Performance of a real-time PCR approach for diagnosing Schistosoma haematobium infections of different intensity in urine samples from Zanzibar  

作　　者：Dominique Keller Julian Rothen Jean-Pierre Dangy Corina Saner Claudia Daubenberger Fiona Allan Shaali M.Ame Said M.Ali Fatma Kabole Jan Hattendorf David Rollinson Ralf Seyfarth Stefanie Knopp 

机构地区：[1]Biolytix AG,Benkenstrasse 254,4108 Witterswil,Switzerland [2]Swiss Tropical and Public Health Institute,Socinstrasse 57,4002 Basel,Switzerland [3]University of Basel,Petersplatz 1,4001 Basel,Switzerland [4]Wolfson Wellcome Biomedical Laboratories,Department of Life Sciences,Natural History Museum,Cromwell Road,London SW75BD,UK [5]Public Health Laboratory Ivo de Carneri,P.O.Box 122,Chake-Chake,Pemba,United Republic of Tanzania [6]Neglected Diseases Programme,Ministry of Health,P.O.Box 236,Zanzibar Town,Unguja,United Republic of Tanzania

出　　处：《Infectious Diseases of Poverty》2020年第5期22-34,共13页贫困所致传染病（英文）

基　　金：This study received financial support from Innosuisse(project 18553.2 PFLS-LS);from the University of Georgia Research Foundation Inc.,which is funded by the Bill&Melinda Gates Foundation for the Schistosomiasis Consortium for Operational Research and Evaluation(SCORE)projects(prime award no.50816,sub-award no.RR374–053/4893206);SK received financial support by sub-award no.RR374–053/4893196 and via direct grants from the Bill&Melinda Gates Foundation(Investment IDs:OPP1191423 and OPP1198086);FA received financial support from the Wellcome Trust(SCAN Project 104958/Z/14/Z).

摘　　要：Background:Efforts to control and eliminate schistosomiasis have accelerated over the past decade.As parasite burden,associated morbidity and egg excretion decrease,diagnosis with standard parasitological methods becomes harder.We assessed the robustness and performance of a real-time PCR(qPCR)approach in comparison with urine filtration microscopy and reagent strip testing for the diagnosis of Schistosoma haematobium infections of different intensities.Methods:The robustness of DNA isolation and qPCR was validated in eight laboratories from Europe and Africa.Subsequently,792 urine samples collected during cross-sectional surveys of the Zanzibar Elimination of Schistosomiasis Transmission(ZEST)project in 2012-2017 were examined with qPCR in 2018.Diagnostic sensitivity of the qPCR was calculated at different infection intensity categories,using urine filtration microscopy as reference test.Spearman's rank correlation between Ct-values and S.haematobium egg counts was assessed and Ct-value percentiles for infection intensity categories determined.Results:S.haematobium Dra1 DNA-positive samples were identified correctly in all eight laboratories.Examination of urine samples from Zanzibar revealed Dra1 DNA in 26.8%(212/792)by qPCR,S.haematobium eggs in 13.3%(105/792)by urine filtration,and microhaematuria in 13.8%(109/792)by reagent strips.Sensitivity of the qPCR increased with augmenting egg counts:80.6%(29/36)for counts between 1 and 4 eggs,83.3%(15/18)for counts between 5 and 9 eggs,100%(23/23)for counts between 10 and 49 eggs,and 96.4%(27/28)for counts of 50+eggs.There was a significant negative correlation between Ct-values and egg counts(Spearman's rho=-0.49,P<0.001).Seventy-five percent of the Ct-values were≥33 in the egg-negative category,<31 in the light intensity category,and<24 in the heavy intensity category.Conclusions:While the sensitiivity of the qPCR was^80%for very light intensity infections(egg counts<10),in general,the Dra1 based qPCR assay detected twice as many S.haematobium infections compared

关 键 词：Control Diagnosis DRA 1 Elimination Microhaematuria Real-time PCR SCHISTOSOMA haematobium Surveillance URINE filtration ZANZIBAR 

分 类 号：R532.21[医药卫生—内科学] R440[医药卫生—临床医学]