Background: Chile is one of the South American countries certified as malaria-free since 1945. However, the recent increase of imported malaria cases and the presence of the vector Anopheles pseudopunctipennis in previously endemic areas in Chile require an active malaria surveillance programme. Methods: Specimens from 268 suspected malaria cases-all imported-collected between 2015 and 2018 at the Public Health Institute of Chile (ISP), were diagnosed by microscopy and positive cases were included for epidemiological analysis. A photo-induced electron transfer fluorogenic primer real-time PCR (PET-PCR) was used to confirm the presence of malaria parasites in available blood samples. Sanger sequencing of drug resistance molecular markers (pfk13, pfcrt and pfmdr1) and microsatellite (MS) analysis were performed in confirmed Plasmodium falciparum samples and results were related to origin of infection. Results: Out of the 268 suspected cases, 65 were Plasmodium spp. positive by microscopy. A total of 63% of the malaria patients were male and 37% were female; 43/65 of the patients acquired infections in South American endemic countries. Species confirmation of available blood samples by PET-PCR revealed that 15 samples were positive for P. falciparum, 27 for Plasmodium vivax and 4 were mixed infections. The P. falciparum samples sequenced contained four mutant pfcrt genotypes (CVMNT, CVMET, CVIET and SVMNT) and three mutant pfmdr1 genotypes (Y184F/ S1034C/N1042D/D1246Y, Y184F/N1042D/D1246Y and Y184F). MS analysis confirmed that all P. falciparum samples presented different haplotypes according to the suspected country of origin. Four patients with P. vivax infection returned to the health facilities due to relapses. Conclusion: The timely detection of polymorphisms associated with drug resistance will contribute to understanding if current drug policies in the country are appropriate for treatment of imported malaria cases and provide information about the most frequent resistant genotypes entering Chile.

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.