Healthcare professionals should test liver recipi- ents for hepatitis B virus (HBV) given the slight risk for unexpected donor-derived HBV infection, according to research published in Morbidity and Mortality Weekly Report. Investigators analyzed laboratory and medical records for 20 reports (2014 to 2019) of HBV infection among re- cipients of livers from donors who had no evi- dence of past or current HBV infection. They found that 14 of the 20 new HBV infections were detected during 2019 alone. Infections were detected 5 to 116 weeks after transplantation (median, 38 weeks). Of the 14 donors, 13 were hepatitis C virus (HCV)-seropositive and within the year preceding death, had a history of injec- tion drug use, a positive toxicology result, or both. “Because injection drug use is the most common- ly reported risk factor for hepatitis C, providers caring for recipients of organs from donors who are HCV-seropositive or recently injected drugs should maintain awareness of infectious compli- cations of injection drug use and monitor recip- ients accordingly,” the study authors wrote. “In addition to testing for HBV DNA at 4 to 6 weeks after transplantation, clinicians caring for liver transplant recipients should consider testing for HBV DNA 1 year after transplantation or at any time if signs and symptoms of viral hepatitis de- velop, even if previous tests were negative.”