Blood fluke is a type of parasitic flatworm that infects the bloodstream and causes a disease called schistosomiasis. This disease is primarily found in tropical and subtropical regions, particularly in areas where access to clean water is limited.

Blood flukes are transmitted through contact with contaminated freshwater, where they infect snails, which in turn release infective larvae into the water. Humans become infected when they come into contact with contaminated water while bathing, washing, or fishing. The larvae penetrate the skin and mature into adult worms in the bloodstream, causing inflammation and damage to internal organs over time.

Symptoms of schistosomiasis can include itchy skin, abdominal pain, diarrhea, and blood in the urine.

Treatment involves using anti-parasitic medication, and efforts to improve access to clean water can help to prevent the spread of the disease.