TABLE 3

Number of samples per reference result for all samples with a P. falciparum-positive uRDT and a P. falciparum-negative result for at least one reference (of references A to C)a

Test location and Quansys ELISA result (type of antigens identified)bNo. of samples with uPCR result (type of DNA identified)b
NoneP. vivaxPlasmodium spp.P. falciparum
Laboratory
    None3c1c0c2f
    P. vivax (PvLDH)0c1c0c0f
    P. falciparum (PfHRP2)2d0e4eNA
    P. falciparum and P. vivax (PfHRP2 plus PvLDH)0d1e2eNA
    Plasmodium spp. (PanLDH only)0c0c0c2f
Field
    None1c1c0c0f
    P. vivax (PvLDH)0c2c0c1f
    P. falciparum (PfHRP2)0d1e3eNA
    P. falciparum and P. vivax (PfHRP2 plus PvLDH)0d0e0eNA
    Plasmodium spp. (PanLDH only)0c0c0c1f
  • a A color-coded version of Table 3 is available in the supplemental material (Table S1).

  • b See footnotes c to f below. Values with footnotes c and d are false-positive results by reference C (n = 7 for laboratory and n = 4 for field). Values with footnotes c and f are false-positive results by reference A (n = 9 for laboratory and n = 6 for field). Values with footnotes c, d, and e are false-positive results by reference B (n = 14 for laboratory and n = 8 for field). NA, not applicable (corresponds to PfHRP2-positive and PfDNA-positive samples [true positive according to all references]).

  • c P. falciparum-negative samples by all three reference methods. These are most likely false-positive uRDT results.

  • d PfHRP2-positive, PfDNA-negative, and Plasmodium DNA-negative samples (positive by reference A only). These two samples could correspond to recently cleared infections with persisting HRP2 antigenemia.

  • e PfHRP2-positive, PfDNA-negative, and Plasmodium DNA-positive samples (P. falciparum positive by reference A and C).

  • f PfHRP2 negative and PfDNA positive (P. falciparum positive by reference B and C).