The natural history of hepatitis C virus infection acquired during childhood

Pediatric Hepatitis C Screening by Maternal Hepatitis C Infection Status During Pregnancy

BACKGROUND

Screening for perinatal hepatitis C virus (HCV) infections remains low despite increases in the number of at-risk infants. It is unknown if pediatric screening varies by maternal HCV infection status during pregnancy.

METHODS

Using a retrospective cohort of mother-infant pairs born from 2015 to 2019, we identified women with HCV and classified their infection status during pregnancy as active, probable or previous based on HCV RNA testing obtained during pregnancy. We used logistic regression to assess odds (OR) of infant screening based on maternal HCV infection status.

RESULTS

Of the 503 HCV-exposed infants, 137 (27%) were born to women with previous infection, 106 (21%) to women with probable infection, and 260 (52%) to women with active infection. Completion of pediatric screening varied by maternal infection status (43% previous infection; 49% probable infection; 58% active; p=0.014). Pediatric HCV infection ranged from 1.7-7.7% by maternal VL status. Infants born to women with active infection were 2.5 times more likely (95%CI: 1.5-4.4) to have a screening test ordered versus infants of previously infected women; there was no difference for infants of women with probable infection (OR:1.6; 95%CI: 0.9-3.2). Test ordering was also associated with maternal smoking status, a visit at ≥18 months of age and outpatient documentation of HCV exposure. If a test was ordered, there was no difference in test completion by maternal infection status. However, test completion was associated with living with a non-biologic parent and earlier birth year.

CONCLUSION

Infants born to women with active infection are more likely to be screened for HCV, but many children continue to be unscreened and pediatric HCV infections are going undetected. New Centers for Disease Control and Prevention pediatric HCV screening guidelines recommending earlier screening may improve screening rates.

Epidemiology and Natural History of Childhood-Acquired Chronic Hepatitis C: A Single-Center Long-Term Prospective Study

OBJECTIVES

To prospectively describe the epidemiology and long-term outcome of childhood-acquired hepatitis C virus (HCV) infection in a large cohort of children followed at a single center.

METHODS

All children with chronic HCV infection followed at the Liver Unit of our tertiary Hospital in Florence (Italy) from January 1, 1988, to September 30, 2021, were included in the analysis.

RESULTS

The final sample consisted of 163 children (median age at enrollment 4 years, interquartile range (IQR): 10; median age at last follow-up 14 years, IQR: 7). The median duration of follow-up was 86 months (IQR: 112). One hundred twenty-five children were vertically infected and 26 acquired the infection horizontally. Twenty-six of the 125 children who were vertically infected (20.8%) underwent spontaneous clearance of HCV RNA at a median age of 4 years (IQR: 2), whereas all the others remained persistently viremic. One patient was diagnosed with cirrhosis; 2 presented clinically detectable extrahepatic manifestations (chronic urticaria). Thirty-two children (19.6%) received antiviral therapy: 8 out of 32 (25%) were treated with pegylated-interferon alfa-2b [sustained virological response (SVR) 24 weeks after the end of treatment in 7/8]; 24 out of 32 (75%) were treated with direct-acting antivirals (SVR 12 weeks after the end of treatment in 23/24).

CONCLUSIONS

The present study describes the largest cohort of children with chronic HCV infection prospectively evaluated with a long follow-up at a single center. HCV infection in children is often a chronic infection that can be cured with modern antiviral therapy. Early treatment could prevent the development of advanced liver disease.

Breakthroughs and challenges in the management of pediatric viral hepatitis

Chronic infections by hepatitis B virus (HBV) and hepatitis C virus (HCV) major causes of advanced liver disease and mortality worldwide. Although regarded as benign infections in children, their persistence through adulthood is undoubtedly of concern. Recent advances in HCV treatment have restored the visibility of these conditions and raised expectations for HBV treatment, which is currently far from being curative. Herein we describe direct-acting antivirals available for pediatric HCV (sofosbuvir/ledipasvir, sofosbuvir/velpatasvir, glecaprevir/pibrentasvir) and their real-world use. A critical review of the HBV pediatric classification is provided. Anti-HBV investigational compounds are reviewed in light of the pathophysiology in the pediatric population, including capsid assembly modulators, antigen secretion inhibitors, silencing RNAs, and immune modifiers. Recommendations for screening and management of immunosuppressed children or those with other risk factors or comorbidities are also summarized.

