Following decantation of the supernatant, the fecal material was weighed and afterwards resuspended in 5% formaldehyde. Next, every mixture was split into three SKLB1002 parts; the first was assigned to FECT and the second and third to the Flotac-400 dual technique using FS4 (315 g NaNO3 plus 685 ml H2O; specific gravity, 1.20 [sodium nitrate, catalog no. A3911; AppliChem]) and FS7 (685 g ZnSO4 plus 685 ml H2O; specific gravity, 1.35 [zinc sulfate, catalog no. A1000; AppliChem]). Of note, FS4 and FS7 were selected from a set of 14 currently available FSs with specific gravities ranging between 1.20 and 1.45 (8, 9). FS4 and FS7 were chosen because they produced the most accurate results for the diagnosis of soil-transmitted helminth and S. mansoni infections in previous studies (8, 20, 21, 39).

Standard protocol for FECT. Each tube containing a homogenized stool sample preserved in 5% formaldehyde was centrifuged for 1 min at 500 �� g. The supernatant was discarded, and 7 ml of 0.85% sodium chloride and 3 ml of diethyl ether were added to the remaining pellet, consisting of 0.5 to 1 ml. The tube was sealed and rigorously shaken in order to bring the diethyl ether in contact with all parts of the remaining fecal material. Following another centrifugation step of 5 min at 500 �� g, four different layers had formed, as follows: (i) a sediment at the bottom, (ii) saline, (iii) fecal debris, and (iv) diethyl ether on the top. The upper three layers were decanted so that only the sediment remained in the tube. This layer was resuspended in a drop of 0.

85% sodium chloride and subsequently placed on a slide, which was examined under a microscope for intestinal protozoa at high magnification (10�� ocular lens, 40�� objective) using oil immersion microscopy. Standard protocol for Flotac-400 dual technique. In the laboratory, FS4 was prepared by dissolving 315 g of NaNO3 in 500 ml tap water, followed by further addition of tap water until a final volume of 1 liter was reached. FS7 was prepared by dissolving 685 g of ZnSO4 ? 7H2O in 685 ml tap water. The specific gravities, 1.20 and 1.35, respectively, were checked with a hydrometer. Subsequently, 10 ml of the fecal suspension was transferred into two tubes each, and the tubes were centrifuged for 3 min at 170 �� g. The supernatant was discarded, and the pellet of one of the tubes was resuspended with 7 ml of 0.

85% sodium chloride and 3 ml of diethyl ether and again centrifuged for 3 min at 170 �� g. This ether washing step was performed to retain fecal debris. Subsequently, the supernatant was discarded and each tube was filled with 5 ml of 0.85% sodium chloride and centrifuged for 3 min at 170 �� g. Following decantation of the supernatant, Drug_discovery each tube was filled to the 6-ml mark using FS7. The other tube, containing the second part of the fecal sample, was filled to the 6-ml mark with FS4 without a prior ether washing step.