Hepatitis C Virus Testing in Perinatally Exposed Children.

Importance: Despite rising hepatitis C virus (HCV) incidence in pregnant people, studies demonstrate that fewer than 50% of perinatally exposed infants receive HCV testing. Few studies report treatment of infected infants or factors affecting testing. Objective: To identify birthing parent and child factors associated with appropriate HCV testing for perinatally exposed infants and characterize HCV care for children with HCV. Design, Setting, and Participants: This cohort study included records on testing, care, and treatment for Massachusetts children perinatally exposed to HCV between 2014 and 2021 from a statewide health database linking statewide vital statistics, infectious disease surveillance data, substance use treatment, and insurance claims data. Data were analyzed from April 2023 to June 2025. Exposure: Linkage to a birthing parent with a confirmed (RNA positive) or probable (antibody positive; no RNA testing) HCV case reported to the Massachusetts Department of Public Health. Main Outcomes and Measures: Guideline-appropriate HCV antibody or RNA testing and HCV treatment were the main outcomes. Multivariable logistic regressions were used to analyze factors associated with guideline-concordant HCV testing. Results: Between 2014 and 2021, 4548 children were born (between 0.7% and 1.3% of yearly births) in Massachusetts to 3693 birthing parents with probable or confirmed HCV; among 4103 children who were aged 2 years or older by study end (2103 male [51.3%]; 289 Black non-Hispanic [7.0%], 575 Hispanic [14.0%], 3069 White non-Hispanic [74.8%]; 3185 [77.6%] with public insurance at delivery), 41.9% completed appropriate perinatal HCV exposure testing. HCV was diagnosed in 40 (2.5%) of those tested; between 1 and 10 of 38 treatment-eligible children were treated by 2022 (number suppressed due to value between 1 and 10). Appropriate testing rates decreased over time and were lowest for those born in 2020 (32.3%; 95% CI, 28.9%-35.7%). A medical claim for the birthing parent's HCV within 30 days of delivery (adjusted odds ratio [aOR], 5.40; 95% CI, 4.19-6.96), medication for opioid use disorder treatment during pregnancy (aOR, 1.29; 95% CI, 1.09-1.51), and factors correlated with HCV risk were associated with significantly higher odds of appropriate testing; non-Hispanic Black race (aOR, 0.65; 95% CI, 0.45-0.94) and private insurance (aOR, 0.76; 95% CI, 0.62-0.93) were associated with lower appropriate testing odds. Conclusions and Relevance: In this cohort study of perinatally exposed infants, HCV testing decreased over time, and few were treated. Communication and recognition of the birthing parent's HCV risk or diagnosis were associated with greater odds of testing completion; these modifiable factors could be addressed to improve equitable HCV testing and care.