1. Background

Prompt, accurate malaria diagnosis at the point of care underpins both effective treatment and the stewardship of antimalarials [1]. Microscopy is skill-dependent, and rapid diagnostic tests (RDTs) lose sensitivity at low parasite densities and where hrp2 deletions occur [2]. Loop-mediated isothermal amplification (LAMP) offers near-PCR sensitivity without thermal cycling, making it a candidate for remote clinics [3]. We evaluated a battery-powered LAMP assay against nested PCR across five remote clinics.

2. Methods

Febrile patients at five clinics were tested in parallel with the LAMP assay, an RDT, and nested PCR as the reference standard. Taking PCR as truth, we computed sensitivity and specificity

$$\text{Se} = \frac{TP}{TP + FN}, \qquad \text{Sp} = \frac{TN}{TN + FP},$$

with 95 percent confidence intervals, and recorded time from sample to result. Operators were clinic staff trained over two days, with weekly external quality-control samples.

3. Results

Against PCR on 1,043 patients, LAMP reached 96.4 percent sensitivity and 98.1 percent specificity, well above the RDT, and returned results in under 45 minutes without cold-chain reagents (Table 1). LAMP detected low-parasitaemia infections missed by the RDT in 11 percent of febrile patients.

4. Discussion and conclusion

Portable LAMP closes much of the sensitivity gap between field tests and PCR while remaining deployable in clinics without laboratories. The trade-offs are a longer time to result than an RDT and the need for trained operators and quality assurance to avoid contamination-driven false positives. Where low-density infections are common, LAMP is a viable point-of-care option; RDTs remain appropriate where speed is paramount and parasitaemia is typically high.