Amal F. Allam
Alexandria University, Egypt
Title: Detection of low-intensity Schistosoma mansoni infection by Percoll sedimentation and real-time PCR techniques in a low-endemicity Egyptian setting
Biography
Biography: Amal F. Allam
Abstract
Objective To evaluate the performance of Percoll sedimentation and real-time polymerase chain reaction (PCR) for the detection of S. mansoni cases previously tested as negative by Kato–Katz technique in two low-endemic areas in Alexandria, Egypt, Abis 4 and 8 villages.
Methods: Stool samples of 824 primary schoolchildren were examined by Kato–Katz technique (three slides of 41.7 mg each). After obtaining the results of this survey, stool samples were recollected from a subset of 150 students, who gave negative results after Kato–Katz. These samples were microscopically examined after the concentration with Percoll technique. Part of the 150 negative stool samples and five positive samples (used as controls) were kept at _20 °C and further processed by SYBR Green PCR.
Results: Prevalence of S. mansoni infection as determined by three Kato–Katz thick smears was 1.82% (15 cases). Three more cases tested positive by Percoll sedimentation among the 150 samples that were negative by Kato–Katz. Specific amplification by SYBR Green PCR was noted in all positive controls and in three cases of Kato–Katz-negative samples, two of which were also positive by Percoll.
Conclusion: Percoll sedimentation and SYBR Green PCR proved useful in detecting low-intensity S. mansoni infections in low-endemicity areas in Egypt.
keywords Schistosoma mansoni, Kato–Katz, percoll, SYBR Green, real-time PCR