Application of DNA-based diagnostics in detection of schistosomal DNA in early infection and after drug treatment

This study compared loop-mediated isothermal amplification (LAMP) with conventional PCR as DNA-based diagnostic techniques for the early detection of schistosomal DNA and the evaluation of chemotherapy. The results showed that both PCR and LAMP assays targeting a 301 base pair (bp) sequence of the highly repetitive retrotransposon, SjR2, amplified DNA from schistosomes but were unable to distinguish between schistosome species. LAMP and conventional PCR were shown to amplify the target sequence of the SjR2-pCR2.1 recombinant plasmid template with limits of detection of 10-4 ng and 10-2 ng, respectively, thus demonstrating the superior sensitivity of the LAMP method. Schistosoma japonicum DNA was detected in all serum samples obtained from the three experimental groups at 1 week post-infection by LAMP assay, while the rate of detection by conventional PCR ranged from 50% to 66%. The potential application of PCR and LAMP assays for the evaluation of artesunate and praziquantel chemotherapy was investigated. PCR was shown to be less sensitive for detection of schistosomal DNA in drug-treated rabbit sera than the LAMP method.The data presented here indicate that LAMP is suitable for the detection of early infection in the groups primarily infected with Schistosoma japonicum, such as migrants, travellers, military personnel and the younger age groups. However, it is less suitable for evaluation of the efficacy of chemotherapy in the early stages because of its high sensitivity.Schistosomiasis remains one of the most common parasitic diseases, afflicting more than 200 million people worldwide [1]. In China, Schistosoma japonicum is the only causative species of schistosomiasis, which leads to hepatic periportal fibrosis and portal hypertension due to the deposition of Schistosoma japonicum eggs in tissues[2]. The morbidity associated with schistosomiasis has been successfully controlled in China through chemotherapy. However, it is difficult to eliminate this disease comp