What is the name of the contagious, nonsexually transmitted disease seen in tropical regions caused by Treponema pallidum subspecies pertenue that is characterized by granulomatous lesions?

• A. Yaws
• B. Leprosy
• C. Buruli ulcer
• D. Cutaneous anthrax

Answer: (A)

This question centers on an endemic, nonvenereal treponemal infection found in tropical areas that produces granulomatous skin lesions. Treponema pallidum subspecies pertenue causes yaws, a contagious disease spread by direct skin contact with an active lesion. The telltale lesions are granulomatous and can start as a papule that evolves into a nodular, ulcerative form, often on the limbs, especially in children. This distinguishes it from sexually transmitted treponemal infections like syphilis, which are venereal and not tied to tropical, endemic yaws presentations. Other options involve entirely different pathogens and clinical pictures: leprosy shows hypopigmented, anesthetic patches with nerve involvement; Buruli ulcer presents as painless undermined ulcers due to Mycobacterium ulcerans; cutaneous anthrax produces a characteristic painless black eschar. Therefore, the disease described is yaws.