This document discusses trematode infections, including their classification, life cycles, clinical manifestations, investigations, management, and prevention. It focuses on major human trematode infections caused by blood flukes (Schistosoma spp.), liver flukes (Clonorchis sinensis and Opisthorchis spp.), intestinal flukes (Fasciolopsis buski), and lung flukes (Paragonimus westermani). Symptoms vary depending on the infecting organism but can include dermatitis, abdominal pain, bloody stool, hepatosplenomegaly, cough, and pulmonary symptoms. Diagnosis involves microscopy of stool, urine, or sputum samples, serology to detect antibodies or