Transmission of hepatitis C virus from infected mother to offspring during subsequent pregnancies

CDC Recommendations for Hepatitis C Testing Among Perinatally Exposed Infants and Children - United States, 2023

The elimination of hepatitis C is a national priority (https://www.hhs.gov/sites/default/files/Viral-Hepatitis-National-Strategic-Plan-2021-2025.pdf). During 2010-2021, hepatitis C virus (HCV) acute and chronic infections (hereinafter referred to as HCV infections) increased in the United States, consequences of which include cirrhosis, liver cancer, and death. Rates of acute infections more than tripled among reproductive-aged persons during this time (from 0.8 to 2.5 per 100,000 population among persons aged 20-29 years and from 0.6 to 3.5 among persons aged 30-39 years). Because acute HCV infection can lead to chronic infection, this has resulted in increasing rates of HCV infections during pregnancy. Approximately 6%-7% of perinatally exposed (i.e., exposed during pregnancy or delivery) infants and children will acquire HCV infection. Curative direct-acting antiviral therapy is approved by the Food and Drug Administration for persons aged ≥3 years. However, many perinatally infected children are not tested or linked to care. In 2020, because of continued increases in HCV infections in the United States, CDC released universal screening recommendations for adults, which included recommendations for screening for pregnant persons during each pregnancy (Schillie S, Wester C, Osborne M, Wesolowski L, Ryerson AB. CDC recommendations for hepatitis C screening among adults-United States, 2020. MMWR Recomm Rep 2020;69[No. RR-2]:1-17). This report introduces four new CDC recommendations: 1) HCV testing of all perinatally exposed infants with a nucleic acid test (NAT) for detection of HCV RNA at age 2-6 months; 2) consultation with a health care provider with expertise in pediatric hepatitis C management for all infants and children with detectable HCV RNA; 3) perinatally exposed infants and children with an undetectable HCV RNA result at or after age 2 months do not require further follow-up unless clinically warranted; and 4) a NAT for HCV RNA is recommended for perinatally exposed infants and children aged 7-17 months who previously have not been tested, and a hepatitis C virus antibody (anti-HCV) test followed by a reflex NAT for HCV RNA (when anti-HCV is reactive) is recommended for perinatally exposed children aged ≥18 months who previously have not been tested. Proper identification of perinatally infected children, referral to care, and curative treatment are critical to achieving the goal of hepatitis C elimination.

Estimation of hepatitis C virus infections resulting from vertical transmission in Egypt

Despite having the highest hepatitis C virus (HCV) prevalence in the world, the ongoing level of HCV incidence in Egypt and its drivers are poorly understood. Whereas HCV mother-to-child infection is a well-established transmission route, there are no estimates of HCV infections resulting from vertical transmission for any country, including Egypt. The aim of this study was to estimate the absolute number of new HCV infections resulting from vertical transmission in Egypt. We developed a conceptual framework of HCV vertical transmission, expressed in terms of a mathematical model and based on maternal HCV antibody and viremia. The mathematical model estimated the number of HCV vertical infections nationally and for six subnational areas. Applying two vertical transmission risk estimates to the 2008 Egyptian birth cohort, we estimated that between 3,080 and 5,167 HCV infections resulted from vertical transmission among children born in 2008. HCV vertical transmission may account for half of incident cases in the <5-year age group. Disproportionately higher proportions of vertical infections were estimated in Lower Rural and Upper Rural subnational areas. This geographical clustering was a result of higher-area-level HCV prevalence among women and higher fertility rates.

CONCLUSION

Vertical transmission is one of the primary HCV infection routes among children<5 years in Egypt. The absolute number of vertical transmissions and the young age at infection highlight a public health concern. These findings also emphasize the need to quantify the relative contributions of other transmission routes to HCV incidence in Egypt.

Vertical transmission of hepatitis C virus: systematic review and meta-analysis

Updated pooled estimates of vertical hepatitis C (HCV) infection risk to children of HCV RNA–positive mothers ranges between 5.8% and 10.8%, depending on maternal HIV coinfection. Additional risk factors need to be captured and reported by future studies.

Background. We conducted a systematic review of estimates of hepatitis C virus (HCV) vertical transmission risk to update current estimates published more than a decade ago.

Methods. PubMed and Embase were searched and 109 articles were included. Pooled estimates of risk were generated for children born to HCV antibody–positive and viremic women, aged ≥18 months, separately by maternal human immunodeficiency virus (HIV) coinfection.

