How quantitative rapid test kits will support efforts to reduce iodine deficiency disorders
Learn what our expert found out after reviewing five portable kits that test salt iodization levels while in the field.
Posted on April 28, 2016
Senegal is West Africa’s largest salt producer, meeting the salt needs domestically and regionally. In 2014, with MI support, 382 million additional people were estimated to have access to adequately iodized salt.
Iodine deficiency is a major cause of preventable brain damage in childhood.
It reduces a person’s intellectual capacity, mental development and growth, impacting their life forever at home, school and work. Iodine deficiency disorders (IDD) continue to be a public health problem in populations globally, particularly pregnant women and young children.
Over the past 20 years, countries worldwide have implemented salt iodization – an affordable solution to prevent iodine deficiency and its consequent iodine deficiency disorders.
Iodizing salt has proven to be the most effective, simple and inexpensive weapon against iodine deficiency disorders and MI has been working successfully with countries to ensure adequately iodized salt. However, despite being on the verge of eliminating IDD, more work is needed as 54 countries are still considered iodine deficient.
It is no longer sufficient to merely verify the presence or absence of iodine in salt in our efforts to provide adequately iodized salt as a way to fight iodine deficiency disorders.
To properly support monitoring efforts – and sustainability – of iodine levels in salt, it is critical to know the actual amount of iodine we add to salt, so we can judge whether the salt is adequately iodized.
Currently, laboratory-based analytical methods, such as iodometric titration, exists that quantitatively assess iodine content in salt. Yet, it is more challenging to perform such assessments at the level of production, importation and consumption because providing laboratory facilities, equipment and skill personnel is often difficult in resource constrained situations.
To properly support sustainability and monitoring of this critical IDD intervention, laboratory technicians and non-technicians around the world need access to simple and reliable methods of assessing iodine concentrations in salt during fieldwork.
While for most settings iodometric titration has been accepted as the reference method, a number of apparently more user and field friendly analytical devices for the quantitative assessment of salt iodine content – called quantitative rapid test kits or quantRTK – have become available recently.
These devices are tailor-made for testing salt iodine content in the field. They do not require the existence of a physical laboratory setting, equipment and skilled staff to conduct the tests properly, thus are provide results quickly and at much lower costs.
However, the question remains as to which device will best serve program needs, especially since quantRTK devices are new and a number of different types used in different programs worldwide.
To address this issue, I – along with a team of 10 researchers from Switzerland, Burkina Faso, and South Africa – compared five currently available quantRTKs in terms of performance both in the laboratory and in the field. We wanted the results to provide evidence-based guidance to professional NGO staff and the UN, as well as to governments and industry around the world.
The overall rating for each device was determined by:
Most of the devices tested showed acceptable laboratory performance but, for some of the devices, use by non-technicians revealed poor performance when working using routine procedures.
In addition, we also took care to evaluate the “softer” parameters, including cost, skills required and device ruggedness, as objectively as possible to ensure a fair and accurate rating of each device.*
The full methods and dataset can be found at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0138530
Both iodometric titration and quantRTK are subject to error, and should accompany appropriate quality assurance procedures to help ensure that measurement issues are identified in time.
The bottom line is, in the field quantRTK devices simplify salt iodine content monitoring, reduce costs associated with monitoring, and increase efficiency, which can help build program sustainability and – in the long term – help us reach the end of iodine deficiency disorders.