Undeclared pre-exposure or post-exposure prophylaxis (PrEP/PEP) use among syphilis-positive blood donors, England, 2020 to 2021 Maddox, Victoria and Reynolds, Claire and Amara, Alieu and Else, Laura and Brailsford, Susan R and Khoo, Saye and Harvala, Heli, Eurosurveillance, 28, 2300135 (2023), https://doi.org/10.2807/1560-7917.ES.2023.28.11.2300135