Transmission of Schistosoma mansoni under experimental conditions using the bovine - Biomphalaria glabrata - bovine model

Abstract

Three calves experimentally infected with Schistosoma mansoni, and passing viable eggs in feces, as well as 5 normal calves (coming from a non-endemic area for schistosomiasis) kept as controls, were maintained in an enclosure (850 m² in area). In this enclosure, a tank with water received 500 laboratory reared Biomphalaria glabrata. All the control calves were infected for a period ranging from 79 to 202 days after the beginning of the experiment, and afterwards presented viable S. mansoni eggs in feces. The mean worm recovery was 555. The snail population increased throughout the experimental period, showing a high number of B. glabrata infected with S. mansoni (42% on average). According to the present study, bovine has been suggested as having potentially a role in the maintenance of the life cycle of S. mansoni

Experimental schistosomiasis in the Common Marmoset Callithrix jacchus

“…higher in animals infected subcutaneously. Cows infected with 25,000 cercariae first showed eggs in their feces between 79 and 202 days pi 27 . The fact that no eggs were seen in feces of infected C. jacchus may be explained by an immunological factor characteristic of the specis.…”

Biological implications of the phenotypic plasticity in the Schistosoma mansoni - Nectomys squamipes model

“…However, rodents in both the Africa and the Neotropics also develop natural infection 1,9,24,35 . In addition, the possibility of closing the S. mansoni cycle without human participation had been demonstrated with rodents 2 or bovine 22 acting as final host. In Brazil, the water rat Nectomys squamipes (Rodentia:Sigmodontinae) is an important nonhuman host in schistosomiasis transmission, due to its susceptibility, high abundance, water-contact pattern 6 , and daily activities 4 .…”