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Migratory flows and international travel are triggering an increase in imported cases of schistosomiasis in non-endemic countries. The present study aims to evaluate the effectiveness of the LAMP technique on patients' urine samples for the diagnosis of imported schistosomiasis in a non-endemic area in comparison to a commercial immunochromatographic test and microscopic examination of feces and urine. A prospective observational study was conducted in sub-Saharan migrants attending the Tropical Medicine Unit, Almería, Spain. For schistosomiasis diagnosis, serum samples were tested using an immunochromatographic test (Schistosoma ICT IgG-IgM). Stool and urine samples were examined by microcopy. Urine samples were evaluated by combining three LAMP assays for the specific detection of Schistosoma mansoni , S. haematobium , and for the genus Schistosoma . To evaluate the diagnostic accuracy, a latent class analysis (LCA) was performed. In total, 115 patients were included (92.2% male; median age: 28.3 years). Of these, 21 patients (18.3%) were diagnosed with schistosomiasis confirmed by microscopy, with S. haematobium being the most frequent species identified (18/115; 15.7%). The Schistosoma ICT IgG-IgM test result was 100% positive and Schistosoma-LAMP was 61.9% positive, reaching as high as 72.2% for S. haematobium . The sensitivity and specificity estimated by LCA, respectively, were: 92% and 76% for Schistosoma ICT IgG-IgM, 68% and 44% for Schistosoma-LAMP, and 46% and 97% for microscopy. In conclusion, the Schistosoma-LAMP technique presented a higher sensitivity than microscopy for the diagnosis of imported urinary schistosomiasis, which could improve the diagnosis of active infection, both in referral centers and in centers with limited experience or scarce resources and infrastructure.

Loiasis, caused by the filarial nematode Loa loa , is endemic in Central and West Africa. Loa loa has been associated with severe adverse reactions in high Loa -infected individuals receiving ivermectin during mass drug administration programs for the control of onchocerciasis and lymphatic filariasis. Diagnosis of loiasis still depends on microscopy in blood samples, but this is not effective for large-scale surveys. New diagnostics methods for loiasis are urgently needed. Previously, we developed a colorimetric high-sensitive and species-specific LAMP for Loa loa DNA detection. Here, we evaluate it in a set of 100 field-collected clinical samples stored as dried blood spots. In addition, Loa loa -LAMP was also evaluated in real-time testing and compared with microscopy and a specific PCR/nested PCR. A simple saponin/Chelex-based method was used to extract DNA. Colorimetric and real-time LAMP assays detected more samples with microscopy-confirmed Loa loa and Loa loa / Mansonella perstans mixed infections than PCR/nested-PCR. Samples with the highest Loa loa microfilariae counts were amplified faster in real-time LAMP assays. Our Loa loa -LAMP could be a promising molecular tool for the easy, rapid and accurate screening of patients for loiasis in endemic areas with low-resource settings. The real-time testing (feasible in a handheld device) could be very useful to rule out high-microfilariae loads in infected patients.

Detection of SARS-CoV-2 is routinely performed in naso/oropharyngeal swabs samples from patients via RT-qPCR. The RT-LAMP technology has also been used for viral RNA detection in respiratory specimens with both high sensitivity and specificity. Recently, we developed a novel RT-LAMP test for SARS-CoV-2 RNA detection in nasopharyngeal swab specimens (named, N15-RT-LAMP) that can be performed as a single-tube colorimetric method, in a real-time platform, and as dry-LAMP. To date, there has been very little success in detecting SARS-CoV-2 RNA in urine by RT-qPCR, and the information regarding urine viral excretion is still scarce and not comprehensive. Here, we tested our N15-RT-LAMP on the urine of 300 patients admitted to the Hospital of Salamanca, Spain with clinical suspicion of COVID-19, who had a nasopharyngeal swab RT-qPCR-positive ( n = 100), negative ( n = 100), and positive with disease recovery ( n = 100) result. The positive group was also tested by RT-qPCR for comparison to N15-RT-LAMP. Only a 4% positivity rate was found in the positive group via colorimetric N15-RT-LAMP and 2% via RT-qPCR. Our results are consistent with those obtained in other studies that the presence of SARS-CoV-2 RNA in urine is a very rare finding. The absence of SARS-CoV-2 RNA in urine in the recovered patients might suggest that the urinary route is very rarely used for viral particle clearance.

Schistosomiasis is a disease of great medical and veterinary importance in tropical and subtropical regions caused by different species of parasitic flatworms of the genus Schistosoma . The emergence of natural hybrids of schistosomes indicate the risk of possible infection to humans and their zoonotic potential, specifically for Schistosoma haematobium and S. bovis . Hybrid schistosomes have the potential to replace existing species, generate new resistances, pathologies and extending host ranges. Hybrids may also confuse the serological, molecular and parasitological diagnosis. Currently, LAMP technology based on detection of nucleic acids is used for detection of many agents, including schistosomes. Here, we evaluate our previously developed species-specific LAMP assays for S. haematobium , S. mansoni , S. bovis and also the genus-specific LAMP for the simultaneous detection of several Schistosoma species against both DNA from pure and, for the first time, S. haematobium x S. bovis hybrids. Proper operation was evaluated with DNA from hybrid schistosomes and with human urine samples artificially contaminated with parasites' DNA. LAMP was performed with and without prior DNA extraction. The genus-specific LAMP properly amplified pure Schistosoma species and different S. haematobium-S. bovis hybrids with different sensitivity. The Schistosoma spp.-LAMP method is potentially adaptable for field diagnosis and disease surveillance in schistosomiasis endemic areas where human infections by schistosome hybrids are increasingly common.

Human schistosomiasis is one of the most important parasitic diseases, causing around 250 million cases (mostly in Africa) and 280,000-500,000 deaths every year. Due to the limited resources and the far-removed nature of many endemic areas, the implementation of new, sensitive and specific diagnostic tools has had little success. This is particularly true for PCR-based molecular methods that require expensive equipment and trained personnel to be executed. Loop-mediated isothermal amplification (LAMP) along with other isothermal techniques appeared in the early 21st century as an alternative to those methods, overcoming some of the aforementioned limitations and achieving a more inexpensive diagnostic. However, to this date, neither LAMP nor any other isothermal technique have signified a meaningful change in the way schistosomiasis diagnosis is routinely performed. Here, we present the recent developments in LAMP-based schistosomiasis diagnosis. We expose the main advantages and disadvantages of LAMP technology over PCR and other classical diagnostic methods focusing in various research approaches on intermediate hosts, animal models and patients. We also examine its potential clinical application in post-therapy monitoring, as well as its usefulness as a point-of-care test.