A historical review of the techniques of recovery of parasites for their detection in human stools

Abstract Since the early 20th century, the detection of intestinal parasites has improved with the development of several techniques for parasitic structures recovery and identification, which differ in sensitivity, specificity, practicality, cost, and infrastructure demand. This study aims to review, in chronological order, the stool examination techniques and discuss their advantages, limitations, and perspectives, and to provide professionals and specialists in this field with data that lays a foundation for critical analysis on the use of such procedures. The concentration procedures that constitute the main techniques applied in routine research and in parasitological kits are a) spontaneous sedimentation; b) centrifugation-sedimentation with formalin-ethyl acetate; and c) flotation with zinc sulfate solution. While selecting a technique, one should consider the purpose of its application and the technical-operational, biological, and physicochemical factors inherent in the procedures used in stool processing, which may restrict its use. These intrinsic limitations may have undergone procedural changes driven by scientific and technological development and by development of alternative methods, which now contribute to the improvement of diagnostic accuracy.

A study of intestinal parasites in children of an urban region with excellent sanitary condition reveals high occurrence of Blastocystis spp

Intestinal parasites are among the major causative agents of diseases that affect animals and humans, especially children. In view of this, the current study evaluated the occurrence of these parasitic agents in 737 children in an urban region with excellent sanitation condition of the city of Pedreira, São Paulo, Brazil. Fecal samples from the children were processed with the use of a technique of high diagnostic efficiency (TF-Test®). The diagnosis of these samples resulted in the detection of 557 parasitic structures among eleven genera of parasites, and of 46.4% (342/737) infected children. Blastocystis spp. was found in 69.6% (238/342) of the positive samples and the monoparasitism was accompanied by symptoms in 44 children. Furthermore, 67.8% (232/342) of the infected children had close contact with pets, suggesting a possible zoonotic transmission. Lastly, this study allowed to perform health education to the children, aiming the reduction of new intestinal parasitic infections.