Table 1.
Various methods used for diagnostic and surveillance of malaria.
| Method | Target | Sensitivity(percentage of true positives detected) | Specificity(percentage of true negatives detected) | Limit of detection | Cost per sample (USD) | Time | Advantages | Limitations | Reference |
|---|---|---|---|---|---|---|---|---|---|
| Microscopy | N/A | 95% | 98% | 50–200 parasites/μL of blood | $0.12–$0.40 | 60 min | Identification of parasite morphologies, species and stage | Requires trained personnel and microscopes | (Hopkins et al., 2013; Pham et al., 2018; Mbanefo and Kumar, 2020) |
| Rapid Diagnostic Test (RDT) | PfHRP2, PfLDH |
85% to 94.8% | 95.2% to 99% | 50–200 parasites/μL of blood | $0.60-$2.50 | 15–30 min | Fast and easy to use | Mutation in pfhrp-2 leading to false negatives, Unable to quantify parasitaemia, can produce false-positive results well after resolution of infection |
(Cordray and Richards-Kortum, 2012; Hopkins et al., 2013; Pham et al., 2018; Mbanefo and Kumar, 2020) |
| Polymerase Chain Reaction (PCR) | 18S rRNA, cox3, TARE-2, varATS and Pfs25 | 98% to 100% | 88% to 94% | 0.5–5 parasites/μL of blood | $0.35–$5.00 | 1-2 h | Low limit of detection makes it easier to detect low parasitaemia, High throughput, detects drug-resistant parasites, mixed infections |
Requires expensive instruments and reagents and is not able to quantify parasitaemia | (Tangpukdee et al., 2009; Cordray and Richards-Kortum, 2012; Hopkins et al., 2013; Pham et al., 2018,Mbanefo and Kumar, 2020) |
| High-volume quantitative PCR (qPCR) | Plasmodium sp. 18S RNA | 100% | 99.75%. | 0.1 parasite/µl of blood | $0.50 | 45 min-2h | Low limit of detection makes it easier to detect low parasitaemia | Requires expensive instruments and reagents, Requires trained personnel |
(Kamau et al., 2013; Imwong et al., 2014; Haanshuus et al., 2019) |
| Nucleic Acid Sequence-Based Amplification (NASBA) | 18S mRNA | 97.4–100% | 80.9–94% | 0.01–0.1 parasites/μL of blood | $5-$20 | 1–2 h | No thermocycler needed | Requires highly trained personnel, expensive | (Cordray and Richards-Kortum, 2012; Pham et al., 2018; Mbanefo and Kumar, 2020) |
| Loop-mediated Isothermal Amplification (LAMP) | 18S rRNA, mDNA | 98.3% to 100% | 94.3% to 100% | 1–5 parasites/μL of blood | $0.28-$5.31 | 30–60 min | Low limit of detection, faster reaction time than PCR, no thermocycler needed, high throughput |
Easily susceptible to contamination | (Cordray and Richards-Kortum, 2012; Pham et al., 2018; Mbanefo and Kumar, 2020) |
| Serological test | Detection of antibodies against parasites | 69.9% | 100% | 50–200 parasites/μL of blood | $0.50-$5.50 | 30-60 min | Useful for epidemiologic surveys, Relatively cheap, Provides retrospective confirmation of malaria infection |
Not suitable for the diagnosis of acute malaria, Cannot discriminate species | (She et al., 2007; Tangpukdee et al., 2009; Tusting et al., 2014; Goh et al., 2021) |
cox3, Mitochondrial cytochrome c oxidase III; TARE-2,Telomere associated repetitive element; varATS, Var. gene acidic terminal sequence; PfLDH, P. falciparum lactate dehydrogenase; PfHRP2; Plasmodium falciparum histidine-rich protein 2.*Sensitivity and specificity estimates come from (Boonma et al., 2007; Han, 2013) cost estimates come from (Han, 2013) except NASBA (Mbanefo and Kumar, 2020) and serology (Tusting et al., 2014; Goh et al., 2021).