title: Validation of a Low-Cost Paper-Based Screening Test for Sickle Cell Anemia.
abstract: BACKGROUND
  The high childhood mortality and life-long complications associated with sickle cell anemia (SCA) in developing countries could be significantly reduced with effective prophylaxis and education if SCA is diagnosed early in life. However, conventional laboratory methods used for diagnosing SCA remain prohibitively expensive and impractical in this setting. This study describes the clinical validation of a low-cost paper-based test for SCA that can accurately identify sickle trait carriers (HbAS) and individuals with SCA (HbSS) among adults and children over 1 year of age.
  
  
  RESULTS
  In a population of healthy volunteers and SCA patients in the United States (n = 55) the test identified individuals whose blood contained any HbS (HbAS and HbSS) with 100% sensitivity and 100% specificity for both visual evaluation and automated analysis, and detected SCA (HbSS) with 93% sensitivity and 94% specificity for visual evaluation and 100% sensitivity and 97% specificity for automated analysis. In a population of post-partum women (with a previously unknown SCA status) at a primary obstetric hospital in Cabinda, Angola (n = 226) the test identified sickle cell trait carriers with 94% sensitivity and 97% specificity using visual evaluation (none of the women had SCA). Notably, our test permits instrument- and electricity-free visual diagnostics, requires minimal training to be performed, can be completed within 30 minutes, and costs about $0.07 in test-specific consumable materials.
  
  
  CONCLUSIONS
  Our results validate the paper-based SCA test as a useful low-cost tool for screening adults and children for sickle trait and disease and demonstrate its practicality in resource-limited clinical settings.
authors.affiliation: Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana, United States of America.
authors.forename: Nathaniel Z
authors.initials: NZ
authors.lastname: Piety
authors.affiliation: Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana, United States of America.
authors.forename: Xiaoxi
authors.initials: X
authors.lastname: Yang
authors.affiliation: Sickle Cell Center of Southern Louisiana, Tulane University School of Medicine, New Orleans, Louisiana, United States of America.|Department of Pediatrics, Section of Hematology/Oncology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America.
authors.forename: Julie
authors.initials: J
authors.lastname: Kanter
authors.affiliation: Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana, United States of America.
authors.forename: Seth M
authors.initials: SM
authors.lastname: Vignes
authors.affiliation: Department of Pediatrics, Section of Hematology-Oncology, Baylor College of Medicine, Houston, Texas, United States of America.
authors.forename: Alex
authors.initials: A
authors.lastname: George
authors.affiliation: Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana, United States of America.
authors.forename: Sergey S
authors.initials: SS
authors.lastname: Shevkoplyas
mesh_terms: D000328:Adult; D000755:Anemia, Sickle Cell / Q000097:blood / Q000175:diagnosis*; D019540:Area Under Curve; D001331:Automation; D005260:Female; D006451:Hemoglobin, Sickle / Q000737:chemistry*; D006801:Humans; D007223:Infant; D008297:Male; D010209:Paper; D058105:Polymerization; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012995:Solubility
chemical_list: D006451:Hemoglobin, Sickle