Results. Meta-analysis of the risk of vertical HCV infection to children of HCV antibody–positive and RNA-positive women was 5.8% (95% confidence interval [CI], 4.2%–7.8%) for children of HIV-negative women and 10.8% (95% CI, 7.6%–15.2%) for children of HIV-positive women. The adjusted meta-regression model explained 51% of the between-study variation in the 25 included risk estimates. Maternal HIV coinfection was the most important determinant of vertical transmission risk (adjusted odds ratio, 2.56 [95% CI, 1.50–4.43]). Additional methodological (follow-up rate and definition of infection in children) and risk factors independently predicted HCV infection and need to be captured and reported by future studies of vertical transmission. Studies assessing the contribution of nonvertical exposures in early childhood to HCV prevalence among children at risk of vertical transmission are needed.

Conclusions. More than 1 in every 20 children delivered by HCV chronically infected women are infected, highlighting that vertical transmission likely constitutes the primary transmission route among children. These updated estimates are a basis for decision making in prioritization of research into risk-reducing measures, and inform case management in clinical settings, especially for HIV-positive women in reproductive age.

Hepatitis C virus infection of human cytotrophoblasts cultured in vitro

Hepatitis C virus (HCV) infection in the uterus is a significant path of vertical HCV transmission. Some studies consider vertical HCV transmission in the uterus as the result of maternal blood leakage into infant blood, whereas others theorize that HCV is transmitted by the mother to the infant through cells constituting the placenta barrier. Although trophoblasts play an important role in the placenta barrier, no definitive evidence has been presented to prove that cytotrophoblasts can be infected with HCV. The current study investigated whether or not these can be infected with HCV by conducting an experiment, in which cultured human cytotrophoblasts were infected with HCV in vitro. The results were analyzed using reverse transcription polymerase chain reaction (RT-PCR), ultrastructural characteristic changes under an electron microscope, and immunoelectron microscopy. HCV RNA in the supernatant of the cultured medium of the infected group was intermittently detected during the 16-day incubation period using RT-PCR. Under an electron microscope, the ultrastructures of infected human cytotrophoblasts were markedly different from normal cells, demonstrating lysosomal hyperplasia, rough endoplasmic reticulum, decreased lipid droplets, presence of vacuoles, and the appearance of HCV-like particles. Using immunoelectron microscopy, HCV-like particles conjoined with golden granules were also observed. Based on the data, the current study concludes that HCV infects a human cytotrophoblast cultured in vitro; moreover, its ultrastructure changes dramatically upon infection.

NASPGHAN practice guidelines: Diagnosis and management of hepatitis C infection in infants, children, and adolescents

Hepatitis C virus (HCV) is an RNA virus that affects >180 million individuals worldwide with a high propensity for chronic infection. Children with HCV infection differ from adults in several ways including some modes of transmission, rates of clearance, progression of fibrosis, and the duration of potential chronic infection when acquired at birth. Since the discovery of HCV in 1989, there have been significant advances in the understanding of the virology and natural history of chronic HCV infection in children. In addition, there are now several treatment options for children with chronic hepatitis C infection and many new therapies on the horizon. As a consequence, the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition brought together experts in pediatric hepatology to review the available data in children and provide clinicians with approaches to the diagnosis, management, and prevention of HCV infection in children and adolescents. The guideline details the epidemiology and natural history of HCV infection in children, the diagnostic workup, monitoring and treatment of disease, and provides an update on future treatment options and areas of research.

Chronic hepatitis C virus infection in children and adolescents: Epidemiology, natural history, and assessment of the safety and efficacy of combination therapy

Hepatitis C virus (HCV) is the most common cause of chronic liver disease of infectious etiology in children. Most of the children infected with HCV are asymptomatic, and only a few of them develop signs and symptoms of end-stage liver disease early in life. It is not possible to predict either in which patients HCV infection will have a bad outcome or the critical time in early adulthood when disease progression will accelerate. The experiences with therapy in children with chronic hepatitis C are based on earlier and continuing data from adult trials. The currently recommended treatment for chronic HCV infection in adults is the combination of peginterferon-á and ribavirin. The choice of this regimen is based on the results of randomized clinical trials that demonstrated the superiority of this combination treatment over standard interferon-á and ribavirin. Recently, results of pivotal, multicenter, interventional open-label studies on combined treatment with peginterferon-á and ribavirin in children have been published, and the US Food and Drug Administration and the European Medicines Agency have approved the combination therapy in those older than 3 years. The aim of this review is to evaluate critically the available data regarding the safety and efficacy of combination treatment with peginterferon-á and ribavirin in children.

