Effects of Inorganic Fertilizers on the Mortality of Schistosoma mansoni Cercariae and their Infectivity in the Albino Mice

Abstract

The effect of four brands of inorganic fertilizers on the mortality rate of Schistosoma mansoni cercariae were investigated under laboratory conditions. The brands of fertilizers used were: Urea, Single Super Phosphate (SPP), Nitrogen-Phosphorus-Potassium (NPK) – 27:13:13 and NPK – 15:15:15. A total of 150 cercariae were exposed to various acute concentrations of the fertilizers and the percentage mortality over a 24 hour exposure period monitored. The SSP was observed to be most toxic, while urea was the least toxic. For the infectivity experiment, the cercariae were treated with known sub-lethal concentrations of the fertilizers, and thereafter their infectivity in the male albino mice (DBA strain) were investigated. The mice infected with cercariae treated with urea had the highest mean worm yield, while the SSP treated carceriae had the least. The implications of these results in relation to the control of schistosomiasis are discussed.

Journal of Aquatic Sciences Volume 15, April 2000, pp. 27-30



KEY WORDS:

Inorganic fertilizers, toxicology, infectivity, Schistosoma, mice.