Post-treatment duration of positivity for standard and ultra-sensitive Plasmodium falciparum antigen-based rapid diagnostic tests, a cohort study from a low-endemic setting in NamibiaResearch in context

Background: The standard malaria rapid diagnostic test (RDT) and newer ultra-sensitive RDT (uRDT) target Plasmodium falciparum histidine rich protein-2 (HRP2), which persists post-treatment. The duration of test positivity has not previously been studied in a low transmission setting. Methods: We co...

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Bibliographic Details
Published in:EBioMedicine 2025-01, Vol.111, p.105489
Main Authors: Henry Ntuku, Brooke Whittemore, Lucille Dausab, Ihn Kyung Jang, Allison Golden, William Sheahan, Xue Wu, Hannah Slater, Gonzalo J. Domingo, Smita Das, Elias Duarte, Lydia Eloff, Teun Bousema, Kjerstin Lanke, Cara Smith Gueye, Lisa M. Prach, Jaishree Raman, Petrina Uusiku, Stark Katokele, Roly Gosling, Bryan Greenhouse, Davis Mumbengegwi, Michelle S. Hsiang
Format: Article
Language:English
Subjects:
Histidine-rich protein
Low transmission
Low-endemic
Malaria
Malaria elimination
Persistence
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Summary:Background: The standard malaria rapid diagnostic test (RDT) and newer ultra-sensitive RDT (uRDT) target Plasmodium falciparum histidine rich protein-2 (HRP2), which persists post-treatment. The duration of test positivity has not previously been studied in a low transmission setting. Methods: We conducted a longitudinal cohort study in a low transmission setting in Namibia. RDT-positive individuals identified through passive and active case detection were treated and followed weekly for testing by RDT and uRDT, HRP2 quantification, quantitative PCR (qPCR) of parasitemia, and quantitative reverse transcriptase PCR (RT-PCR) of gametocytemia, until RDT and uRDT were negative for two consecutive weeks. Determinants of persistent positivity were identified using Cox proportional hazards models. Findings: Among 137 participants with complete follow-up and no evidence of resurgence during follow-up, median duration of positivity was 42 days (range: 3−98 range) for RDT, compared to 67 days (range 12–105) for uRDT. In a sub-analysis of those with laboratory data before treatment (n = 60), drug resistance did not explain persistent positivity. Younger age (
ISSN:2352-3964