Enhanced efficacy of praziquantel treatment in mice vaccinated with radiation attenuated cercariae of schistosoma mansoni

ABSTRACT

Normal and vaccinated mice, 4 weeks previously, with radiation attenuated cercariae of S. mansoni [500/mouse] were challenged with normal cercariae [150/mouse], then treated at 1 week later with praziquantel [400 mg/kg body weight, orally]. Worm burden was determined to calculate the percent of immunity in all groups under study. Histopathological examination of liver, small and large intestine, spleen and lung was done. Serum IgE level was estimated using the immunoradiometric assay [IRMA]. The percent of immunity was highest among vaccinated, infected and treated groups with minimal pathological changes recorded and highest IgE level. From the data collected, it was found that the efficacy of praziquantel treatment was enhanced in vaccinated mice and there was a synergistic effect between drug treatment and vaccination when praziquantel was given at seven days post-infection [challenge]