Real-time PCR and LAMP assays for the diagnosis of Schistosoma mansoni using urine samples: comparison of two DNA extraction methods

Currently, molecular tests on urine samples are being developed as complementary diagnostic tools for Schistosoma mansoni alongside parasitological methods. This study aimed to evaluate urine-based real-time PCR and LAMP using DNA extracted either with a commercial kit or by phenol–chloroform for detecting S. mansoni . Following ethical approval, stool samples were collected from 200 schoolchildren and examined using the Kato-Katz technique. A subset of 25 urine samples (20 S. mansoni positive and 5 negative by Kato-Katz) was tested by both real-time PCR and LAMP using the two DNA extraction methods. Kato-Katz diagnosed 36 positive cases, corresponding to a prevalence of 18%. Among them, 38.9%, 55.6% and 5.6% had light, moderate and heavy infections. The urine-based real-time PCR and LAMP commercial extraction kit detected all Kato–Katz positive cases, including those with low infection intensity. Moreover, real-time PCR and LAMP identified 4 and 2 cases, respectively, among Kato–Katz negatives. In contrast, real-time PCR and LAMP phenol/chloroform missed 2 and 3 Kato–Katz positives respectively, each of low infection intensity and LAMP detected one additional case negative by Kato–Katz. The highest sensitivity was observed in real-time PCR (100%) and the LAMP (92%) using the commercial kit, followed by Kato-Katz (83%) and the LAMP phenol/chloroform (75%). Conclusion Urine samples are an increasingly validated for S. mansoni diagnosis. The commercial kit outperformed phenol/chloroform for S. mansoni DNA extraction. Real-time PCR showed the highest performance and LAMP demonstrated a capability as a sensitive, specific, and rapid test suited for resource-limited settings. Although phenol/chloroform remains a cost-effective option, it requires further optimization.