Which of the following indicates a sudden large increase in disease cases?

The term that indicates a sudden large increase in disease cases is "epidemic." An epidemic refers to a situation where the number of disease cases in a specific area exceeds what is normally expected based on historical data. This term is used to describe outbreaks that occur when a new infectious agent or a significant increase in existing disease leads to a rapid rise in cases, affecting a larger population than usual within a defined geographic area.

In contrast, "familial" pertains to conditions that are observed within families, often carrying genetic implications, but does not indicate a sudden rise in cases. "Endemic" refers to diseases that are consistently present in a specific geographic area, maintaining a baseline level of occurrence but not necessarily experiencing a sudden increase. "Hereditary" relates to traits or conditions passed down through genes from parents to offspring, without any indication of increased incidence.

Thus, the correct choice highlights a critical concept in epidemiology, emphasizing the importance of recognizing patterns in disease occurrence.