Jan Barbo likely got hepatitis C from a blood transfusion. Almost 50 years ago, she suffered an ectopic pregnancy when a fertilized egg attached itself in her fallopian tube instead of her uterus. Barbo needed emergency surgery and two pints of blood after her fallopian tube, unable to accommodate the growing embryo, ruptured.“The nation’s blood supply wasn’t screened for hepatitis C until 1992, when a highly sensitive test to detect...