Related Experiment Video
Updated: Apr 19, 2026
Magnetic Levitation Coupled with Portable Imaging and Analysis for Disease Diagnostics
Published on: February 19, 2017
Evaluation of a density-based rapid diagnostic test for sickle cell disease in a clinical setting in Zambia
Ashok A Kumar1, Catherine Chunda-Liyoka2, Jonathan W Hennek3
1School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America.
Insights
A new low-cost diagnostic test for sickle cell disease (SCD), SCD-AMPS, shows promise for use in developing countries. Field evaluation in Zambia indicated good sensitivity, especially in infants, suggesting potential to improve SCD diagnosis and care.
Area of Science:
- Medical Diagnostics
- Point-of-Care Testing
- Hematology
Background:
- Sickle cell disease (SCD) diagnosis is critical for reducing child mortality in developing nations.
- Limited access to diagnostic tools hinders effective SCD management.
- Aqueous multiphase systems (AMPS) offer a potential low-cost diagnostic solution.
Purpose of the Study:
- To field-evaluate a novel density-based diagnostic test for SCD using aqueous multiphase systems (SCD-AMPS).
- To assess the performance and operability of SCD-AMPS in a resource-limited setting.
Main Methods:
- A case-control study involving 505 participants in Zambia.
- Evaluation of two SCD-AMPS variations, with SCD-AMPS-2 identified as the optimal system.
- Assessment of sensitivity, specificity, and end-user operability by rural health workers.
Main Results:
- SCD-AMPS-2 demonstrated 86% sensitivity and 60% specificity.
- The test showed 84% sensitivity in detecting SCD in infants aged 6-12 months.
- Potential sources of false positives included clotting and variations in test batches/shipping.
Conclusions:
- SCD-AMPS is a viable, low-cost, point-of-care diagnostic candidate for sickle cell disease.
- The test is user-operable by healthcare workers in rural clinics, comparable to existing rapid tests.
- Further refinement is needed to address sources of false positives for improved accuracy.
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.
