Mini-FLOTAC, an Innovative Direct Diagnostic Technique for Intestinal Parasitic Infections: Experience from the Field

Beatrice Divina Barda,Davide Ianniello,Laura Rinaldi,Giuseppe Cringoli,Tsetan Sadutshang,Massimo Clementi,Fulvio Salvo,Henry Zepherine,Marco Albonico,Peter Steinmann

doi:10.1371/journal.pntd.0002344

Abstract

BackgroundSoil-transmitted helminths and intestinal protozoa infection are widespread in developing countries, yet an accurate diagnosis is rarely performed. The aim of this study was to evaluate the recently developed mini–FLOTAC method and to compare with currently more widely used techniques for the diagnosis of intestinal parasitic infections in different settings.Methodology/Principal FindingsThe study was carried out in Dharamsala, Himachal Pradesh, India, and in Bukumbi, Tanzania. A total of 180 pupils from two primary schools had their stool analyzed (n = 80 in Dharamsala and n = 100 in Bukumbi) for intestinal parasitic infections with three diagnostic methods: direct fecal smear, formol-ether concentration method (FECM) and mini-FLOTAC. Overall, 72% of the pupils were positive for any intestinal parasitic infection, 24% carried dual infections and 11% three infections or more. The most frequently encountered intestinal parasites were Entamoeba coli, Entamoeba histolytica/dispar, Giardia intestinalis, hookworm, (and Schistosoma mansoni, in Tanzania). Statistically significant differences were found in the detection of parasitic infections among the three methods: mini-FLOTAC was the most sensitive method for helminth infections (90% mini-FLOTAC, 60% FECM, and 30% direct fecal smear), whereas FECM was most sensitive for intestinal protozoa infections (88% FECM, 70% direct fecal smear, and 68% mini-FLOTAC).Conclusion/SignificanceWe present the first experiences with the mini-FLOTAC for the diagnosis of intestinal helminths and protozoa. Our results suggest that it is a valid, sensitive and potentially low-cost alternative technique that could be used in resource-limited settings — particularly for helminth diagnosis.

Highlights

Soil-transmitted helminths (STH) (Ascaris lumbricoides, Trichuris trichiura, hookworm, Strongyloides stercoralis) and intestinal protozoa (e.g. Giardia intestinalis, Entamoeba histolytica/dispar) are widespread in developing countries, especially where poor hygienic conditions facilitate infection with eggs, larvae and cysts through contact with contaminated soil, food or water
Our study was carried out in Dharamsala, India, and in Bukumbi, Tanzania in order to evaluate the methods under different field conditions and diverse parasitic infection profiles
Mini-FLOTAC detected the highest number of helminth infections (90% sensitivity), whereas the formol-ether concentration was the most sensitive approach for intestinal protozoa infections (88% sensitivity)

Summary

Introduction

Soil-transmitted helminths (STH) (Ascaris lumbricoides, Trichuris trichiura, hookworm, Strongyloides stercoralis) and intestinal protozoa (e.g. Giardia intestinalis, Entamoeba histolytica/dispar) are widespread in developing countries, especially where poor hygienic conditions facilitate infection with eggs, larvae and cysts through contact with contaminated soil, food or water. Soil-transmitted helminth infections in endemic countries are a major cause of malnutrition, anemia and growth delay. Often they are linked to minor symptoms such as sub-acute diarrhea or can occur in a subtle and asymptomatic way and are often underreported [2]. Soil-transmitted helminths and intestinal protozoa infection are widespread in developing countries, yet an accurate diagnosis is rarely performed. The aim of this study was to evaluate the recently developed mini–FLOTAC method and to compare with currently more widely used techniques for the diagnosis of intestinal parasitic infections in different settings

Objectives

Methods

Results

Discussion

Conclusion