Hepatitis C, Perinatal Infection
2018 Case Definition

Background

Screening recommendations and interpretation of perinatal hepatitis C virus (HCV) laboratory test results for infants born to HCV-infected mothers differ from those for adolescents and adults (1, 2). There has been a reported increase of HCV infection among women of childbearing age in numerous jurisdictions in the United States (3-5), and there would be an expected rise in perinatal transmission as a result. While there are no measures currently recommended for prevention of HCV transmission by pregnant women to their infants, HCV in pediatric populations can lead to significant illness (6) and it is important for those children to be appropriately assessed and in clinical care for HCV infection. Available curative HCV therapies are not currently recommended for pediatric patients under the age of 12, but that may change as data become available on the use of recently approved medications in younger pediatric populations.

There is no one standard HCV screening recommendation for infants born to HCV infected mothers. Available guidelines consistently recommend against antibody testing for children under 18 months of age due to transient maternal HCV antibody that may not reflect actual infection status of the child. However, there are multiple recommended timelines for HCV ribonucleic acid (RNA) screening of infants born to HCV-infected mothers. These include not testing until at least 1-2 months of age and, in some cases, recommending repeat serial testing of infants if an infant tests positive on one test, if done before 12 months of age. There is concern that testing outside of recommended parameters may identify transient HCV RNA in infants that may spontaneously clear the infection following perinatal exposure. Inappropriate testing and loss of follow-up of infants born to HCV-infected mothers has been reported (7).

There is currently no recommendation for universal HCV screening among pregnant women. Testing is only recommended for women of childbearing age if they are known to be at-risk for HCV infection, regardless of pregnancy status.

Clinical Criteria

Perinatal hepatitis C in pediatric patients may range from asymptomatic to fulminant hepatitis.

Laboratory Criteria For Diagnosis

• HCV RNA positive test results for infants between 2 to 36 months of age; OR
• HCV genotype test results for infants between 2 to 36 months of age or greater; OR
• HCV antigen test results for infants between 2 to 36 months of age or greater.

Epidemiologic Linkage

Maternal infection with HCV of any duration, if known. Not known to have been exposed to HCV via a mechanism other than perinatal (e.g. not acquired via healthcare).

Criteria to Distinguish a New Case from an Existing Case

Test results prior to 2 months of age should not be used for classification. Test results after 36 months of age should be reported under the 2015 Acute and Chronic HCV Infection case classification and not as perinatal HCV infection. Cases in the specified age range that are known to have been exposed to HCV via healthcare and not perinatally should be reported under the 2015 position statement. Event date should be based on earliest relevant laboratory test date within the 2-36 month window.

Confirmed

Infant who has a positive test for HCV RNA nucleic acid amplification test (NAAT), HCV antigen, or detectable HCV genotype at ≥2 months and ≤36 months of age and is not known to have been exposed to HCV via a mechanism other than perinatal.