Mother-to-child transmission of hepatitis C virus: evidence for preventable peripartum transmission
ABSTRACT Little information is available about the timing of mother-to-child transmission of hepatitis C virus (HCV), and no interventions to decrease transmission rates have been identified. We examined the effect of risk factors, including mode of delivery, on the vertical transmission rate.
Data from HCV-infected women and their infants from three hospitals in Ireland and from a British Paediatric Surveillance Unit study of infants born to HCV-infected mothers were used to estimate the vertical transmission rate and risk factors for transmission. We used a probabilistic model using methods that simultaneously estimated the time to HCV-antibody loss in uninfected infants and the diagnostic accuracy of PCR tests for HCV RNA.
441 mother-child pairs from the UK (227) and Ireland (214) were included. 50% of uninfected children became HCV-antibody negative by 8 months and 95% by 13 months. The estimated specificity of PCR for HCV RNA was 97% (95% CI 96-99) and was unrelated to age; sensitivity was only 22% (7-46) in the first month but rose sharply to 97% (85-100) thereafter. The vertical transmission rate was 6.7% (4.1-10.2) overall, and 3.8 times higher in HIV coinfected (n=22) than in HIV-negative women after adjustment for other factors (p=0.06). No effect of breastfeeding on transmission was observed, although only 59 women breastfed. However, delivery by elective caesarean section before membrane rupture was associated with a lower transmission risk than vaginal or emergency caesarean-section delivery (odds ratio 0 [0-0.87], p=0.04, after adjustment for other factors).
The low sensitivity of HCV RNA soon after birth and the finding of a lower transmission rate after delivery by elective caesarean section suggest that HCV transmission occurs predominantly around the time of delivery. If the findings on elective caesarean section are confirmed in other studies, the case for antenatal HCV testing should be reconsidered.
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ABSTRACT: Hepatitis C virus (HCV) infection is a major global health issue. Infection by the HCV can cause acute and chronic liver diseases and may lead to cirrhosis, hepatocellular carcinoma or liver failure. The World Health Organization estimates that approximately 3% of the world population have been infected with HCV and the worldwide prevalence is between 1% and 8% in pregnant women and between 0.05% and 5% in children. Following the introduction of blood product screening, vertical transmission becomes the leading cause of childhood HCV infection. The prevalence of pediatric HCV infection varies from 0.05% to 0.36% in developed countries and between 1.8% and 5% in the developing world. All children born to women with anti-HCV antibodies should be checked for HCV infection. Though universal screening is controversial, selective antenatal HCV screening on high-risk populations is highly recommended and should be tested probably. Multiple risk factors were shown to increase the possibility of HCV vertical transmission, including coinfections with human immunodeficiency virus, intravenous drug use and elevated maternal HCV viral load, while breastfeeding and HCV genotypes have been studied to have little impact. At present, no clinical intervention has been clearly studied and proved to reduce the HCV vertical transmission risk. Cesarean section should not be recommended as a procedure to prevent vertical transmission, however, breastfeeding is generally not forbidden. The high prevalence of global HCV infection necessitates renewed efforts in primary prevention, including vaccine development, as well as new approaches to reduce the burden of chronic liver disease. Future researches should focus on the interruption of vertical transmission, developments of HCV vaccine and direct-acting antivirals in infancy and early childhood.
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ABSTRACT: Our objective was to provide a comprehensive review of the current knowledge regarding pregnancy and hepatitis B virus (HBV) or hepatitis C virus (HCV) infection as well as recent efforts to reduce the rate of mother-to-child transmission (MTCT). Maternal infection with either HBV or HCV has been linked to adverse pregnancy and birth outcomes, including MTCT. MTCT for HBV has been reduced to approximately 5% overall in countries including the US that have instituted postpartum neonatal HBV vaccination and immunoprophylaxis with hepatitis B immune globulin. However, the rate of transmission of HBV to newborns is nearly 30% when maternal HBV levels are greater than 200 000 IU ml(-1) (>6 log10 copies ml(-1)). For these patients, new guidelines from the European Association for the Study of the Liver (EASL) and the Asian Pacific Association for the Study of the Liver (APASL) indicate that, in addition to neonatal vaccination and immunoprophylaxis, treating with antiviral agents such as tenofovir disoproxil fumarate or telbivudine during pregnancy beginning at 32 weeks of gestation is safe and effective in preventing MTCT. In contrast to HBV, no therapeutic agents are yet available or recommended to further decrease the risk of MTCT of HCV, which remains 3 to 10%. HCV MTCT can be minimized by avoiding fetal scalp electrodes and birth trauma whenever possible. Young women with HCV should be referred for treatment post delivery, and neonates should be closely followed to rule out infection. New, better-tolerated treatment regimens for HCV are now available, which should improve outcomes for all infected individuals.Journal of Perinatology advance online publication, 18 September 2014; doi:10.1038/jp.2014.167.Journal of perinatology: official journal of the California Perinatal Association 09/2014; DOI:10.1038/jp.2014.167 · 2.35 Impact Factor