Point of Care Testing for Malaria Using LAMP, Loop Mediated Isothermal Amplification

For over a century the laboratory diagnosis of malaria has relied on visualization of the parasite in blood smears. But microscopy is time and labor consuming and often inaccurate due to the considerable training and experience required. About 2 decades ago, immunochromatographic rapid diagnostic tests (RDTs) were introduced, providing a simpler and more rapid point of care diagnostic. However, RDTs, like blood smears, are limited in the detection of low-density infections. Nucleic acid amplification based assays offer markedly improved sensitivity, but standard polymerase chain reaction (PCR) diagnostics require hours of processing time, sophisticated technical skill, and expensive equipment to perform. Loop mediated isothermal amplification (LAMP) may offer the best of both worlds for malaria diagnostics, with the sensitivity of PCR but speed closer to that of RDTs. Highly sensitive diagnostics may not be appropriate in all situations. Patients with symptomatic malaria generally have high-density infections that are detectable by blood smears or RDTs, and in resource-limited settings, use of a more sophisticated assay may not be practical. However, when the goal is to interrupt transmission or eliminate malaria, there is a need to detect all infections, including asymptomatic infections, which are usually of low density [1]. In these low-endemic settings, subpatent infections, or those below the detection level of microscopy or RDT, are estimated to result in 20%–50% of all transmission episodes [2]. A malaria program that is serious about elimination cannot ignore these infections [3].