Birthright (Georgia Dept of Public Health, 1951)
This film features a pregnant couple named John and Liza Lloyd. They live with Liza's parents, and John works with his father-in-law raising chickens. One day, John and Liza get in a fight, and John gets drunk and has an affair with a bartender named Nell. Soon after, Liza tells John that she's pregnant, and Nell learns that she has syphilis. The public health nurse encourages Nell to contact the people with whom she recently had sexual relations, but she never learned John's name and consequently had no way of contacting him.