Which of the following is NOT on the CDC list of potential Category B bioterrorism agents?

• A. Burkholderia mallei
• B. Coxiella burnetii
• C. E. coli 0157:H7
• D. Francisella tularensis

Answer: (D)

Understanding how the CDC prioritizes bioterrorism threats helps explain this. Tularemia, caused by Francisella tularensis, is classified as a Category A agent, the highest priority group. Category A agents are those considered to pose the greatest risk due to their potential for easy dissemination and high mortality. In contrast, Category B includes agents that are more readily disseminated and cause moderate morbidity; examples commonly listed there are Burkholderia mallei and Coxiella burnetii. Because Francisella tularensis is in Category A, it does not appear on the Category B list.