Efficacy of five chemicals on fasciola gigantica encysted metacercariae infectivity

The efficacy of treating encysted metacercariae [EMC] of Fasciola gigantica with different concentrations [conc] of acetic acid, citric acid, cetrimide, potassium permanganate and sodium hydroxide, for 15 and 30 minutes was evaluated. The efficacy of these chemicals on the vitality and infectivity of the EMC was evaluated by the development of fascioliasis infection, and the histopathological changes in the livers of experimentally infected Albino rabbits. The results showed that 1% sodium hydroxide had a lethal effect on EMC, 10% to 40% potassium permanganate destroyed the infectivity power of EMC, and acetic acid gave an adverse effect on the EMC in cone, more than 2.5%. But, neither citric acid nor cetrimide affected the vitality or infectivity of EMC and all rabbits acquired fascioliasis

Efficacy of temperature, and two commonly used molluscicides and fertilizers on fasciola gigantica eggs

This study .evaluated the effect of temperature, molluscicides [Copper sulphate and Niclosamide], fertilizers [Superphosphate and Ammonium sulphate] on the hatchability of Fasciola gigantica eggs. The results showed that hatchability decreased to 4% when eggs were incubated in bile secretion at 37°C for 5 days and to 1.4% for 10 days, but few eggs incubated in water at 37°C hatched. Bile secretion at 37°C was a poor medium for in-vitro egg preservation. But, hatching occurred only when eggs were transferred to water at 26°C. Temperature fluctuation from 26-4°C or from 32- 4°C had an inhibitory effect on embryos development [35.2% and 32.3%, respectively] as compared to controls [60% and 63.9%, respectively]. The incubation period [19 and 17 days] was higher than controls [14 and 12 days, respectively]. The LC50 and LC9o of Copper sulphate and Niclosamide against Biomphalaria alexandrina and Lymnaea natalenesis had no toxic effect on Fasciola eggs. The higher concentrations of Copper sulphate [30ppm] and Niclosamide [Ippm] slightly lower eggs hatchability rate than controls. The rate decreased by increasing the exposure time from 3 to 6 hours with both molluscicides. Ammonium sulphate had a lethal effect on eggs, but Superphosphate had some inhibitory effect on egg development, which increased by increasing Superphosphate concentration or with the prolongation of the exposure time