Epidemiology and natural history of hepatitis C virus infection among children and young people

BACKGROUND & AIMS

Chronic hepatitis C virus (HCV) infection is a global health burden. Although HCV infection rarely contributes to morbidity during childhood, most HCV-infected children develop chronic HCV with a lifetime risk of liver disease. Little is known about the development of long-term liver disease and the effect of treatment in patients infected with HCV in childhood.

METHOD

This study was a retrospective review of patients infected with HCV in childhood enrolled in HCV Research UK. A total of 1,049 patients were identified and included.

RESULTS

The main routes of infection were intravenous drug use (53%), blood product exposure (24%) and perinatal infection (11%). Liver disease developed in 32% of patients, a median of 33 years after infection, irrespective of the mode of infection. Therefore, patients with perinatal exposure developed cirrhosis at an earlier age than the rest of the risk groups. The incidence of hepatocellular carcinoma (HCC) was 5%, liver transplant 4% and death occurred in 3%. Overall, 663 patients were treated (55% with interferon/pegylated interferon and 40% with direct-acting antivirals). Sustained virological response (SVR) was achieved in 406 (75%). There was a higher mortality rate among patients without SVR vs. those with SVR (5% vs. 1%, p = 0.003). Treatment was more effective in patients without cirrhosis and disease progression was less frequent (13%) than in patients with cirrhosis at the time of therapy (28%) p < 0.001. Patients with cirrhosis were more likely to develop HCC, require liver transplantation, or die.

CONCLUSION

HCV infection in young people causes significant liver disease, which can now be prevented with antiviral therapy. Early treatment, especially before development of cirrhosis is essential. Detection of HCV should be aimed at relevant risk groups and antiviral therapy should be made available in childhood to prevent long-term liver disease and spread of HCV.

LAY SUMMARY

Chronic hepatitis C virus (HCV) infection is a global health problem, which can now be treated with potent direct-acting antiviral drugs. This study demonstrates that HCV infection in childhood causes serious liver disease in 32% of patients, a median of 33 years after infection, irrespective of age, mode and route of infection. Disease outcomes were better in patients treated before the development of advanced liver disease. Antiviral therapy should be made available in childhood to prevent long-term liver disease and the spread of HCV.

Hepatitis C virus among pregnant women and children in the USA: an emerging epidemic

Hepatitis C virus (HCV) infection is increasing among pregnant women, resulting in an increased prevalence of perinatal exposure and pediatric infection. While antiviral medications have been effective at preventing perinatal transmission of viral infections, such as HIV, there are currently no interventions to prevent the perinatal transmission of HCV. In this review, the epidemiology of HCV, current HCV screening recommendations during pregnancy and existing knowledge gaps for the use of directly acting antivirals (DAAs) medications in pregnancy will be discussed. To address the rapidly changing epidemiology of HCV, consideration should be given to universal screening for HCV during pregnancy and future studies should explore when directly acting antivirals should be used for maternal treatment during pregnancy to prevent perinatal transmission.

Hepatitis C Virus Screening Among Children Exposed During Pregnancy

OBJECTIVES

Because of the opioid epidemic, hepatitis C virus (HCV) infection is increasing among pregnant women, resulting in an increased risk of perinatal transmission and HCV infection among children. Our primary objectives in this study were to determine the prevalence of HCV among pregnant women and the frequency of pediatric HCV screening.

