Validity of PCR Versus Coproscopic Examination for Diagnosing Infection with Schistosoma mansoni in a Low Intensity Endemic Area in Egypt

Bassiouny, Hassan; Eassa, Safaa; Hazzah, Walaa; El-Komy, Engy; Barakat, Rashida

doi:10.21608/jhiph.2018.19952

Validity of PCR Versus Coproscopic Examination for Diagnosing Infection with Schistosoma mansoni in a Low Intensity Endemic Area in Egypt

Document Type : Original Article

Authors

¹ Tropical Health Department (Parasitology Specialty), High Institute of Public Health, Alexandria University, Egypt

² Microbiology Department, High Institute of Public Health, Alexandria University, Egypt

³ Fellow of the Tropical Health Department (Parasitology Specialty), High Institute of Public Health, Alexandria University, Egypt

10.21608/jhiph.2018.19952

Abstract

Background: Egypt is a Schistosoma endemic country with localized foci of transmission. Although ongoing public health control programs could reduce infection rates, yet the situation evaluation necessitates a good diagnostic technique.
Objective(s) As the current parasitological methods lack efficiency, the aim of present study was to assess the validity of conventional polymerase chain reaction (PCR) versus coproscopic techniques as gold-standard to diagnose S. mansoni infection in a low intensity endemic area in Egypt.
Methods: A cross sectional study was used to examine faecal samples of 120 primary schoolchildren; 74 (61.7%) were males and 46 (38.3%) were females with mean age of 10.16±0.798 years (range: 9-12 years). Three fresh stool samples were collected on three consecutive days from each study subject and examined by formalin-ether concentration (FEC); three slides from one fecal sample of the first day. Ten slides from three fecal samples on three consecutive days were examined by Kato-Katz technique; 6 slides on the first day and 4 slides from 2^ndand 3^rd day samples, 2 each. Lastly, one sample of the fecal specimen of the 1^st day was tested by PCR.
Results: S. mansoni infection prevalence was 40.0 %, 69.2% and 80.8% by FEC, Kato-Katz, and PCR techniques, respectively. All infected cases were of low intensity infection (<100 epg). The overall geometric mean egg count (GMEC) was 13.35 and 33.34 epg stool by FEC and Kato-Katz techniques, respectively. The Kappa index (0.75) and diagnostic parameters showed a good diagnostic value of PCR as compared to copromicroscopic examination.
Conclusion: PCR demonstrated a good diagnostic performance for the detection of S. mansoni in low intensity endemic area versus coproscopic examination as gold-standard.

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