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

Felipe Augusto Soares,Stefany Laryssa Rosa,Saulo Hudson Nery Loiola,Walter Bertequini Nagata,Sandra Valéria Inácio,Alexandre Xavier Falcão,Celso Tetsuo Nagase Suzuki,Aline Do Nascimento Benitez,Bianca Martins Dos Santos,Katia Denise Saraiva Bresciani,Jancarlo Ferreira Gomes

doi:10.1590/0037-8682-0535-2019

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.

Highlights

Human intestinal parasites are a global public health issue, primarily when associated with poor sanitary and socioeconomic conditions in tropical and subtropical climate areas[1,2]
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

Summary

Introduction

Human intestinal parasites are a global public health issue, primarily when associated with poor sanitary and socioeconomic conditions in tropical and subtropical climate areas[1,2]. Diseases caused by these parasites are endemic in less developed communities in various peripheral regions of the planet[3]. Entamoeba histolytica/E. dispar, Giardia spp., and Cryptosporidium spp. are among the most commonly reported parasites in pre-school and school-age children in developing countries with poor sanitation and hygiene conditions[12,13] These protozoa cause high morbidity in immunocompromised patients[14]. These are found in more than one billion people in sub-Saharan Africa, Latin America, China, and East Asia[18]

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Conclusion