METHODS

A population-based, retrospective cohort of pregnant women who delivered between 2006 and 2014 was identified and classified as HCV infected or HCV uninfected by billing codes. Infant records linked to the HCV-infected pregnant women were identified and queried for HCV tests and the receipt of well-child services, which were defined as the presence of hemoglobin and/or lead testing at or after 9 months of age.

RESULTS

Between 2006 and 2014, 1043 (1.2%) HCV-infected pregnant women delivered, and the HCV prevalence increased by 60%. HCV-infected women were more likely to be <30 years of age (67% vs 53%; P < .001), white (93% vs 72%; P < .001), insured by Medicaid (77% vs 29%; P < .001), and have opiate use disorder (68% vs 1%; P < .001) than HCV-uninfected women. Infants born to HCV-infected women were more likely to be preterm (<37 weeks' gestation; 22% vs 10%; P < .001) and of low birth weight (<2500 g; 23% vs 8%; P < .001). Among 1025 HCV-exposed infants with available pediatric records, 323 (31%) received well-child services, and among these, only 96 (30%) were screened for HCV.

CONCLUSIONS

Despite the increased HCV prevalence among pregnant women and the risk of perinatal HCV transmission, HCV-exposed infants are not adequately screened, and many pediatric HCV infections remain undetected.

Health-related Quality of Life in Adolescent Patients With Hepatitis C Genotype 1 Treated With Sofosbuvir and Ledipasvir

OBJECTIVE

The aim of the study was to assess the effect of treatment with ledipasvir/sofosbuvir (LDV/SOF) on the health-related quality of life (HRQL) of pediatric patients with chronic hepatitis C virus (HCV) infection.

METHODS

Adolescents (12-17 years) with HCV were treated with LDV/SOF (90/400 mg daily) for 12 weeks. HRQL was assessed using the PedsQLv4.0-SF15 completed by the children and caregivers before, during, and after treatment.

RESULTS

We included 100 adolescents with HCV genotype 1 infection (14.7 ± 2.0 years, 1% known cirrhosis, 80% treatment-naïve, 97% sustained virologic response-12). At baseline, HRQL the caregiver- perceived HRQL scores were lower than adolescents' self-reported scores (by 6.7-7.9 points, all P < 0.01). At the end of 12 weeks of treatment, however, the caregiver-reported HRQL scores showed a significant improvement (+all P < 0.04), whereas the adolescents' self-reported scores did not change from the baseline. HRQL scores reported by caregivers remained higher than baseline (by +4.7-+7.5, P < 0.01) through 12 weeks after treatment, as did the adolescents' self-reported Emotional Functioning scores (+4.3 from baseline, P = 0.0009); observed improvements were sustained after 24 weeks of follow-up (all P < 0.04). Multivariate analysis showed that, after adjustment for location, age, and sex, having a history of anxiety and panic disorders were consistent predictors of impaired HRQL in adolescents with HCV infection (P < 0.05).

CONCLUSIONS

Treatment of HCV in adolescents with LDV/SOF is associated with some improvement in HRQL. Caregivers' reports of HRQL in adolescents with HCV significantly increased with treatment and were similar to the adolescent self-reported HRQL after sustained virologic response-12.

Hepatitis C: Review of the Epidemiology, Clinical Care, and Continued Challenges in the Direct Acting Antiviral Era

PURPOSE OF REVIEW

This review highlights key studies and recently published data, policies, and recommendations related to hepatitis C virus (HCV) epidemiology, transmission, and treatment.

RECENT FINDINGS

HCV is a leading cause of liver-related deaths, cirrhosis, and hepatocellular carcinoma. Since 2011 and accelerating since 2013, new, safe, tolerable, and curative therapies have considerably altered clinical and public health frameworks related to the prevention, control and clinical management of HCV. Nevertheless, there are several populations in the United States that are important to consider because of disparities in HCV prevalence and transmission risk. Adults born during 1945-1965 have an estimated anti-HCV antibody prevalence of ~3%, which is six times higher than among other adults, are often unaware of their infections, and are at increased risk of having HCV-associated morbidity and mortality from decades of chronic infection. Since the early 2000s, increasing incidence of acute HCV infections among young, white, non-urban people who inject drugs have been reported. Despite promising therapeutic advances, significant challenges remain for reducing HCV-associated morbidity and mortality.

