Francisella tularensis causes which disease?

• A. Rocky Mountain spotted fever
• B. Tularemia
• C. Lyme disease
• D. Plague

Answer: (B)

Francisella tularensis causes tularemia, a zoonotic infection often acquired from handling wild animals such as rabbits or through vector bites, and can also occur by inhalation leading to a pneumonic form. The organism is a small Gram-negative coccobacillus that can live inside macrophages, contributing to disseminated illness and tender regional lymphadenopathy. Tularemia presents in several forms, most commonly ulceroglandular with a painful skin lesion and nearby swollen lymph nodes, but can also be pneumonic, oculoglandular, or glandular. This distinguishes it from the other listed diseases, which are caused by different pathogens: Rocky Mountain spotted fever by Rickettsia rickettsii, Lyme disease by Borrelia burgdorferi, and plague by Yersinia pestis.