Hepatitis C virus (HCV) infection is a leading cause of liver-related morbidity and mortality. Transmission of HCV is primarily via parenteral blood exposure, and HCV can be transmitted vertically from mother to child. Vertical transmission occurs in 5.8% of infants born to women who are infected only with HCV and in up to twice as many infants born to women who are also infected with human immunodeficiency virus (HIV) or who have high HCV viral loads. There is currently no recommended intervention to prevent transmission of infection from mother to child.
Illicit injection drug use is a risk factor for HCV. Recent increases in injection drug use and increases in incidence of HCV infection among young persons has been observed in the U.S. This raises concern about increases in the number of pregnant women with HCV infection, and in the number of infants who could be exposed to HCV at birth. Data from one large commercial laboratory and birth certificate data were used to investigate trends in HCV detection among women of childbearing age, HCV testing among children aged ≤2 years, and the proportions of infants born to HCV-infected women nationally and in Kentucky, the state with the highest incidence of acute HCV infection during 2011 to 2014.
During 2011 to 2014, Quest commercial laboratory data indicated that national rates of HCV detection among women of childbearing age increased 22%, and HCV testing among children aged ≤2 years increased 14%. Birth certificate data indicated that the proportion of infants born to HCV-infected mothers increased 68%, from 0.19% to 0.32%. During the same time in Kentucky, the HCV detection rate among women of childbearing age increased >200%, HCV testing among children aged ≤2 years increased 151%, and the proportion of infants born to HCV-infected women increased 124%, from 0.71% to 1.59%. During 2011 to 2014, HCV case reporting to the Kentucky Department for Public Health (KDPH) identified 777 pregnant women with HCV antibody positivity; 68% were aged 20–29 years, 28% were aged 30–39 years, 84% were non-Hispanic white, and 38% reported past or current injection drug use. Increases in the rate of HCV detection among women of childbearing age suggest a potential risk for vertical transmission of HCV.
These findings highlight the importance of following current CDC recommendations to identify, counsel, and test persons at risk for HCV infection, including pregnant women, as well as consider developing public health policies for routine HCV testing of pregnant women, and expanding current policies for testing and monitoring children born to HCV-infected women. Expansion of HCV reporting and surveillance requirements will enhance case identification and prevention strategies.
Although acute HCV infection, as defined by the Council of State and Territorial Epidemiologists, is a notifiable condition and reportable to the health department in almost all states, persons with acute HCV infection account for a small fraction of persons with newly diagnosed HCV infection; most new diagnoses are among persons with HCV infection of unknown duration. Because reporting of all cases of HCV infection is not mandated in many states, a substantial proportion of HCV-infected women of childbearing age, including pregnant women, are likely not reported in routine state-based surveillance systems. Commercial laboratory data and birth certificate data provide additional sources of information to supplement HCV surveillance data.
The national increases in HCV detection among women of childbearing age, HCV testing among infants, and the proportion of infants born to HCV-infected mothers suggest increased risk for mother-to-child transmission of HCV. This risk might be higher in certain areas of the United States, as illustrated by the findings in this report for Kentucky, which might be related to increasing illicit injection drug use. KDPH surveillance data for pregnant women are also consistent with demographic patterns of HCV incidence overall in Kentucky and nationally.
The potential for mother-to-child transmission of HCV has prompted some jurisdictions to consider changes in HCV case identification strategies and reporting policies. For example, the Philadelphia Department of Public Health recently demonstrated improved identification of infants born to HCV-infected mothers by cross-matching maternal information (including mother’s name and date of birth) on birth certificates to women in HCV surveillance registries. In 2015, Kentucky mandated reporting of all HCV-infected pregnant women and children through age 60 months, as well as all infants born to all HCV-infected women. Development of national reporting criteria to include a case definition for perinatal HCV infection could standardize reporting across states. Reporting pregnancy status as part of HCV laboratory-based surveillance would also facilitate case identification. Improved surveillance can inform HCV screening and testing recommendations for pregnant women. Furthermore, there is an opportunity to detect HCV infection through routine HCV testing of infants identified as having perinatal exposure to illicit drugs, or neonatal abstinence syndrome, and their mothers; this could enhance HCV case identification as suggested by the large proportion of HCV antibody-positive pregnant women in Kentucky who report injecting illicit drugs.
The CDC recommends HCV testing for persons with a history of injection drug use and others at risk, including persons infected with HIV and persons with recognized exposures (e.g., health care workers after needle sticks or mucosal exposure to HCV-positive blood). It is important that providers assess women of childbearing age, particularly pregnant women, for HCV risk and test accordingly. These findings underscore the importance of providing primary prevention services and following current recommendations to identify persons at risk for HCV infection and test accordingly; doing so among pregnant women would improve early identification of HCV-infected infants and linkage of the mother and infant to care and treatment. Furthermore, identifying HCV-infected women of childbearing age before pregnancy, with linkage to care, treatment, and cure, would avoid HCV infection during pregnancy and prevent mother-to-child transmission. Expanding current and developing new public health policies to increase HCV detection among women of childbearing age (especially pregnant women) and infants should be considered. Several organizations have published guidelines on HCV testing of children, but harmonization is needed to ensure that all women who are pregnant or planning pregnancy and all infants born to HCV-infected women are appropriately tested and linked to care if they are infected.
See the CDC Report
See also Medical Law Perspectives, January 2015 Report: Mothers, Infants, and Obstetrical Injuries: Labor and Delivery Liability Risks
See also Medical Law Perspectives, September 2014 Report: Hepatitis: Provider Malpractice and Patient Injury
See the Medical Law Perspectives October 24, 2014, Blog: Expensive HCV Drug Price Going Up in U.S.; Gilead Offers Cheaper Versions in Developing Nations