Allam et al., Prim Health Care 2018, 8:3
DOI: 10.4172/2167-1079.1000305
Volume 8 • Issue 3 • 1000305
Prim Health Care, an open access journal
ISSN: 2167-1079
Open Access Research Article
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ISSN: 2167-1079
Primary Health Care: Open Access
*Corresponding author: Amal Farahat Allam, Department of Parasitology, Medical
Research Institute, Alexandria University, Alexandria, Egypt, Tel: 02034286496;
E-mail: amalalam2005@yahoo.com
Received: August 10, 2018; Accepted: September 20, 2018; Published:
September 27, 2018
Citation: Allam AF, Farag HF, Osman MM, Hagras NA, Ahmed MAR, et al. (2018)
Progress towards Schistosomiasis Elimination: Application of Sensitive Diagnostic
Techniques. Prim Health Care 8: 305. doi: 10.4172/2167-1079.1000305
Copyright: © 2018 Allam AF, et al. This is an open-access article distributed under
the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and
source are credited.
Keywords: Schistosoma mansoni; Kato-Katz; Circulating cathodic
antigen point of care cassette test (CCA-POC); SYBR green; Real-time
PCR
Introduction
Schistosomiasis is a chronic disease caused by infection with parasitic
worms of the genus Schistosoma. It is considered one of the neglected
diseases responsible for disabilities each year around the globe [1,2].
Approximately 240 million human individuals are infected globally and
about 700 million people are living at risk of this infection [3].
Schistosomiasis control has received support through global
alliances and partnerships. A cardinal step was taken by the WHO in
setting out a clear strategy for the scale up of preventive chemotherapy
and assistance to countries to appraise their future praziquantel
needs until 2020 and beyond. Its current strategy for the control of
schistosomiasis is the reduction of morbidity through regular treatment
with praziquantel of populations at risk [4,5]. Eforts to control
morbidity of the disease are being stepped up worldwide. In some
countries, there are existent prospects to turnover from schistosomiasis
control into transmission control and eventually elimination [6]. What
is more, elimination in selected areas by 2025 is now an aim [7,8].
In conditions where elimination of schistosomiasis is aimed at,
case detection may pose a problem as the commonly used methods
lack the necessary sensitivity to accurately determine the prevalence
of schistosomiasis or low infection intensity [9,10]. Active surveillance
should rely upon proper diagnosis, particularly in situations of low
intensity [9-11].
Kato-Katz is the method recommended for diagnosis of S.
mansoni infection by the WHO for its high specifcity, handiness and
cost efectiveness [12]. Te concern that Kato-Katz method misses S.
mansoni infection in a proportion of cases in regions of low prevalence
and intensity has a very important implication, principally when it is
used in monitoring the efectiveness of preventive chemotherapy [13].
Serodiagnostic assays designed for the detection of specifc anti-
schistosome antibodies and antigens have been developed over the
years [14,15]. However, the drawback intrinsic to antibodies assays is
the discrimination between active and old infections [15]. In addition,
blood collection is not easily applicable for feld studies in endemic
areas [14,15].
Te commercially available point of care urine Circulating Cathodic
Antigen (CCA-POC) has been shown to be a promising approach to
Progress towards Schistosomiasis Elimination: Application of Sensitive
Diagnostic Techniques
Amal Farahat Allam
1
*, Hoda Fahmy Farag
1
, Mervat Mostafa Osman
2
, Nancy Abd-elkader Hagras
2
, Mohamed Abdel Rahman Ahmed
3
, Adel
Zaki
4
, Rashad Abdul-Ghani
5
and Amel Youssef Shehab
1
1
Department of Parasitology, Medical Research Institute, Alexandria University, Alexandria, Egypt
2
Department of Medical Laboratory, Faculty of Applied Medical Sciences, Pharos University in Alexandria, Alexandria, Egypt
3
Department of Clinical Pathology, Military Medical Academy, Armed Forces Hospital, Alexandria, Egypt.
4
Department of Medical Statistics, Medical Research Institute, AlexandriaUniversity, Alexandria, Egypt
5
Department of Parasitology, Faculty of Medicine and Health Sciences, Sana’a University, Yemen
Abstract
Objective: Pursuing successful control programs aiming at schistosomiasis elimination, the diagnostic performance
of Kato-Katz, urine Circulating Cathodic Antigen (CCA) point of care rapid test and real-time PCR techniques were
compared for the detection of Schistosoma mansoni among school children with different infection intensities.
Methods: Stool and urine samples were collected from 110 school children after obtaining the consent of their
parents and school guardians. The study was conducted in Motobus village, Kafr El-Sheikh governorate, Egypt. The
collected stool samples were examined after Kato Katz (two slides, 41.7 mg each). Urine specimens were examined
for S. haematobium by fltration technique and were tested for S. mansoni by POC-CCA. For of real time PCR, part of
each stool sample was kept at -20°C until used.
Results: All the examined children were negative for S. haematobium. The performance of the three tests revealed
that examination of double Kato-Katz smears detected S. mansoni infection in 51% of school children, where most of
them had low infection intensity (64%). However, higher S. mansoni prevalence of 83% and 60% were diagnosed by
real-time PCR and CCA, respectively. It was also found that real-time PCR detected a higher proportion of S. mansoni
negative cases after Kato-Katz- compared to CCA (70% and 22%) respectively. Kato-Katz, CCA and real time PCR
showed similar results with moderate and heavy infection intensities. Increasing the number of cycles of real time PCR
to 40 cycles could detect the low infection intensity.
Conclusion: To move towards schistosomaisis elimination, real time PCR due to its great sensitivity is suitable
for established control programs to detect cases overlooked by Kato-Katz technique and CCA test. The adoption
of this technique can enhance the monitoring of Schistosomiasis mansoni control measures in pre-elimination or
elimination settings.