Summary Background Antenatal antiviral therapy (AVT) is effective in preventing mother‐to‐child transmission (MTCT) in chronic hepatitis B (CHB); tenofovir disoproxil fumarate (TDF) is the preferred agent. Tenofovir alafenamide (TAF) is a prodrug of tenofovir (TFV) similar to TDF, with improved bone and renal safety. There are no data on TAF breast milk pharmacokinetics and exposure to breastfeeding infants in CHB. Aim To assess the pharmacokinetics of TAF/TFV in breastfeeding women with CHB on TAF monotherapy. Methods Pregnant women with CHB requiring AVT commenced TAF 25 mg daily at third trimester or postpartum. Sample collection occurred while breastfeeding and taking TAF for minimum 4 weeks. Maternal blood, breast milk and infant urine samples were collected. Drug concentrations were measured by LCMS/MS analyses using validated methods. Non‐compartmental analyses were performed to quantify the pharmacokinetic parameters. Results Eight women provided samples. In breast milk and plasma, median TAF half‐life was 0.81 and 0.94 h, respectively, and Cmax 1.69 and 120.5 ng/ml, respectively. Median maternal breast milk to plasma (M/P) ratio of TAF was 0.029; for and TFV it was 2.809. The relative infant dose of TAF was 0.005% of maternal dose, well below safety threshold of 5–10%. TFV was detectable in three out of seven infant urine samples with median steady‐state concentration of 5 ng/ml being 300–2500 times less than reported adult steady‐state urine concentrations in those taking TAF and TDF, respectively. Conclusions In this first pharmacokinetic study of TAF monotherapy in breastfeeding women with CHB, concentrations of TAF and TFV were low in breast milk with negligible infant exposure, supporting the use of TAF to prevent MTCT.

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Case detection remains a major challenge for hepatitis C virus (HCV) elimination. We have previously published results from a pilot of an emergency department (ED) semiautomated screening program, SEARCH; Screening Emergency Admissions at Risk of Chronic HCV. Several refinements to SEARCH have been developed to streamline and reduce cost. All direct costs of HCV testing until direct-acting antiviral (DAA) therapy initiation were calculated. Cost was assessed in 2018 Australian Dollars. A cost analysis of the initial program and refinements are presented. Sensitivity analysis to understand impact of variation in staff time, laboratory test cost, changes in HCV antibody (Ab) prevalence, RNA positivity percentage, and rate of linkage to care was conducted. Impact of refinements (SEARCH (2)) to cost is presented. The total SEARCH pilot, testing 5000 patients was estimated to cost $110,549.52 (range $92,109.79–$129,581.24) comprising of $68,278.67 for HCV Ab testing, $21,568.99 for follow-up and linkage to care of positive patients and $20,701.86 to prepare HCV RNA positive patients for treatment. Internal program refinements resulted in a 25% cost reduction. Following refinements, the cost of HCV antibody screening was $8.46 per test and the total cost per positive HCV Ab, positive HCV RNA, and per treated patient were $611.77, $2,168.64, and $3,566.11, respectively. Our sensitivity analysis indicates costs per HCV case found are modest so long as HCV Ab prevalence was at least 1%. ED screening is an affordable strategy for HCV case detection and elimination.