Which statement best captures the overall disease mechanism of schistosomiasis as described?

Which statement best captures the overall disease mechanism of schistosomiasis as described?

• A. The parasites cause skin penetration, circulation entry, organ-specific migration, and tissue damage through granuloma formation
• B. The parasites cause immediate systemic infection without organ involvement
• C. The disease is caused by bacteria rather than parasites
• D. The disease affects only the skin and never internal organs

Answer: (A)

Schistosomiasis pathology comes from how the host reacts to the eggs laid by the adult worms after the parasites enter through the skin and travel in the bloodstream to specific organs. The cercariae penetrate the skin, circulate to the liver–mesenteric or pelvic venous systems, and deposit eggs in tissues. The immune response to these eggs forms granulomas, which drive inflammation and fibrosis that damage the liver, intestines, bladder, and other organs. This combination of skin entry, systemic migration to target organs, and tissue injury caused by granulomatous inflammation best captures the disease mechanism. It is not a simple bacterial infection, and it does involve internal organs rather than affecting only the skin.

Schistosomiasis pathology comes from how the host reacts to the eggs laid by the adult worms after the parasites enter through the skin and travel in the bloodstream to specific organs. The cercariae penetrate the skin, circulate to the liver–mesenteric or pelvic venous systems, and deposit eggs in tissues. The immune response to these eggs forms granulomas, which drive inflammation and fibrosis that damage the liver, intestines, bladder, and other organs. This combination of skin entry, systemic migration to target organs, and tissue injury caused by granulomatous inflammation best captures the disease mechanism. It is not a simple bacterial infection, and it does involve internal organs rather than affecting only the skin.