The Specific Gravity of Hookworm Eggs

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  • Department of Tropical Medicine, Tulane University of Louisiana, New Orleans, La.
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Concentration methods for the recovery of parasites from fecal specimens by sedimentation, levitation, centrifugation and centrifugal-floatation are based upon the physical and chemical differences of the parasites and their environmental media. One of the physical properties involved in these concentration technics is specific gravity. This paper deals with studies on the specific gravity of eggs of Necator americanus.

In 1923, Mhaskar (1) examined the specific gravity of Ancylostoma duodenale eggs and his data appear to be the only record in the literature on the specific gravity of hookworm eggs. Mhaskar used a suspension of one part of hookworm-infected feces in 40 parts of several chemical solutions having various specific gravities. The solutions were prepared with magnesium sulphate, calcium chloride, glycerine or a mixture of saturated magnesium sulphate solution and glycerine in equal parts. These suspensions were left to stand in a test tube and after half an hour the supernatant fluid was pipetted off into another test tube.

Author Notes

This communication is one of a series entitled “A Critical Study of Clinical Laboratory Technics for the Diagnosis of Protozoan Cysts and Helminth Eggs in Feces,” by the Amebiasis Unit of the National Institute of Health at Tulane University, under the direction of Ernest Carroll Faust.