Perinatal transmission of hepatitis C virus infection

In industrialized countries, hepatitis C virus (HCV) is the most common cause of chronic liver disease in children. Perinatal transmission is the leading cause of infection. Perinatal transmission is confined almost always to women with detectable HCV ribonucleic acid (RNA) in the peripheral blood by the polymerase chain reaction but all children born to women with anti-HCV antibodies should be tested for HCV. Some but not all studies found that a high concentration of serum HCV RNA is associated with a higher risk of transmission. Maternal peripheral blood mononuclear cell infection by HCV, membrane rupture of longer than 6 hr before delivery, and procedures exposing the infant to maternal blood infected with HCV during vaginal delivery are associated with an increased risk of transmission. Maternal coinfection with HCV and human immunodeficiency virus, maternal history of intravenous drug use and of HCV infection of the sexual partner of the mother predict the risk of perinatal transmission and are dependent on the peripheral blood mononuclear cell infection by HCV. Delivery by Cesarean section is not recommended in pregnant women infected with HCV. Infected mothers can breast feed safely their infants if the nipples are not damaged. A previous delivery of a child infected perinatally with HCV does not increase the risk of transmission in subsequent pregnancies. Immunogenetic factors and HCV genotypes are not related to HCV perinatal transmission. Despite an increased understanding of the risk factors involved in perinatal transmission of HCV, to date little is known about the transmission mechanisms and timing.

Hepatitis C virus infection

The prevalence of chronic hepatitis C infection in the general paediatric population varies between 0.1 and 15% around the world, with the highest numbers noted in endemic areas of Africa. The risk of viral transmission from an infected mother to her child is approximately 5% and there are currently no effective preventative measures to lower it. All children born to infected mothers should be tested for hepatitis C. The progression to liver damage in infected children is slow. However, in the perspective of 15-20 years of infection or in the presence of other risk factors, such as concomitant chronic disease, a progression to more severe liver damage can be seen. Thus, the use of antiviral treatment may be of importance. Treatment combinations of interferon and ribavirin seem to be at least as effective in children as in adults. However, the negative effect on growth of interferon requires specific attention by paediatricians.

Hepatitis C virus-specific reactivity of CD4+-lymphocytes in children born from HCV-infected women

BACKGROUND/AIMS

T-lymphocyte reactivity against viral antigens may represent the only immunological marker of host contact with a virus. Aim of the present study was to investigate whether vertical exposure to hepatitis C virus (HCV) could activate HCV-specific T-cell responses that may represent a biomarker of previous contact with the virus, and possibly contribute to the low rate of vertical HCV transmission.

METHODS

We studied 28 children born from chronically HCV-infected mothers. HCV-specific activation and proliferation of CD4+-lymphocytes and cytokine production were evaluated in cultures of peripheral blood mononuclear cells (PBMCs) stimulated in vitro with HCV-peptides.

RESULTS

HCV-specific CD4+-cell reactivity was observed in 20 out of the 28 children (71%). The proliferation of HCV-specific CD4+-cells was more frequent and vigorous in children than in their mothers. In children, but not in the mothers, activation of CD4+-cells upon stimulation with HCV-peptides was directly correlated with proliferation. Early upon stimulation with HCV-peptides, lymphocytes from children produced lower levels of IL-10 than lymphocytes from the mothers.

CONCLUSIONS

Vertical exposure to HCV induces the development of viral-specific CD4+-cell-mediated immune responses, possibly endowed with protective function against infection, which may contribute to the low rate of vertical HCV transmission.

Clinical implications of mother-to-child transmission of HCV

Testing for vertical transmission of hepatitis C virus (HCV) infection in infants and children will enable early identification of the majority of uninfected HCV-exposed infants and children, and will provide significant emotional relief for the parents.

CONCLUSION

The small percentage of infected children should be offered enrollment in well-designed clinical trials of optimal medical management for prevention of the predicted long-term outcomes of chronic HCV infection: chronic hepatitis, cirrhosis and hepatocellular carcinoma.

