Application of dried blood spot sample pooling strategies for Plasmodium 18S rRNA biomarker testing to facilitate identification of infected persons in large-scale epidemiological studies

Table 4 Measurements and percentages of detection rates for varied concentrations of P. falciparum Armored RNA® in liquid and DBS samples by the simplified assay

Pf Armored RNA® Dilution		Liquid samples (log₁₀ copies/mL blood)				DBS samples (log₁₀ copies/mL blood)
Parasites/mL blood	Log₁₀ copies/mL blood	Pf qRT-PCR		Pan qRT-PCR		Pf qRT-PCR		Pan qRT-PCR
Parasites/mL blood	Log₁₀ copies/mL blood	Mean	SD	Mean	SD	Mean	SD	Mean	SD
2.4 × 10⁵	9.2	9.0	0.2	8.9	0.3	8.6	0.3	8.6	0.3
2.8 × 10⁴	8.3	8.5	0.2	8.0	0.2	7.7	0.4	7.7	0.3
2,8 × 10³	7.3	6.9	0.1	7.0	0.2	6.7	0.3	6.6	0.2
2.8 × 10²	6.3	5.9	0.1	5.9	0.2	5.6	0.4	5.7	0.3
2.8 × 10¹	5.3	4.8 (3/4*)	n/a	4.9	0.2	4.8 (6/8*)	n/a	4.8	0.3
1.7 × 10¹	5.1	4.8 (3/4*)	n/a	4.8	0.2	4.7 (6/10*)	n/a	4.6	0.4
7	4.7	0.0 (0/4*)	n/a	4.1	0.3	3.4 (5/11*)	n/a	3.2 (9/11*)	n/a

Pf P. falciparum, Pan pan-Plasmodium
n/a not applicable (SD not calculated for replicates of < 100% detection rate)
SD reflects variation in two batches of samples measured by multiple operators; n = 4–11 samples per concentration level
*Average calculated for quantifiable samples only (numbers in parentheses are detected results/number of replicates tested)

ISSN: 1475-2875