Which of the following is a Category A bioterrorism agent?

• A. Lassa virus
• B. Nipah virus
• C. Ricin toxin
• D. Burkholderia pseudomallei

Answer: (A)

Category A agents are the highest priority because they can be spread easily and cause high mortality, triggering widespread fear and a need for an intense public health response. Lassa virus fits this category because it causes Lassa fever, an arenavirus hemorrhagic fever with potential for human-to-human transmission and outbreaks that can lead to significant mortality. This combination of ease of spread and severe disease places it among the top Category A bioterrorism agents.

The other options don’t sit in Category A: Nipah virus is highly dangerous but is not listed as Category A in standard public health classifications; ricin toxin is a toxin categorized as Category B due to its risk profile and dissemination potential being different from Category A viral threats; Burkholderia pseudomallei is a highly virulent organism and a select agent but is not included in the Category A list.