Effect of Muscle Strength by Trichinella spiralis Infection during Chronic Phase.

Introduction:Trichinella spiralis establishes a chronic infection in skeletal muscle by developing nurse cells within muscle fibers. During symbiosis in host, changes in the muscle fibers and inflammation may affect muscle function. Methods: We investigated muscle strength and inflammation in T. spiralis-infected mice during 1 to 48 weeks after infection. Results: Muscle strength decreased compared to that in uninfected control mice during the late infection stage. Additionally, inflammatory related cytokines increased significantly during early stage of infection and then rapidly decreased. In pathological study, nuclear infiltration maintained from the early infection stage to chronic infection stage. Moreover, vacuoles and eosinophil infiltration were observed in infected muscle in chronic stage. Conclusion: These results suggest that infection by T. spiralis significantly affects muscle function was continuously being weakness because vacuoles formation and maintained nucleus and eosinophil infiltration during chronic phase of T. spiralis infection.