Vinkeles Melchers N.V.S., van Dam G.J., Shaproski D., Kahama A.I., Brienen E.A.T., Vennervald B.J., van Lieshout L.
Leiden University Medical Centre, Department of Parasitology, Centre of Infectious Diseases, Leiden, Netherlands; Division of Vector Borne Diseases, Ministry of Health, Nairobi, Kenya; Section for Parasitology and Aquatic Diseases, University of Copenhagen, Copenhagen, Denmark; Novartis Animal Health Canada Inc. (Aqua Health Victoria Site), Victoria, PE, Canada
Vinkeles Melchers, N.V.S., Leiden University Medical Centre, Department of Parasitology, Centre of Infectious Diseases, Leiden, Netherlands; van Dam, G.J., Leiden University Medical Centre, Department of Parasitology, Centre of Infectious Diseases, Leiden, Netherlands; Shaproski, D., Leiden University Medical Centre, Department of Parasitology, Centre of Infectious Diseases, Leiden, Netherlands; Kahama, A.I., Division of Vector Borne Diseases, Ministry of Health, Nairobi, Kenya, Novartis Animal Health Canada Inc. (Aqua Health Victoria Site), Victoria, PE, Canada; Brienen, E.A.T., Leiden University Medical Centre, Department of Parasitology, Centre of Infectious Diseases, Leiden, Netherlands; Vennervald, B.J., Section for Parasitology and Aquatic Diseases, University of Copenhagen, Copenhagen, Denmark; van Lieshout, L., Leiden University Medical Centre, Department of Parasitology, Centre of Infectious Diseases, Leiden, Netherlands
Background:In an effort to enhance accuracy of diagnosis of Schistosoma haematobium, this study explores day-to-day variability and diagnostic performance of real-time PCR for detection and quantification of Schistosoma DNA compared to other diagnostic tools in an endemic area before and after treatment.Methodology:Previously collected urine samples (N = 390) from 114 preselected proven parasitological and/or clinical S. haematobium positive Kenyan schoolchildren were analyzed by a Schistosoma internal transcribed spacer-based real-time PCR after 14 years of storage. Pre-treatment day-to-day fluctuations of PCR and microscopy over three consecutive days were measured for 24 children using intra-class correlation coefficient. A combined 'gold standard' (PCR and/or microscopy positive) was used to measure sensitivity and negative predictive value (NPV) of several diagnostic tools at baseline, two and 18 months post-treatment with praziquantel.Principal Findings:All 24 repeatedly tested children were PCR-positive over three days with little daily variation in median Ct-values, while 83.3% were found to be egg-positive for S. haematobium at day 1 and 75.0% at day 2 and 3 pre-treatment, signifying daily fluctuations in microscopy diagnosis. Of all 114 preselected schoolchildren, repeated microscopic measurements were required to detect 96.5% versus 100% of positive pre-treatment cases by single PCR. At two months post-treatment, microscopy and PCR detected 22.8% versus 69.3% positive children, respectively. Based on the 'gold standard', PCR showed high sensitivity (>92%) as compared to >31% sensitivity for microscopy, both pre- and post-treatment.Conclusions/Significance:Detection and quantification of Schistosoma DNA in urine by real-time PCR was shown to be a powerful and specific diagnostic tool for detection of S. haematobium infections, with less day-to-day variation and higher sensitivity compared to microscopy. The superior performance of PCR before, and two and 18 months post-treatment provides a compelling argument for PCR as an accurate and reproducible tool for monitoring treatment efficacy. © 2014 Vinkeles Melchers et al.
antigen; circulating soluble egg antigen; praziquantel; unclassified drug; article; child; data analysis; diagnostic test accuracy study; enzyme linked immunosorbent assay; female; follow up; hematuria; human; major clinical study; male; predictive value; real time polymerase chain reaction; Schistosoma; schistosomiasis haematobia; sensitivity and specificity; Adolescent; Animals; Anthelmintics; Child; DNA, Ribosomal Spacer; Drug Monitoring; Female; Humans; Kenya; Male; Microscopy; Parasitology; Praziquantel; Predictive Value of Tests; Real-Time Polymerase Chain Reaction; Retrospective Studies; Schistosoma haematobium; Schistosomiasis haematobia; Sensitivity and Specificity; Urine