SUMMARY

The high burden of HCV and significant health consequences associated with chronic infection make HCV a critical public health priority. Advances in HCV treatment have created new opportunities for reducing HCV-associated morbidity and mortality. These treatments are safe, well-tolerated, and highly effective; however, benefits cannot be realized without a significant increase in the number of persons tested for HCV so that all chronically infected individuals can be aware of their diagnosis and linked to appropriate clinical care.

Failure to Test and Identify Perinatally Infected Children Born to Hepatitis C Virus-Infected Women

BACKGROUND

Vertical transmission of hepatitis C virus (HCV) is the most common route of pediatric HCV infection. Approximately 5% of children born to HCV-infected mothers develop chronic infection. Recommendations employ risk-based HCV testing of pregnant women, and screening children at a young age. This study assesses testing rates of children born to mothers tested HCV-positive in a major US city with a high burden of HCV infection.

METHODS

HCV surveillance data reported to the Philadelphia Department of Public Health are housed in the Hepatitis Registry. Additional tests, including negative results, were retrospectively collected. HCV data were matched with 2011-2013 birth certificates of children aged ≥20 months to identify mothers tested HCV-positive and screened children. The observed perinatal HCV seropositivity rate was compared to the expected rate (5%).

RESULTS

A total of 8119 females aged 12-54 years tested HCV-positive and in the Hepatitis Registry. Of these, 500 (5%) had delivered ≥1 child, accounting for 537 (1%) of the 55 623 children born in Philadelphia during the study period. Eighty-four (16%) of these children had HCV testing; 4 (1% of the total) were confirmed cases. Twenty-three additional children are expected to have chronic HCV infection, but were not identified by 20 months of age.

CONCLUSIONS

These findings illustrate that a significant number of women giving birth in Philadelphia test positive for HCV and that most of their at-risk children remain untested. To successfully identify all HCV-infected children and integrate them into HCV-specific care, practices for HCV screening of pregnant women and their children should be improved.

Interferon-α plus ribavirin yields 98 % sustained virologic response in children aged 1-5 years with iatrogenic chronic hepatitis C

BACKGROUND AND OBJECTIVES

The clinical features and efficacies of antivirals for children with hepatitis C virus (HCV) infections that are acquired through different transmission routines are poorly understood worldwide. This study investigated the clinical characteristics of children who were infected via iatrogenic means and analyzed the efficacy of antiviral therapy in children with chronic hepatitis C (CHC).

METHODS

In total, 256 children with HCV infections aged 1 to 5 years were enrolled and surveyed. Interferon-α plus ribavirin was administered to 162 children with CHC for 24 or 48 weeks. The sustained virologic response (SVR) at 24 weeks post-treatment was determined.

RESULTS

The median duration of infection was 11.5 (range 6-24) months. The median age was 2.7 years, and 64.5 % of the subjects were male. Ninety-three children (36.3 %, 93/256) exhibited spontaneous resolution of the HCV infection. The remaining 163 (63.7 %) were HCV RNA-positive and had HCV genotypes 1b and 2a, which were identified in 42 and 58 %, respectively, of the 133 tested children. Liver biopsies were performed in all HCV RNA-detectable children. A total of 23.9 % cases exhibited grade 2 activity, and 30.1 % exhibited stage 2/3 liver fibrosis. The serum HCV RNA levels were positively correlated with the aminotransferases. Of the 162 treated CHC children, 158 (97.5 %) achieved SVR. The side effects were mild, and 158 (97.5 %) of the treated patients tolerated the treatment well.

CONCLUSIONS

This study revealed that histological liver disease can be present within 6-24 months of acquiring an HCV infection in children aged 1-5 years. Interferon-α plus ribavirin therapy is a highly effective and cost-effective means of managing children with early-stage chronic HCV infection.

