Final answer:
Syphilis is a bacterial infection passed through contact with sores on the genitals, anus, rectum, or mouth that can cause long-term complications and death if left untreated.
Step-by-step explanation:
The bacterial infection passed from person to person through contact with sores on the genitals, anus, rectum, or mouth that can cause long-term complications and/or death if not adequately treated is Syphilis.