The rapid-heat LAMPellet method: A potential diagnostic method for human urogenital schistosomiasis

Background urogenital schistosomiasis due to schistosoma haematobium is a serious underestimated public health problem affecting 112 million people - particularly in sub-saharan africa. microscopic examination of urine samples to detect parasite eggs still remains as definitive diagnosis. this work was focussed on developing a novel loop-mediated isothermal amplification (lamp) assay for detection of s. haematobium dna in human urine samples as a high-throughput,simple,accurate and affordable diagnostic tool to use in diagnosis of urogenital schistosomiasis. methodology/principal findings a lamp assay targeting a species specific sequence of s. haematobium ribosomal intergenic spacer was designed. the effectiveness of our lamp was assessed in a number of patients´ urine samples with microscopy confirmed s. haematobium infection. for potentially large-scale application in field conditions,different dna extraction methods,including a commercial kit,a modified naoh extraction method and a rapid heating method were tested using small volumes of urine fractions (whole urine,supernatants and pellets). the heating of pellets from clinical samples was the most efficient method to obtain good-quality dna detectable by lamp. the detection limit of our lamp was 1 fg/μl of s. haematobium dna in urine samples. when testing all patients´ urine samples included in our study,diagnostic parameters for sensitivity and specificity were calculated for lamp assay,100% sensitivity (95% ci: 81.32%-100%) and 86.67% specificity (95% ci: 75.40%-94.05%),and also for microscopy detection of eggs in urine samples,69.23% sensitivity (95% ci: 48.21% -85.63%) and 100% specificity (95% ci: 93.08%-100%). conclusions/significance we have developed and evaluated,for the first time,a lamp assay for detection of s. haematobium dna in heated pellets from patients´ urine samples using no complicated requirement procedure for dna extraction. the procedure has been named the rapid-heat lampellet method and has the potential to be developed further as a field diagnostic tool for use in urogenital schistosomiasis-endemic areas. © 2015 gandasegui et al.