Prospective cohort study of mother‐to‐infant infection and clearance of hepatitis C in rural Egyptian villages

Although persistent transmission of hepatitis C virus (HCV) from infected mothers to their infants is reported in 4–8%, transient HCV perinatal infection also occurs. This prospective cohort study determined perinatal HCV infection‐ and early and late clearance‐rates in 1,863 mother‐infant pairs in rural Egyptian villages. This study found 15.7% and 10.9% of pregnant women had HCV antibodies (anti‐HCV) and HCV‐RNA, respectively. Among 329 infants born of these mothers, 33 (10.0%) tested positive for both anti‐HCV and HCV‐RNA 2 months following birth—29 (12.5%) having HCV‐RNA positive mothers and 4 (with transient infections) having mothers with only anti‐HCV. Fifteen remained HCV‐RNA positive at one and/or 2 years (persistent infections), while 18 cleared both virus and antibody by 1 year (transient infections). Among the 15 persistent cases, 7 cleared their infections by 2 or 3 years. At 2‐ to 6‐ and at 10‐ to 12‐month maternally acquired anti‐HCV was observed in 80% and 5% of infants, respectively. Four perinatally infected and one transiently infected infant were confirmed to be infected by their mothers by the sequence similarity of their viruses. Viremia was 155‐fold greater in mothers of infants with persistent than mothers of infants with transient infections. Maternal‐infant transmission of HCV is more frequent than generally reported. However, both early and late clearance of infection frequently occurs and only 15 (4.6%) and 8 (2.4%) infants born of HCV‐RNA positive mothers had detectable HCV‐RNA at one and 2–3 years of age. Investigating how infants clear infection may provide important information about protective immunity to HCV. J. Med. Virol. 81:1024–1031, 2009. © 2009 Wiley‐Liss, Inc.