Detection of low-intensity Schistosoma mansoni infection by Percoll sedimentation and real-time PCR techniques in a low-endemicity Egyptian setting

作者：Allam Amal F^*; Farag Hoda F; Zaki Adel; Kader Ola A; Abdul Ghani Rashad; Shehab Amel Y

来源：Tropical Medicine and International Health, 2015, 20(5): 658-664.

DOI：10.1111/tmi.12470

• Schistosoma mansoni
• Kato-Katz
• percoll
• SYBR Green
• real-time PCR

ObjectiveTo 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.
MethodsStool samples of 824 primary schoolchildren were examined by Kato-Katz technique (three slides of 41.7mg 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 degrees C and further processed by SYBR Green PCR.
ResultsPrevalence 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.
ConclusionPercoll sedimentation and SYBR Green PCR proved useful in detecting low-intensity S.mansoni infections in low-endemicity areas in Egypt.

• 出版日期2015-5