Detection of malaria parasites in samples from returning US travelers using the Alethia® Malaria Plus LAMP assay

Abstract

Objective In this study, the performance of a commercially available malaria LAMP assay (Alethia® Malaria Plus LAMP) was evaluated using retrospective clinical samples obtained from travelers returning to the United States of America (USA). Recently, several laboratories in non-malaria endemic countries evaluated the use of the loop mediated isothermal amplification (LAMP) assays for the diagnosis of imported malaria cases. These tests are simpler than polymerase-chain reaction (PCR)-based assays and were shown to have high sensitivity. Much of malaria diagnoses in the USA, is undertaken at the state level using mainly microscopy and rapid diagnostic tests (RDTs). However, molecular tools offer greater sensitivity over microscopy and RDTs. A reliable, easy to perform molecular assay can provide a test of choice for the accurate detection of malaria parasites in places where expert microscopy is lacking and/or for the detection of low-parasite density infections. Results The Alethia® Malaria Plus LAMP assay was easy to use, had similar test performances as the real-time PCR reference test and results were obtained faster (within 1 h) than the reference test. The sensitivity of the assay was 100% with a kappa score of 1 when compared to the reference PET-PCR assay.

Usefulness of a commercial LAMP assay for detection of malaria infection, including Plasmodium knowlesi cases, in returning travelers in Spain

“…Conventional methods, such as microscopy and RDTs, lack sensitivity, while PCR-based methods, although very sensitive [ 8 ], require highly trained personnel and expensive equipment. In contrast, LAMP-based methods have proven to have a similar or higher sensitivity than PCR methods but with the need for less training and resources [ 19 , 24 ]. Alethia ® Malaria kit is a qualitative commercial assay able to detect Plasmodium spp.…”

“…In a study performed in France [ 2 ], they obtained 100% of sensitivity and 98.13% specificity using real-time PCR as the reference method. Studies performed in North America obtained excellent sensitivity compared to microscopy [ 16 ] and PCR [ 19 ]. Moreover, the Alethia ® Malaria kit has also been evaluated in Senegal obtaining high sensitivity (97.2%) and a good specificity [ 15 ].…”

“…One of these commercial LAMP kits is Alethia ® Malaria LAMP assay (Meridian Bioscience), previously called illumigene ® Malaria, which is a qualitative in vitro diagnostic LAMP test for detection of Plasmodium spp. that has been tested in endemic [ 15 ] and in non-endemic malaria countries [ 2 , 16 , 18 , 19 ]. However, most of the published studies assessing Plasmodium spp.…”

“…However, most of the published studies assessing Plasmodium spp. samples using Alethia ® Malaria LAMP assay included none or very few samples of Plasmodium knowlesi parasites [ 7 , 19 , 20 ].…”

Assessment of Commercial Real-Time PCR Assays for Detection of Malaria Infection in a Non-Endemic Setting

“…[26][27][28] In addition, some commercial LAMP methods for malaria diagnosis have been developed. [29][30][31] Nevertheless, contamination can be also present in LAMP methods 31 and independent amplification processes are needed for species identification.…”