Stanimar is staying in the hospital after surgery. He starts to suffer from a fever, diarrhea, and abdominal pain. How did Stanimar most likely contract his nosocomial infection? A urinary catheter was not properly sterilized before it was used. A nurse did not properly disinfect her hands before she inserted the ventilator during surgery. A health-care worker did not disinfect her hands after she helped another patient to the bathroom. The surgical instruments that were used during his surgery were not properly cleaned before his procedure.