Dried Blood Spots for Global Health Diagnostics and Surveillance: Opportunities and Challenges.

There is increasing interest in using dried blood spot (DBS) cards to extend the reach of global health and disease surveillance programs to hard-to-reach populations. Conceptually, DBS offers a cost-effective solution for multiple use cases by simplifying logistics for collecting, preserving, and transporting blood specimens in settings with minimal infrastructure. This review describes methods to determine both the reliability of DBS-based bioanalysis for a defined use case and the optimal conditions that minimize pre-analytical sources of data variability. Examples by the newborn screening, drug development, and global health communities are provided in this review of published literature. Sources of variability are linked in most cases, emphasizing the importance of field-to-laboratory standard operating procedures that are evidence based and consider both stability and efficiency of recovery for a specified analyte in defining the type of DBS card, accessories, handling procedures, and storage conditions. Also included in this review are reports where DBS was determined to not be feasible because of technology limitations or physiological properties of a targeted analyte.