1Hospital da Criança Conceição, Porto Alegre, RS, Brazil.
2University of San Diego School of Medicine, University of California, San Diego, California, USA.
3Western Michigan University, Homer Stryker M.D. School of Medicine, Kalamazoo, Michigan, USA.
4David Geffen School of Medicine, University of California, Los Angeles, California, USA.
5Communicable Disease Surveillance Team, Municipal Health Secretariat of Porto Alegre, RS, Brazil.
6Hospital Nossa Senhora da Conceição, Porto Alegre, RS, Brazil.
7Central Public Health Laboratory of Rio Grande do Sul, Porto Alegre, RS, Brazil.
8David Geffen School of Medicine, University of California, Los Angeles, California, USA. Electronic address: firstname.lastname@example.org.
Objectives: Porto Alegre, in south Brazil, has one of the highest hepatitis C virus (HCV) infection rates in the country (84.4 cases/100 000 in 2018). Prenatal screening of HCV, however, has not been routinely offered.
Methods: A longitudinal study of pregnant women with HCV and their infants was conducted between January 2014 and December 2018. Screening for HCV antibodies was offered to all women delivering at the study tertiary institution. HCV RT-PCR was performed if the woman was seropositive. Infants were followed prospectively.
Results: Among 18 953 pregnant women delivering infants during the study period, 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 the use of injectable drugs (P = 0.03), inhaled/crack drug use (P = 0.02), having an HCV-seropositive partner, and ≥3 lifetime sexual partners (P < 0.01). Genotype 1 was most prevalent (68%) during pregnancy. Among 43 children with follow-up, six (13%) were HCV-infected (transmission rate 13.9%); 50% were infected with genotype 3. Two infants (33%) cleared their infection; the mothers had genetic polymorphisms associated with clearance.
Conclusion: HCV vertical transmission was high in the study population, with HCV infection during pregnancy being vastly underdiagnosed. Public health efforts must focus on this vulnerable population for disease prevention and early treatment.