Prospective cohort study of children exposed to Hepatitis C virus through a pregnancy screening program

OBJECTIVES: Porto Alegre, in south Brazil, has one of the highest Hepatitis C virus (HCV) infections rate in the country (84.4 cases/100,000 in 2018). Prenatal screening of HCV, however, has not been routinely offered. METHODS: We conducted a longitudinal study of pregnant women with HCV and their infants between January 2014 to December 2018. Screening for HCV antibodies was offered to all women delivering at our tertiary institution. HCV RT-PCR was performed if seropositive. Infants were followed prospectively. RESULTS: Among 18,953 pregnant women delivering, 17,810 were screened for HCV antibodies (93.9%) with 130 positive results. (HCV seroprevalence 0.7%). HCV RNA was detectable in 57/117 cases (48.7%). HCV viremia was associated with use of injectable drugs (p=0.03), inhaled/crack drug use (p=0.02), an HCV-seropositive partner, ≥3 lifetime sexual partners (p=<0.01). Genotype 1 was most prevalent (68%) during pregnancy. Among 43 children with follow-up, 6 (13%) were HCV infected (transmission rate 13.9%); genotype 3 infected 50%. Two infants (33%) cleared infection; mothers had genetic polymorphisms associated with clearance. CONCLUSION: HCV vertical transmission was high in our population, with HCV infection during pregnancy being vastly underdiagnosed. Public health efforts must focus on this vulnerable population for disease prevention and early treatment.