The clinical effectiveness and cost-effectiveness of peginterferon alfa and ribavirin for the treatment of chronic hepatitis C in children and young people: a systematic review and economic evaluation

BACKGROUND

Optimal therapy for children with chronic hepatitis C is unclear. Two treatment regimens are currently licensed in children.

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of peginterferon alfa-2a (Pegasys®, Roche) and peginterferon alfa-2b [ViraferonPeg®, Merck Sharp & Dohme (MSD)] in combination with ribavirin (RBV), within their licensed indications, for the treatment of chronic hepatitis C virus (HCV) in children and young people aged 3-17 years.

DATA SOURCES

Twelve electronic bibliographic databases, including The Cochrane Library, MEDLINE and EMBASE, were searched from inception to November 2012. Bibliographies of retrieved papers, key hepatitis C websites and symposia and manufacturers' submissions to the National Institute for Health and Care Excellence were also searched, and clinical experts were contacted.

REVIEW METHODS

Systematic reviews of clinical effectiveness and cost-effectiveness were conducted, including studies of health-related quality of life (HRQoL), following standard guidelines to ensure methodological rigour. Clinical effectiveness studies were included if they were in children and young people aged 3-17 years with chronic compensated HCV of any severity, including those with human immunodeficiency virus co-infection and those who were treatment naive or had been previously treated. Eligible interventions were peginterferon alfa-2a or peginterferon alfa-2b, each in combination with RBV, compared against best supportive care (BSC) or against each other, and study designs were randomised controlled trials (RCTs) or non-RCTs, or uncontrolled cohort studies. Outcomes included sustained virological response (SVR) and adverse events. Previously published Markov state-transition economic models of chronic HCV in adults were adapted to estimate the cost-effectiveness of peginterferon alfa-2a and -2b (in combination with RBV), compared with BSC and with one another in children. The model extrapolated the impact of SVR on life expectancy, quality-adjusted life expectancy and lifetime costs. Uncertainty was explored through probabilistic and deterministic sensitivity analyses.

RESULTS

Seven studies [two peginterferon alfa-2a and RBV (Copegus®, Roche), and five peginterferon alfa-2b and RBV (Rebetol®, MSD)] were included in the review of clinical effectiveness. Six were single-arm cohort studies and one was a RCT for which only those data for a single arm met the inclusion criteria. Overall, the studies were relatively small and of generally poor quality. SVR rates ranged from 53% to 66% (peginterferon alfa-2a) and 29% to 75% (peginterferon alfa-2b) (49% to 65% if excluding two studies with very small sample sizes). Rates of non-response and relapse were variable and adverse events were generally mild. No studies of cost-effectiveness or HRQoL in children and young people met the inclusion criteria. HRQoL, utilities and costs of treatment were therefore taken from studies of adults with chronic HCV. From this model, peginterferon alfa (-2a or -2b) in combination with RBV was more effective and had lower lifetime costs than BSC. Peginterferon alfa-2a had slightly lower lifetime costs and higher quality-adjusted life-years than peginterferon alfa-2b; therefore, peginterferon alfa-2b was dominated by peginterferon alfa-2a. Results were robust to changes in the sensitivity analyses.

LIMITATIONS

There were few good quality studies and parameter data had to be taken from adult studies, which is a limitation of the work.

CONCLUSIONS

Treatment of children and young people with peginterferon (alfa-2a or -2b) and RBV may be an effective therapy. Results from the independent Markov model suggest that peginterferon (alfa-2a or -2b) in combination with RBV is cost-effective compared with BSC. However, the available evidence is of poor quality. Future research into the impact of these treatments on growth and quality of life in children and young people is recommended.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012002743.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Outcomes in pediatric hepatitis C transplant recipients: analysis of the UNOS database

