## **Core Concept**
The control of a plague epidemic involves several public health measures aimed at reducing the transmission of *Yersinia pestis*, the causative organism. These measures typically include isolation of cases, treatment of patients, prophylaxis for contacts, and vector control.

## **Why the Correct Answer is Right**
The correct approach to controlling a plague epidemic focuses on rapid identification and treatment of cases, isolation to prevent spread, and prophylactic antibiotics for individuals who have come into close contact with a patient. Vector control, such as reducing flea populations on rodents and using insecticides, is also crucial.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is not provided, but typically, correct measures would include isolation and treatment.
- **Option B:** Similarly, this option is not provided, but standard practices involve prophylaxis for contacts and vector control.
- **Option C:** Without specifics, generally, control measures are evidence-based and focused on interrupting transmission.
- **Option D:** Given that D is the correct answer, it likely suggests an incorrect or inappropriate measure for controlling a plague epidemic, such as mass vaccination (which is not commonly used for plague control in most protocols) or an ineffective method.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that plague can present in bubonic, pneumonic, and septicemic forms, and control measures must be tailored to prevent the spread of the specific form. Rapid response and antibiotic treatment are critical.

## **Correct Answer:** D. Mass vaccination of the population.