Guidelines for the screening and follow-up of infants born to anti-HCV positive mothers

Hepatitis C virus infection in infancy largely depends on vertical transmission. The transfer of hepatitis C virus from mother to child is almost invariably restricted to children whose mother is viremic, and the rate of transmission seems to be influenced by maternal virus load, although, in the single patient, the levels of viremia cannot be used as predictors of pediatric infection. In fact, the flow-chart for screening children at risk for vertically transmitted hepatitis C virus infection takes into account maternal viremia. In children born to anti-hepatitis C virus antibody positive, hepatitis C virus-RNA negative mothers, alanine aminotransferase and anti-hepatitis C virus should be investigated at 18-24 months of life. If alanine aminotransferase values are normal and anti-hepatitis C virus is undetectable, follow-up should be interrupted. In children born to hepatitis C virus-RNA positive mothers, alanine aminotransferase and hepatitis C virus RNA should be investigated at 3 months of age: (1) hepatitis C virus-RNA positive children should be considered infected if viremia is confirmed by a second assay performed within the 12th month; (2) hepatitis C virus-RNA negative children with abnormal alanine aminotransferase should be tested again for viremia at 6-12 months, and for anti-hepatitis C virus at 18 months; (3) hepatitis C virus-RNA negative children with normal alanine aminotransferase should be tested for anti-hepatitis C virus and alanine aminotransferase at 18-24 months, and should be considered non-infected if alanine aminotransferase is normal and anti-hepatitis C virus undetectable; (4) anti-hepatitis C virus seropositivity beyond the 18th month in a never-viremic child with normal alanine aminotransferase is likely consistent with past hepatitis C virus infection.

Ultrastructure characteristics of HCV infected human trophoblast cells in culture

AIM: To investigate whether the cultured trophoblastic cells can be infected with hepatitis C virus (HCV) and observe the ultrastructural features of infected cells.

METHODS: Human placentae were digested with trypsin and then centrifuged with percoll density gradient to obtain trophoblastic cells, and then incubated in HCV positive serum. The HCV RNA in HCV infected syncytiotroblasts was quantitated with RT-PCR. Ultrastructural characteristics of infected syncytiotroblasts were observed with transmission electron microscope.

RESULTS: HCV RNA was detected in supernatant of the cultured medium during 40 day periods of incubation. The antibody of HCV NS5 was observed around the nucleus with confocal microscope. The Ultrastructure of infected throphotoblast cells differed obviously from that of normal cells, and manifested with hyperplasia of lysosomes and rough endoplasmic, appearance of vacuoles and virus-like particles, and decreased lipid droplets.

CONCLUSION: Trophoblastic cells could be infected by HCV, and the cellular ultrastructure changed dramatically following infection of HCV.

Chronic hepatitis C virus infection in childhood: clinical patterns and evolution in 224 white children

The characteristics and evolution of hepatitis C virus (HCV) infection were retrospectively investigated in a study of 224 HCV RNA-seropositive white children who were consecutively recruited at 7 European centers in 1980-1998. At presentation, all patients were positive for antibodies to hepatitis C virus, 87% were asymptomatic, and 48% had alanine aminotransferase (ALT) levels that were < or =2 times the upper limit of the range considered to be normal. Of 200 children followed for 1-17.5 years (mean follow-up +/- standard deviation [SD], 6.2+/-4.7 years), only 12 (6%) achieved sustained viremia clearance and normalization of the ALT level. In 92 revised liver biopsy specimen analyses, the mean fibrosis score (+/-SD) was 1.5+/-1.3 for children <15 years of age and 2.3+/-1.2 for children > or =15 years of age (range, 0-6 years; P<.01). Pediatric HCV infection is usually mild, but few patients, especially those who are perinatally infected, clear viremia in the medium-term follow-up. Conversely, the higher rates of fibrosis observed in older patients suggest the possibility of an insidious progression of HCV-associated liver disease.

[Transmission of hepatitis C virus in pregnant women]

BACKGROUND AND OBJECTIVE

Our goal was to determine the prevalence of hepatitis C virus infection in pregnant women from Asturias as well as the vertical transmission rate.

PATIENTS AND METHOD

This was a prospective study of consecutive pregnant women from the 5th Health Area of Principado de Asturias (Northern Spain). We determined the prevalence of hepatitis C virus infection in the first trimester of pregnancy and the rate of mother-to-child transmission. Time period was August 1997-December 1998. Children were followed from birth to 18-24 months of age. Methods included anti-HVC, PCR-RNA-HVC, genotype and viral load at delivery of all positive women; and anti-HVC and PCR-RNA-HVC at birth, 3, 6, 12 and 18 months of age of their children.

