RESUMO
Three methods for the detection of Schistosome cercariae in water were studied under laboratory and simulated field conditions in Egypt. Water samples tested by filtration and centrifugation, quantitatively, reflected the density of cercariae in moderately turbid canal water [30 nephelometry Turbidity Unites, NTU]. When tested in waters of increasing turbidity, the centrifuge gave more consistent results than the filtration system. The centrifugation technique was more efficient in processing the water samples and took almost half the time of filtration and mouse exposure was useful in detecting cercariae, but was not quantitative. However, there was a significant improvement in worm recovery when mice were more close together in the floatation device. Mouse exposure was also expensive and cumbersome to use. The present results concluded that centrifugation may be considered the technique of choice for further cercariometric work under the Egyptian conditions
Assuntos
Esquistossomose mansoni/isolamento & purificação , Poluição da ÁguaRESUMO
The effect of pairing on the susceptibility of male Syrian hamsters to Schistosoma mansoni infection in comparison with their isolated counterparts has been studied. Pairing resulted in significant differences between paired and isolated hamsters in the measurements of eggs, miracidia, number of adult worms recovered and mean testicular number of males. Paired hamsters seemed to be immunologically suppressed and such a suppression resulted in increasing the fertility and number of worms recovered. The width of the male Schistosomes recovered from the paired hamsters was two folds and the length was four folds greater than those recovered from isolated ones. It was concluded that the stressed host reflected effects on the number and fertility of the schistosome worms burden, hence the severity of the disease and its complications