Field-friendly techniques for assessment of biomarkers of nutrition for development

Whereas cost-effective interventions exist for the control of micronutrient malnutrition (MN), in low-resource settings field-friendly tools to assess the effect of these interventions are underutilized or not readily available where they are most needed. Conventional approaches for MN measurement are expensive and require relatively sophisticated laboratory instrumentation, skilled technicians, good infrastructure, and reliable sources of clean water and electricity. Consequently, there is a need to develop and introduce innovative tools that are appropriate for MN assessment in low-resource settings. These diagnostics should be cost-effective, simple to perform, robust, accurate, and capable of being performed with basic laboratory equipment. Currently, such technologies either do not exist or have been applied to the assessment of a few micronutrients. In the Demographic and Health Surveys (DHS), a few such examples for which "biomarkers" of nutrition development have been assessed in low-resource settings using field-friendly approaches are hemoglobin (anemia), retinol-binding protein (vitamin A), and iron (transferrin receptor). In all of these examples, samples were collected mainly by nonmedical staff and analyses were conducted in the survey country by technicians from the local health or research facilities. This article provides information on how the DHS has been able to successfully adapt field-friendly techniques in challenging environments in population-based surveys for the assessment of micronutrient deficiencies. Special emphasis is placed on sample collection, processing, and testing in relation to the availability of local technology, resources, and capacity.