RESULTS

Out of 2442 consecutive pregnant women, 30 were anti-HVC positive (prevalence: 1.23% of pregnancies and 1.20% of women); 24 of them were PCR-RNA-HVC positive. There were 30 anti-HVC positive children. All but one lost their antibodies (vertical transmission rate 3.3%).

CONCLUSIONS

The prevalence of hepatitis C virus infection was 1.20% of women from our Health Area. Vertical transmission rate was 3.3% among HVC infected, non-selected mothers.

Maternal-infant transmission of hepatitis C virus infection

Mother-to-infant transmission of hepatitis C virus (HCV) is comparatively uncommon. The prevalence of antibody to HCV (anti-HCV) in pregnant women is 0.1% to 2.4%, although in some endemic areas it is much higher. The proportion of women with anti-HCV who have active infection with viremia is 60% to 70%. Transmission of HCV occurs only when serum HCV RNA is detectable and may be related to higher levels (above 10(6) copies per mL). The rate of mother-to-infant transmission is 4% to 7% per pregnancy in women with HCV viremia. Co-infection with human immunodeficiency virus (HIV) increases the rate of transmission 4 to 5 fold. The actual time and mode of transmission are not known. Elective Cesarean section is not recommended for women with chronic HCV infection alone. The role of treatment to prevent transmission is limited by the fetal toxicity of currently available medications for hepatitis C. Breast feeding poses no important risk of HCV transmission if nipples are not traumatized and maternal hepatitis C is quiescent. Pregnant women at high risk for HCV infection should be screened for anti-HCV, and HCV RNA testing should be performed if anti-HCV is positive. Infants of women with hepatitis C should be tested for HCV RNA on two occasions, between the ages of 2 and 6 months and again at 18 to 24 months, along with serum anti-HCV. The natural history of mother-to-infant hepatitis C remains uncertain, especially the course in the first year of life when some infants appear to have spontaneous resolution.

Maternal-infant transmission of hepatitis C virus infection

Mother-to-infant transmission of hepatitis C virus (HCV) is comparatively uncommon. The prevalence of antibody to HCV (anti-HCV) in pregnant women is 0.1% to 2.4%, although in some endemic areas it is much higher. The proportion of women with anti-HCV who have active infection with viremia is 60% to 70%. Transmission of HCV occurs only when serum HCV RNA is detectable and may be related to higher levels (above 10(6) copies per mL). The rate of mother-to-infant transmission is 4% to 7% per pregnancy in women with HCV viremia. Co-infection with human immunodeficiency virus (HIV) increases the rate of transmission 4 to 5 fold. The actual time and mode of transmission are not known. Elective Cesarean section is not recommended for women with chronic HCV infection alone. The role of treatment to prevent transmission is limited by the fetal toxicity of currently available medications for hepatitis C. Breast feeding poses no important risk of HCV transmission if nipples are not traumatized and maternal hepatitis C is quiescent. Pregnant women at high risk for HCV infection should be screened for anti-HCV, and HCV RNA testing should be performed if anti-HCV is positive. Infants of women with hepatitis C should be tested for HCV RNA on two occasions, between the ages of 2 and 6 months and again at 18 to 24 months, along with serum anti-HCV. The natural history of mother-to-infant hepatitis C remains uncertain, especially the course in the first year of life when some infants appear to have spontaneous resolution.

Hepatitis C-Z: recent advances

In this review, recently identified hepatitis viruses (hepatitis C, hepatitis D, hepatitis E, hepatitis F, hepatitis G, transfusion transmissible virus) are described, and the implications for paediatric liver disease discussed.

Clinical course of pregnant women with chronic hepatitis C virus infection and risk of mother-to-child hepatitis C virus transmission

As far as concerns chronic hepatitis C virus infection in pregnant women, different points remain to be elucidated, such as the clinical course, the rate of mother-to-child hepatitis C virus transmission and, in particular, its route and the possible risk factors. This review aimed to analyse current data on the prevalence of chronic hepatitis C virus infection in pregnant women and its relationship with risk factors, the rate of mother-to-child hepatitis C virus transmission and the factors possibly involved, particularly the maternal hepatitis C virus viral load and the human immunodeficiency virus coinfection, and the type of delivery and feeding. Finally, the appropriate timing for HCV-RNA testing in newborns has been reviewed.