What term best describes an outbreak affecting a larger geographic area than expected?

The term that best describes an outbreak affecting a larger geographic area than expected is "epidemic." This term is commonly used in public health to refer to a situation where there is an increase in the number of cases of a disease beyond what is normally expected in a specific area or population. An epidemic can occur in a localized area, but it signifies a sudden and rapid increase in the disease incidence that can have serious public health implications.

Understanding the context of the term is important. For example, "endemic" refers to diseases that are consistently present within a certain geographic area or population, at a steady state, without any unusual increases. "Pandemic," on the other hand, describes an epidemic that has spread across multiple countries or continents, affecting a larger global population. "Sporadic" pertains to occasional cases of the disease that occur irregularly and are not part of a larger outbreak.

So, while an epidemic may indicate a serious outbreak or increase in cases in a specific area, a pandemic extends that concept to a global scale, surpassing the boundaries of local or national outbreaks. Therefore, in the context of the question about a larger geographic area, "epidemic" is the correct choice.