HCV may lead to the development of ESLD in late childhood and, consequently, contributes to the need for liver transplantation. The aim of this study was to examine post-transplant outcomes in HCV-positive pediatric patients with ESLD from any cause and to determine the impact of the PELD scoring system, introduced in February 2002, on post-transplant patient and graft survival. A retrospective analysis of the UNOS database from 1994 to 2010 was performed to assess graft and patient survival in pediatric HCV-seropositive liver transplant recipients. Graft survival and patient survival comparing subjects in the pre-PELD era and post-PELD era were analyzed using Kaplan-Meier statistics. Factors associated with survival were identified using Cox regression analysis. Of 120 pediatric HCV transplant recipients, 80 were transplanted in the pre-PELD era and 40 were transplanted post-PELD. Median serum total bilirubin, INR, and creatinine were 4.8 mg/dL, 1.6, and 0.7 mg/dL in the pre-PELD era vs. 5.5 mg/dL, 1.7, and 0.6 mg/mL, respectively, in the post-PELD era (p NS). One-yr graft survival in the pre-PELD vs. post-PELD era was 65.0% and 89.7%, respectively (p < 0.01); corresponding three-yr graft survival was 57.3% vs. 76.2% (p = 0.04). One-yr patient survival in the pre-PELD vs. post-PELD era was 79.0% and 97.5%, respectively (p < 0.01); corresponding three-yr survival was 79.0% vs. 89.4% (p = 0.17). Twenty-eight patients (23.3%) were retransplanted: 24 (30%) in the pre-PELD era (median time to retransplant 272 days) and four (10%) in the post-PELD era (median time to retransplant 586 days). Early follow-up demonstrates a trend toward improved pediatric HCV liver transplant graft and patient survival in the post-PELD era. Superior outcomes may be attributed to pretransplant factors, improved surgical technique and better treatment options for HCV infection.

Polymorphisms in the IFNL3/IL28B gene and hepatitis C: from adults to children

The purpose of the present review is to summarise the current knowledge on the association between single nucleotide polymorphisms (SNPs) in the interferon L3 (IFNL3) gene and hepatitis C virus (HCV) infection in children. Many studies in adults have demonstrated that genetic variation in IFNL3 is a strong predictor of the virological response in treatment-naive patients with HCV genotype 1 who were treated with Pegylated-IFN-α and ribavirin. Genetic variation in IFNL3 is also associated with the spontaneous clearance of HCV. Thus far, few paediatric studies have explored the association between variations in the IFNL3 gene and either spontaneous or treatment-induced clearance of HCV. The CC genotype of the rs12979860 SNP is associated with the spontaneous clearance of HCV in children independently of HCV genotype. Four paediatric studies have shown that both the CC genotype of the rs12979860 SNP and the TT genotype of the rs8099917 SNP are associated with the treatment-induced (IFN monotherapy and Pegylated-IFN-α and ribavirin association) clearance of HCV, while the rs12980275 SNP did not affect the virological response. The possible role of IFNL3 gene variation as a pre-treatment and on-treatment predictor of virological response in children is highly attractive but still undetermined. Further paediatric studies are needed to evaluate if testing for SNPs in IFNL3, either alone or together with other predictors of response to treatment, could be used to direct treatment strategies, including an avoidance of unnecessary protease inhibitor therapy and the duration of treatment.

Liver transplantation in a child with multifocal hepatocellular carcinoma hepatitis C and management of post-transplant viral recurrence using boceprevir

HCV infection is the leading cause of liver transplantation in the adult population in the United States. HCV infection occurs in 0.2-0.4% of the pediatric population and progression to HCC is uncommon. Liver transplantation for HCV in children is rare. In this report, we present a case of pediatric patient with HCV and multifocal HCC at the age of 13 who underwent successful liver transplantation. While good graft function was initially observed, at one month after transplant, he experienced significant hepatitis C recurrence. He was treated with low-accelerating dose regimen antiviral therapy of PEG-IFN and RBV, followed by addition of a protease inhibitor, boceprevir, which led to viral clearance. To our knowledge, this is the first case report describing the post-transplant course of a child transplanted for HCV and HCC, and the first pediatric case report on using the triple therapy for management of post-liver transplant recurrence of HCV. This case report demonstrates the need for increased vigilance of surveillance for HCC during childhood.

