Fig 1.
Microscopy images from samples initially classified as indeterminate but later confirmed to be P. knowlesi.
(a) early trophozoite resembling P. falciparum; (b) trophozoite resembling P. vivax; (c and d) late trophozoite resembling P. malariae; (e) multi-nucleated schizont and (f) gametocyte resembling P. falciparum.
Table 1.
Species classification of microscopy-positive samples by loop mediated isothermal amplification (LAMP), cytb nPCR, 18S rRNA nPCR, Plasmodium knowlesi-specific nPCR, and the serial molecular testing as gold standard.
Fig 2.
Loop mediated isothermal amplification (LAMP) detection of malaria.
Pan-LAMP accurately identified malaria positive samples, later confirmed as P. vivax (tube 1) and P. knowlesi (tube 6).
Fig 3.
Mis-classification or missed malaria species identification using standard PCR.
a) AluI digestion of cytochrome-b nPCR product for species determination [23]. Pk control (lane 6) with similar banding pattern as Pv control (lane 3). Pk field sample 1548 (lane 7) incorrectly classified as Pv. Pv field sample 1626 (lane 8) accurately identified as Pv; b) 18S rRNA nPCR results utilizing Pv specific primers [24]. Pv field sample 1626 (lane 4) accurately identified as Pv and Pk field sample 1548 (lane 5) not successfully amplified; c) Pk-specific nPCR [16]. Successful amplification of Pk field sample 1548 but not Pv field sample 1626. M: Molecular weight marker; Pf: Plasmodium falciparum; Pv: P. vivax; Pm: P. malariae; Po: P. ovale; Pk: P. knowlesi.
Table 2.
Positive predictive values for species identification by different diagnostic methods using the gold standard of serial molecular testing.