title: Evaluation of a density-based rapid diagnostic test for sickle cell disease in a clinical setting in Zambia.
abstract: Although simple and low-cost interventions for sickle cell disease (SCD) exist in many developing countries, child mortality associated with SCD remains high, in part, because of the lack of access to diagnostic tests for SCD. A density-based test using aqueous multiphase systems (SCD-AMPS) is a candidate for a low-cost, point-of-care diagnostic for SCD. In this paper, the field evaluation of SCD-AMPS in a large (n = 505) case-control study in Zambia is described. Of the two variations of the SCD-AMPS used, the best system (SCD-AMPS-2) demonstrated a sensitivity of 86% (82-90%) and a specificity of 60% (53-67%). Subsequent analysis identified potential sources of false positives that include clotting, variation between batches of SCD-AMPS, and shipping conditions. Importantly, SCD-AMPS-2 was 84% (62-94%) sensitive in detecting SCD in children between 6 months and 1 year old. In addition to an evaluation of performance, an assessment of end-user operability was done with health workers in rural clinics in Zambia. These health workers rated the SCD-AMPS tests to be as simple to use as lateral flow tests for malaria and HIV.
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: Ashok A
authors.initials: AA
authors.lastname: Kumar
authors.affiliation: Department of Pediatrics, University Teaching Hospital, Lusaka, Zambia.
authors.forename: Catherine
authors.initials: C
authors.lastname: Chunda-Liyoka
authors.affiliation: Department of Chemistry & Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Hennek
authors.affiliation: Department of Pediatrics, University Teaching Hospital, Lusaka, Zambia.
authors.forename: Hamakwa
authors.initials: H
authors.lastname: Mantina
authors.affiliation: Department of Chemistry & Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: S Y Ryan
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Chemistry & Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Patton
authors.affiliation: Department of Pediatrics, University Teaching Hospital, Lusaka, Zambia.
authors.forename: Pauline
authors.initials: P
authors.lastname: Sambo
authors.affiliation: Department of Pediatrics, University Teaching Hospital, Lusaka, Zambia.
authors.forename: Silvester
authors.initials: S
authors.lastname: Sinyangwe
authors.affiliation: Department of Pediatrics, University Teaching Hospital, Lusaka, Zambia.
authors.forename: Chipepo
authors.initials: C
authors.lastname: Kankasa
authors.affiliation: Department of Pediatrics, University Teaching Hospital, Lusaka, Zambia.
authors.forename: Chifumbe
authors.initials: C
authors.lastname: Chintu
authors.affiliation: Department of Laboratory Medicine, Children's Hospital Boston, Boston, Massachusetts, United States of America.
authors.forename: Carlo
authors.initials: C
authors.lastname: Brugnara
authors.affiliation: Hematology Division, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Stossel
authors.affiliation: Department of Chemistry & Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America; Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: George M
authors.initials: GM
authors.lastname: Whitesides
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000175:diagnosis*; D002452:Cell Count; D002648:Child; D002675:Child, Preschool; D003625:Data Collection; D003955:Diagnostic Tests, Routine / Q000191:economics / Q000379:methods*; D004912:Erythrocytes / Q000473:pathology*; D005260:Female; D006282:Health Personnel; D006801:Humans; D007223:Infant; D008297:Male; D019035:Rural Health Services; D013048:Specimen Handling; D013997:Time Factors; D014835:Volatilization; D015024:Zambia