Comparative Validation of Five Quantitative Rapid Test Kits for the Analysis of Salt Iodine Content: Laboratory Performance, User- and Field-Friendliness.

Fabian Rohner,Denis Garnier,Nicolai Petry,Robert Kargougou,Noor Khan,Marcelline O Kangambèga,Ibrahima Sanou,Pieter Jooste,Bertine D Ouaro,James P Wirth,Eliseo A Eugenin

doi:10.1371/journal.pone.0138530

Abstract

BackgroundIodine deficiency has important health and development consequences and the introduction of iodized salt as national programs has been a great public health success in the past decades. To render national salt iodization programs sustainable and ensure adequate iodization levels, simple methods to quantitatively assess whether salt is adequately iodized are required. Several methods claim to be simple and reliable, and are available on the market or are in development.ObjectiveThis work has validated the currently available quantitative rapid test kits (quantRTK) in a comparative manner for both their laboratory performance and ease of use in field settings.MethodsLaboratory performance parameters (linearity, detection and quantification limit, intra- and inter-assay imprecision) were conducted on 5 quantRTK. We assessed inter-operator imprecision using salt of different quality along with the comparison of 59 salt samples from across the globe; measurements were made both in a laboratory and a field setting by technicians and non-technicians. Results from the quantRTK were compared against iodometric titration for validity. An ‘ease-of-use’ rating system was developed to identify the most suitable quantRTK for a given task.ResultsMost of the devices showed acceptable laboratory performance, but for some of the devices, use by non-technicians revealed poorer performance when working in a routine manner. Of the quantRTK tested, the iCheck® and I-Reader® showed most consistent performance and ease of use, and a newly developed paper-based method (saltPAD) holds promise if further developed.ConclusionsUser- and field-friendly devices are now available and the most appropriate quantRTK can be selected depending on the number of samples and the budget available.

Highlights

BackgroundIodine deficiency has important health and development consequences and the introduction of iodized salt as national programs has been a great public health success in the past decades
It is widely accepted that iodine deficiency, even in its milder forms, has important consequences on mental development, intellectual capacity and growth [1]
Salt iodization is a highly cost-effective approach to combating iodine deficiency [2], and universal salt iodization programs in many countries have increased the coverage of iodized table salt over the past two decades, and thereby, reduced iodine deficiency and its disorders

Summary

Background

Iodine deficiency has important health and development consequences and the introduction of iodized salt as national programs has been a great public health success in the past decades. To render national salt iodization programs sustainable and ensure adequate iodization levels, simple methods to quantitatively assess whether salt is adequately iodized are required. Several methods claim to be simple and reliable, and are available on the market or are in development

Methods

Results

Introduction

Material and Methods

Measurement procedures followed

Discussion