Table 1.
Reference method (RDT, microscopy, PCR) | Illumigene malaria assay | ||||
---|---|---|---|---|---|
Results (n) | Range parasite density (asexual parasites/µL) | Results (n) | Performance | ||
Total | 108 | 108 | |||
Positive | 74 | 74 | Sensitivity (%) (95% CI) | 100% (95.1–100%) | |
Negative | 34 | 34 | Specificity (%) (95% CI) | 100% (89.7–100%) | |
Clinical samples | 96 | ||||
Pf | 27 | (1–372,117) | –* | ||
Pv | 14 | (169–18,777) | –* | ||
Pm | 13 | (106–9244) | –* | ||
Po | 12 | (31–6461) | –* | ||
Mixed | 0 | ||||
Negative | 30 | ||||
External quality controls | 12 | ||||
Pf | 1 | 5 | –* | ||
Pv | 1 | 5 | –* | ||
Pm | 2 | 5 | –* | ||
Po | 3 | 20 | –* | ||
Pk | 1 | 10,000 | |||
Negative | 4 |
The retrospective panel consisted of 103 clinical samples (96 diagnostic samples and 7 samples from patients who already received treatment for malaria infection) and 12 external quality controls. These 7 samples from patients who already received treatment (115 − 7 = 108) were excluded from the calculation of both sensitivity and specificity. Parasite density as quantified by microscopy on blood smear
RDT, rapid diagnostic test; PCR, four-primer real-time PCR; Pf, Plasmodium falciparum; Pm, Plasmodium malariae; Po, Plasmodium ovale; Pv, Plasmodium vivax; Pk, Plasmodium knowlesi; n, number of samples; –*, the illumigene malaria assay does not distinguish between Plasmodium species