV transmission. The aim of this study has been to assess the prevalence and natural history of HCV in a large cohort of HIV-infected mother and to describe vertical transmission of HCV.
Methods:  A prospective cohort study was initiated in 2000 at 8 hospitals in Madrid. All mothers who delivered until December 2005 were included, and mothers’ and infants’ data recorded. Duration of infant follow-up ranged from 18 to 36 months. Statistical analyses were carried out using SPSS 14.0.
Results:  Among the 631 mothers enrolled, 271 were HCV/HIV co-infected (42.9%); 319 were not (50.6%); and HCV status was unknown in 41 (6.4%). Compared with mono-infected HIV patients, mothers co-infected had a higher mean age at entry (30.1 vs 33.1 years, p <0.001), a longer period of awareness of HIV infection (8.2 vs 4.7 years, p <0.001), were classified under stage C of the Centers for Disease Control and Prevention (CDC) AIDS criteria more frequently (24.8% vs 12.5%, p <0.002), and had received ART before pregnancy in a higher percentage (61.6% vs 41.4%, p <0.001). Co-infection was more frequent in the parenteral transmission than in the sexual transmission group (74.9% vs 10.3%, p <0.001). There were no differences between mono- and co-infected mothers in terms of mode of delivery, caesarean section being the most frequent mode in both (70.4% vs 70.6%). Vertical transmission of HCV was 2.6% (7 of 271, CI95% 2.52 to 2.63), whereas for HIV it was 1.4% (9 of 631; CI95% 1.38 to 1.45). There were no HCV/HIV-co-infected infants. Mothers from HCV-infected children had a median CD4⁺ and viral load at the third trimester equal to 453 cells/mm³ and 50 copies/mL respectively; 83.3% of mothers were included in category A/B and 16.7% in category C. The 7 mothers received effective ART during pregnancy, 71.4% HAART without a protease inhibitor (PI) and 28.6% HAART with PI.
Conclusions:  HCV/HIV-co-infected mothers were predominantly infected by parenteral transmission, had a longer period of HIV infection, and a higher CDC stage. There is a high prevalence of HVC/HIV co-infection, but there were no cases of vertical transmission of HCV/HIV. HCV infection was detected in 2.6% of infants who were born to dually infected mothers. This rate is less than others recently reported (>5%).