Which biological agent is classified by the CDC as a Category 'B' risk?

Which biological agent is classified by the CDC as a Category 'B' risk?

• A. Variola
• B. Brucella
• C. Yersinia
• D. Bacillus

Answer: (B)

Category B includes organisms that are moderately easy to disseminate and cause moderate illness with low mortality. Brucella fits this profile: it’s a zoonotic bacterium that can be transmitted to people through inhalation or handling infected animals or products, causing brucellosis which typically presents as fever and flu-like symptoms and can become chronic, but has a relatively low risk of death with appropriate treatment. It’s considered a preparedness concern because it can be aerosolized and spread in certain settings, yet it’s not as deadly as the highest-risk agents. In contrast, the other options refer to agents known for high mortality and widespread impact, which are placed in the highest risk category.

Category B includes organisms that are moderately easy to disseminate and cause moderate illness with low mortality. Brucella fits this profile: it’s a zoonotic bacterium that can be transmitted to people through inhalation or handling infected animals or products, causing brucellosis which typically presents as fever and flu-like symptoms and can become chronic, but has a relatively low risk of death with appropriate treatment. It’s considered a preparedness concern because it can be aerosolized and spread in certain settings, yet it’s not as deadly as the highest-risk agents. In contrast, the other options refer to agents known for high mortality and widespread impact, which are placed in the highest risk category.