{
 "topic": "Hepatitis C Virus Infection",
 "slug": "hepatitis-c-virus-infection",
 "category_id": 14948,
 "summary": "Vertical transmission risk factors for pediatric HCV, why breastfeeding remains safe, the typically indolent childhood course, and the shift to curative oral antiviral therapy.",
 "written_by": "claude-sonnet",
 "references": [
  {
   "title": "Red Book Atlas of Pediatric Infectious Diseases",
   "author": "American Academy of Pediatrics,Carol J. Baker, MD, FAAP",
   "pages": [
    246,
    247
   ]
  },
  {
   "title": "Practical Algorithms in Pediatric Gastroenterology (Ron Shaoul)",
   "author": "meiersa",
   "pages": [
    86
   ]
  },
  {
   "title": "Berkowitz's Pediatrics",
   "author": "Berkowitz, Carol D.;",
   "pages": [
    973,
    974
   ]
  },
  {
   "title": "The Harriet Lane Handbook (The Johns Hopkins Hospital)",
   "author": null,
   "pages": [
    539
   ]
  },
  {
   "title": "The Harriet Lane Handbook 22nd Edition (2020) (The Johns Hopkins Hospital)",
   "author": null,
   "pages": [
    539
   ]
  },
  {
   "title": "Illustrated Textbook of Paediatrics (Tom Lissauer, Will Carroll)",
   "author": "Lissauer, Tom,Carroll, Will",
   "pages": [
    392
   ]
  },
  {
   "title": "Ghai Essential Pediatrics, 9e (Vinod K Paul, Arvind Bagga)",
   "author": "CamScanner",
   "pages": [
    227
   ]
  },
  {
   "title": "Gomella's Neonatology: Management, Procedures, On-Call Problems, Diseases, and Drugs, Eighth Edition",
   "author": "Tricia Lacy Gomella, Fabien G. Eyal and Fayez Bany-Mohammed",
   "pages": [
    1167
   ]
  }
 ],
 "short": [
  {
   "title": "In short",
   "content": "- HCV is a single-stranded RNA flavivirus with at least 7 genotypes and a high mutation rate that helps it escape immune detection. It causes 20\u201340% of adult viral hepatitis; pediatric prevalence is roughly 0.1\u20130.2% of children (0.4% of adolescents, 1.5% of adults in the US).\n- Maternal-fetal (vertical) transmission is the most common route of pediatric infection, occurring in about 5\u20136% of pregnancies from HCV RNA-positive mothers; transmission occurs only from mothers viremic (RNA-positive) at delivery.\n- Maternal HIV coinfection roughly doubles to triples the vertical transmission risk (to about 10\u201320%, vs 5\u20136% without HIV coinfection) \u2014 attributed partly to higher maternal HCV RNA levels from HIV-related immunosuppression.\n- Other perinatal risk factors: prolonged rupture of membranes (>6 hours before delivery) and invasive obstetric procedures (amniocentesis, fetal scalp electrode monitoring) may increase transmission risk; cesarean delivery does NOT reduce transmission risk except when the mother is HIV-coinfected.\n- Breastfeeding is considered safe and is not restricted \u2014 HCV RNA can be detected in colostrum, but transmission risk is similar between breastfed and formula-fed infants.\n- Post-transfusion HCV risk is now extremely low in the US (~1 per 2 million units transfused) due to donor exclusion and antibody screening since 1992; before 1992, HCV caused up to 90% of post-transfusion hepatitis.\n- Acute HCV infection is usually mild, insidious, and often asymptomatic \u2014 jaundice occurs in under 20% of patients, with milder transaminase abnormalities than hepatitis B. Signs/symptoms are indistinguishable from hepatitis A or B when present.\n- Chronic infection develops in up to 80% of infected children (versus 70\u201380% of infected adults), but children usually have a more indolent course with less frequent progression to cirrhosis or hepatocellular carcinoma than adults; HCV-related liver failure is nonetheless the leading indication for liver transplantation among US adults. Lifetime risk of progression to cirrhosis/hepatocellular carcinoma is cited as 20\u201325%.\n- Diagnosis in infants of infected mothers requires waiting for maternal HCV antibody to clear (since it persists 12+ months in the infant from passive transfer) \u2014 check HCV antibody at 18 months of age, and monitor ALT in the interim.\n- New oral direct-acting antivirals (e.g., sofosbuvir) approved for ages 12 years and up are highly effective (potentially close to 100% curative), a major advance over the older pegylated interferon plus ribavirin regimen; treatment is generally deferred until after age 3, since HCV acquired vertically can resolve spontaneously in some children before then."
  }
 ],
 "long": [
  {
   "title": "Definition",
   "content": "Hepatitis C virus (HCV) is a single-stranded RNA virus in the Flavivirus family, with at least seven identified genotypes and a high mutation rate that allows it to evade host immune detection, contributing to its tendency toward chronic infection. HCV is the most common cause of non-hepatitis-B chronic viral hepatitis."
  },
  {
   "title": "Epidemiology",
   "content": "HCV accounts for 20\u201340% of all viral hepatitis in adults. Prevalence estimates in the United States are approximately 0.1\u20130.2% of children, 0.4% of adolescents, and 1.5% of adults with serologic evidence of infection. In adults and adolescents, recognized risk factors include intravenous drug use, occupational or sexual exposure, and receipt of blood products before 1992; about one-third of young adults (18\u201330 years) who inject drugs in the US have HCV infection. In children, maternal-fetal (vertical) transmission is now the most common route of infection, occurring in roughly 5\u20136% of pregnancies with an HCV-positive mother; seroprevalence among pregnant women in the US is estimated at 1\u20132%. Post-transfusion HCV, historically responsible for up to 90% of post-transfusion hepatitis before donor screening began in 1991, now carries a risk of well under 1 per 2 million transfused units in the US due to donor exclusion and antibody/RNA-pool screening. No identifiable source of infection is found in at least 35% of cases overall."
