Murine Model of Neuroschistosomiasis Mansoni: Clinical, Histological and Magnetic Resonance Imaging Studies

Abstract

The schistosomiasis mansoni infection is responsible for 3.6% of the worldwide estimated causes of death and the central nervous system can be affected. In humans, the eggs of this helminth have been found in the leptomeninges, cerebral cortex, basal ganglia, choroid plexus, cerebellum and spinal cord. Neurological manifestations, histhology and magnetic resonance imaging of neuroschistosomiasis mansoni in humans serve as our chief reference points for the examination of the experimental infections in murine model. In this study, experimental infection of S. mansoni cercariae in mice aims to demonstrate the presence of granulomas in the brain and correlate to the clinical, histologic, and magnetic resonance findings. Twenty five Swiss-webster mice were infected subcutaneously, and followed for 160 days post-infection. Another group of twenty five mice were not infected and kept as controls. Images were obtained in the different planes by magnetic resonance. Histological samples were stained by Hematoxilin and Eosin (HE) to examine S. mansoni eggs, granulomas and inflammatory lesions. The results showed neurological manifestations as head and chest tilt (to the left or right side), hemiparesis, ataxia, body contortion, loss of balance and spinning, induced by granulomas in several regions of the central nervous system, and vascular changes associated with haemorrages. The MRI indicated multiple irregular nodules dispersed associated with oedema. These findings indicate that the murine model subcutaneously infected by S. mansoni cercarie may be used for studying mechanisms leading to human neuroschistosomiasis.