Trichinella murrelli: pathological features in human muscles at different delays after infection

The authors describe the pathological aspects of muscles of three patients infected with Trichinella murrelli. Biopsies were carried out at various intervals. Six weeks after infection, the muscular larvae were not encapsulated whereas encapsulation was seen 10 weeks after infection. Six years after infection, the larvae were still alive in a nurse cell surrounded by a very thick capsule. Fourteen years after infection, cuticular larvae remnants were seen in degenerating nurse cells. The late encapsulation of Trichinella murrelli in human muscles could explain some clinical differences noticed during the outbreak during which these three patients were infected.