What is anthrax and its most deadly form?

• A. A bacterial infection; pulmonary anthrax most deadly.
• B. A viral infection; skin form is most deadly.
• C. A fungal infection; systemic form.
• D. A bacterial infection; gastrointestinal form most deadly.

Answer: (A)

Anthrax is a bacterial infection caused by Bacillus anthracis, which can form hardy spores. Because it is bacterial, antibiotics can treat it if started early, making timely recognition crucial in emergency response. Anthrax has several forms, including cutaneous (skin), inhalational (pulmonary), and gastrointestinal. The inhalational form is the most deadly because inhaled spores germinate in the lungs and release toxins that trigger rapid, widespread illness, including severe respiratory distress and septic shock. The skin form is the most common and generally far less fatal, while gastrointestinal anthrax can be serious but is less lethal than the inhalational form. Therefore, identifying that it is a bacterial infection and that the inhalational (pulmonary) form is the most deadly reflects the correct reasoning.