  },
  {
   "title": "Etiology",
   "content": "HCV is spread primarily by parenteral exposure to infected blood. In children, maternal-fetal transmission predominates; transmission occurs only from mothers who are HCV RNA-positive (viremic) at the time of delivery, and maternal HIV coinfection increases transmission risk 2- to 3-fold (from about 5\u20136% to about 10\u201320%), likely because HIV-mediated immunosuppression raises maternal HCV RNA levels. Prolonged rupture of membranes (more than 6 hours before delivery) and invasive obstetric procedures such as amniocentesis or fetal scalp electrode monitoring may further increase transmission risk. Mode of delivery (cesarean vs. vaginal) does not reduce transmission risk except when the mother is HIV-coinfected. Although HCV RNA can be detected in colostrum, breastfeeding is considered safe, since transmission rates are similar in breastfed and formula-fed infants. Beyond vertical transmission, other pediatric risk groups include dialysis patients, institutionalized children, and high-risk newborns (maternal IV drug use, maternal STIs, maternal HIV coinfection); in adolescents, IV drug use and sexual contact become more relevant routes, similar to adults."
  },
  {
   "title": "Clinical features",
   "content": "Acute HCV infection is typically mild and insidious in onset, and most infections are asymptomatic; when present, signs and symptoms are indistinguishable from hepatitis A or B. Jaundice occurs in fewer than 20% of patients, and serum aminotransferase elevations are generally less pronounced than in hepatitis B. Persistent (chronic) infection develops in up to 80% of infected children, frequently without biochemical evidence of ongoing liver disease, and most chronically infected children remain asymptomatic. This contrasts somewhat with adults, in whom chronic hepatitis develops in about 70\u201380% of infections but tends to run a less indolent course than in children, with cirrhosis and hepatocellular carcinoma more commonly reported in adult series; the lifetime risk of progression to cirrhosis or hepatocellular carcinoma is cited at roughly 20\u201325%. HCV-related liver failure is nonetheless the leading indication for liver transplantation among adults in the United States, underscoring the long-term stakes of chronic pediatric infection carried into adulthood. Incubation period averages 6\u20137 weeks (range 2 weeks to 6 months), with viremia detectable 1\u20132 weeks after exposure."
  },
  {
   "title": "Diagnostics",
   "content": "In infants born to HCV-infected mothers, diagnosis must account for passively transferred maternal antibody, which can persist in the infant for 12 or more months; HCV antibody testing is therefore deferred until 18 months of age, with ALT monitored in the interim as a nonspecific marker of hepatic inflammation. For infants at particular risk (e.g., maternal HIV coinfection, maternal IV drug use), earlier virologic (HCV RNA) testing can be considered per current guidelines, though antibody testing at 18 months remains the standard confirmatory approach in a field that continues to evolve."
  },
  {
   "title": "Treatment",
   "content": "Treatment of pediatric HCV has changed substantially with the availability of oral direct-acting antiviral regimens (such as sofosbuvir-based combinations), which have largely replaced the older standard of pegylated interferon plus ribavirin and offer cure rates approaching 100% in appropriate candidates; these newer regimens are approved for children 12 years and older. Because HCV acquired via vertical transmission can resolve spontaneously in some young children, treatment is generally not initiated before age 3, allowing time for possible spontaneous clearance before committing to antiviral therapy. The increasing efficacy and tolerability of oral regimens has heightened the importance of screening high-risk children \u2014 notably children of mothers who inject drugs \u2014 so that eligible candidates for cure are identified rather than missed."
  }
 ],
 "clinical": [
  {
   "title": "Management approach",
   "content": "For an infant born to an HCV-infected (HCV RNA-positive) mother, plan a structured follow-up rather than testing immediately: monitor ALT periodically in infancy, and check HCV antibody at 18 months of age once passively transferred maternal antibody has had time to clear (it can otherwise persist and produce a false-positive result for up to 12+ months). Counsel the mother that breastfeeding is safe and should not be discouraged on the basis of HCV status alone, since transmission risk is equivalent between breastfed and formula-fed infants despite detectable HCV RNA in colostrum. During delivery, be aware that prolonged rupture of membranes and invasive obstetric monitoring/procedures may modestly increase transmission risk, but that cesarean delivery is not protective except specifically in HIV-HCV coinfected mothers, so mode of delivery should not be altered for HCV status alone.\n\nIf a child is diagnosed with chronic HCV infection, reassure the family that the pediatric course is generally more indolent than in adults, with lower rates of progression to cirrhosis or hepatocellular carcinoma in childhood, but also explain the long-term stakes (HCV-related liver failure is the leading cause of adult liver transplantation in the US) to support engagement with monitoring and eventual treatment. Defer antiviral treatment until after age 3, since spontaneous clearance can still occur in young children with vertically acquired infection; from age 12 onward, refer for evaluation for oral direct-acting antiviral therapy, given cure rates approaching 100% with these newer regimens. Proactively screen high-risk children \u2014 particularly those born to mothers who inject drugs or who are HIV-coinfected \u2014 since they carry the highest transmission risk (10\u201320% with maternal HIV coinfection) and stand to benefit most from early identification and eventual curative treatment."
  }
 ]
}