Extended Result Reading Window in Lateral Flow Tests Detecting Exposure to Onchocerca volvulus: A New Technology to Improve Epidemiological Surveillance Tools
Open Access
- 23 July 2013
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 8 (7), e69231
- https://doi.org/10.1371/journal.pone.0069231
Abstract
Onchocerciasis is a neglected tropical disease caused by infection with the parasite Onchocerca volvulus (Ov). An estimated 180 million people are at risk for Ov infection, and 37 million people are infected, mostly in Africa. A lateral flow-based assay to detect human IgG4 antibodies to the Ov-specific antigen Ov-16 was developed as a rapid tool to detect exposure to Ov. The test, when performed on 449 sera specimens from patients with microfiladermia and Ov-negative patients, has a sensitivity of 89.1% (95% confidence interval: 86.2%–92.0%), and specificity of 97% (95% confidence interval: 95.4%–98.6%). Because the intended use of the test is for surveillance, it is highly desirable to have a stable, long-lasting result. An extended read window is thus desirable for a high-volume, busy workflow and facilitates post-surveillance quality assurance. The main restriction on achieving an extended read window for this assay was the erythrocyte lysis that can alter the signal-to-noise ratio, especially in those with low IgG4 levels (weak positives). We describe a test housing that incorporates a user-independent feature driven by assay fluid and an expanding wick that detaches the blood separation membrane from the nitrocellulose used in the assay, but before hemolysis occurs. We demonstrated material functionality at extreme operational conditions (37°C, 80% relative humidity) and a read window of a minimum of 70 days. The fluid-driven assay device performs equally as well with whole blood as with plasma, as demonstrated with 100 spiked clinical specimens (with a correlation coefficient of 0.96). We show a novel, inexpensive, and simple approach to actuating the detachment of the blood separation membrane from the nitrocellulose test with no impact on the performance characteristics of the test.Keywords
This publication has 18 references indexed in Scilit:
- Proof-of-Principle of Onchocerciasis Elimination with Ivermectin Treatment in Endemic Foci in Africa: Final Results of a Study in Mali and SenegalPLoS Neglected Tropical Diseases, 2012
- Transmission of Onchocerciasis in Wadelai Focus of Northwestern Uganda Has Been Interrupted and the Disease EliminatedJournal of Parasitology Research, 2012
- Elimination ofOnchocerca volvulusTransmission in the Huehuetenango Focus of GuatemalaJournal of Parasitology Research, 2012
- Impact of long-term treatment of onchocerciasis with ivermectin in Kaduna State, Nigeria: first evidence of the potential for elimination in the operational area of the African Programme for Onchocerciasis ControlParasites & Vectors, 2012
- Onchocerciasis in the Americas: from arrival to (near) eliminationParasites & Vectors, 2011
- Toward Molecular Parasitologic Diagnosis: Enhanced Diagnostic Sensitivity for Filarial Infections in Mobile PopulationsJournal of Clinical Microbiology, 2011
- Feasibility of Onchocerciasis Elimination with Ivermectin Treatment in Endemic Foci in Africa: First Evidence from Studies in Mali and SenegalPLoS Neglected Tropical Diseases, 2009
- A Four-Antigen Mixture for Rapid Assessment of Onchocerca volvulus InfectionPLoS Neglected Tropical Diseases, 2009
- River Blindness: A Success Story under Threat?PLoS Medicine, 2006
- Field Applicability of a Rapid‐Format Anti–Ov‐16 Antibody Test for the Assessment of Onchocerciasis Control Measures in Regions of EndemicityThe Journal of Infectious Diseases, 2006