Donor PNPLA3 rs738409 genotype affects fibrosis progression in liver transplantation for hepatitis C

The rs738409 G>C single nucleotide polymorphism occurring in the patatin-like phospholipase 3 gene has been identified as a novel genetic marker for hepatic steatosis. Recent studies also associated rs738409 with fibrosis in hepatitis C (HCV). Therefore, we sought to determine the impact of donor and recipient rs738409 genotype on the progression of fibrosis after liver transplantation for HCV. This cohort study included 101 patients infected with HCV who underwent liver transplantation between January 2008, and June 2011. Donor and recipient rs738409 genotypes were determined from donor wedge biopsies and recipient explants. The time to Ishak stage 3 fibrosis, or HCV-related mortality/graft loss was analyzed by the Cox model adjusting for HCV-Donor Risk Index, warm ischemic time, pretransplant Model for Endstage Liver Disease (MELD) and viral load. The rs738409 CC variant was present in 56% of donors and 57% of recipients. The median follow-up period was 620 days. A total of 39 patients developed the primary outcome of ≥stage 3 fibrosis or HCV-related mortality/graft loss, the time to which differed by donor (P = 0.019) but not recipient (P = 0.89) genotype. In the multivariate model, donor GC or GG variants had 2.53 times the risk (95% confidence interval [CI] 1.25-5.02, P = 0.008) compared to CC variants. In the alternative endpoint: stage 3 fibrosis or all-cause mortality/graft loss, the effect of donor genotype was attenuated but remained significant at 1.98 (95% CI 1.11-3.53).

CONCLUSIONS

The rs738409 genotype is an important predictor of posttransplant outcome in HCV. Liver, and not adipocytes, is the site at which this effect occurs. Our finding may be useful in donor selection for liver transplantation with HCV, and may guide decisions regarding early antiviral treatment.

Chronic HCV infection: epidemiological and clinical relevance

Hepatitis C virus (HCV), first recognized as a cause of transfusion-associated acute and chronic hepatitis in 1989, plays a major role as a cause of chronic liver injury, with potential for neoplastic degeneration. It is mainly transmitted by the parenteral route. However, although with lower efficiency, it may be also transmitted by sexual intercourses and by the mother-to-child route. Epidemiological evidence shows that a wave of infection occurred in the 1945-65 period (baby boomers) in western countries. After acute infection, as many as 50-85% of the patients fail to clear the virus resulting in chronic liver infection and/or disease. It is estimated that, on a global scale, about 170 million people are chronically infected with HCV, leading to about 350.000 deaths yearly. Among western countries southern Europe, and particularly Italy, is among the most affected areas. The impact on the public health systems is noteworthy, with high number of hospitalizations due to chronic liver disease, cirrhosis or hepatocellular carcinoma. While waiting for a safe and effective vaccine to be made available, new promising direct-acting antiviral (DAA) drugs offer a better therapeutic scenario than in the past even for the poor responder genotypes 1 and 4, provided that effective screening and care is offered. However, the long and aspecific prodromic period before clinical symptoms develop is a major obstacle to early detection and treatment. Effective screening strategies may target at-risk groups or age specific groups, as recently recommended by the CDC.

Hepatitis C infection in childhood

Hepatitis C infection in children has a different course than in adults, with higher rates of spontaneous clearance. Prenatal (vertical) transmission is the most common route of transmission in childhood. Only a high maternal viral load and HIV co-infection have been proven to increase the risk of infection in the offspring. There is thus no evidence to recommend abstinence from breastfeeding, or elective C-section to prevent transmission. Standard interferon, pegylated interferon and ribavirin are the only approved therapies in children. Severe liver disease is extremely rare in childhood, and described mainly in patients contaminated through blood transfusion.