Micro 75: Trematodes

This episode examines trematodes, or flukes - leaf-shaped flatworms characterised by complex life cycles involving freshwater snails. Drawing from Murray’s Chapter 75, it explores transmission dynamics, tissue localisation, and chronic disease.Trematodes are hermaphroditic (with the exception of Schistosoma species) and require intermediate hosts. Human infection typically occurs via:* Skin penetration by cercariae (Schistosoma)* Ingestion of contaminated water plants or undercooked fishMajor disease categories include:* Schistosomiasis - blood flukes causing granulomatous inflammation around eggs in liver or bladder* Liver flukes (e.g., Clonorchis, Fasciola) - biliary obstruction and chronic inflammation* Intestinal flukes - gastrointestinal irritationPathology is often driven by immune response to deposited eggs rather than adult worms.Conceptually, trematodes illustrate multi-host ecological dependence. Clinically, freshwater exposure and dietary habits are essential diagnostic clues.Key Takeaways* Trematodes are leaf-shaped flatworms* Freshwater snails are key intermediate hosts* Schistosoma penetrates intact skin* Disease often results from egg-induced granulomas* Chronic infection may cause organ fibrosis This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit drmanaankarray.substack.com/subscribe