Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/183414
Title: Utility of ultra-sensitive qPCR to detect Plasmodium falciparum and Plasmodium vivax infections under different transmission intensities
Author: Gruenberg, Maria
Antunes Moniz, Clara
Hofmann, Natalie E.
Koepfli, Cristian
Robinson, Leanne J.
Nate, Elma
Monteiro, Wuelton Marcelo
Cardoso de Melo, Gisely
Kuehn, Andrea
Siqueira, Andre M.
Nguitragool, Wang
Bassat Orellana, Quique
Lacerda, Marcus
Sattabongkot, Jetsumon
Mueller, Ivo
Felger, Ingrid
Keywords: Diagnòstic molecular
Plasmodium falciparum
Plasmodium vivax
Molecular diagnosis
Plasmodium falciparum
Plasmodium vivax
Issue Date: 2020
Publisher: BioMed Central
Abstract: Background: The use of molecular diagnostics has revealed an unexpectedly large number of asymptomatic low-density malaria infections in many malaria endemic areas. This study compared the gains in parasite prevalence obtained by the use of ultra-sensitive (us)-qPCR as compared to standard qPCR in cross-sectional surveys conducted in Thailand, Brazil and Papua New Guinea (PNG). The compared assays differed in the copy number of qPCR targets in the parasite genome. Methods: Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) parasites were quantified by qPCR amplifying the low-copy Pf_ and Pv_18S rRNA genes or the multi-copy targets Pf_varATS and Pv_mtCOX1. Cross-sectional surveys at the three study sites included 2252 participants of all ages and represented different transmission intensities. Results: In the two low-transmission areas, P. falciparum positivity was 1.3% (10/773) (Thailand) and 0.8% (5/651) (Bra- zil) using standard Pf_18S rRNA qPCR. In these two countries, P. falciparum positivity by Pf_varATS us-qPCR increased to 1.9% (15/773) and 1.7% (11/651). In PNG, an area with moderate transmission intensity, P. falciparum positivity significantly increased from 8.6% (71/828) by standard qPCR to 12.2% (101/828) by us-qPCR. The proportions of P. falciparum infections not detected by standard qPCR were 33%, 55% and 30% in Thailand, Brazil and PNG. Plasmodium vivax was the predominating species in Thailand and Brazil, with 3.9% (30/773) and 4.9% (32/651) positivity by Pv_18S rRNA qPCR. In PNG, P. vivax positivity was similar to P. falciparum, at 8.0% (66/828). Use of Pv_mtCOX1 us-qPCR led to a significant increase in positivity to 5.1% (39/773), 6.4% (42/651) and 11.5% (95/828) in Thailand, Brazil, and PNG. The proportions of P. vivax infections missed by standard qPCR were similar at all three sites, with 23%, 24% and 31% in Thailand, Brazil and PNG. Conclusion: The proportional gains in the detection of P. falciparum and P. vivax infections by ultra-sensitive diag- nostic assays were substantial at all three study sites. Thus, us-qPCR yields more precise prevalence estimates for both P. falciparum and P. vivax at all studied levels of endemicity and represents a significant diagnostic improvement.
Note: Reproducció del document publicat a: http://dx.doi.org/10.1186/s12936-020-03374-7
It is part of: Malaria Journal, 2020, vol. 19, num. 1, p. 319
URI: http://hdl.handle.net/2445/183414
Related resource: http://dx.doi.org/10.1186/s12936-020-03374-7
ISSN: 1475-2875
Appears in Collections:Articles publicats en revistes (ISGlobal)

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