{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T23:38:59Z","timestamp":1790293139169,"version":"4.1.0"},"reference-count":51,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,3,16]],"date-time":"2021-03-16T00:00:00Z","timestamp":1615852800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:p>The laboratorial diagnosis of the intestinal schistosomiasis is always performed using Kato-Katz technique. However, this technique presents low sensitivity for diagnosis of individuals with low parasite burden, which constitutes the majority in low endemicity Brazilian locations for the disease. The objective of this study was developed and to validate a real-time PCR assay (qPCR) targeting 121 bp sequence to detect <jats:italic>Schistosoma<\/jats:italic> spp. DNA for the diagnosis of intestinal schistosomiasis and a sequence of the human \u03b2-actin gene as internal control. Firstly, the qPCR was standardized and next it was evaluated for diagnosis and cure assessment of intestinal schistosomiasis in the resident individuals in Tabuas and Estreito de Miralta, two locations in Brazil endemic for intestinal schistosomiasis. The qPCR assay results were compared with those of the Kato-Katz (KK) test, examining 2 or 24 slides, Saline Gradient (SG) and \u201creference test\u201d (24 KK slides + SG). The cure assessment was measured by these diagnostic techniques at 30, 90, and 180 days post-treatment. In Tabuas, the positivity rates obtained by the qPCR was 30.4% (45\/148) and by \u201creference test\u201d was of 31.0% (46\/148), with no statistical difference (p = 0.91). The presumed cure rates at 30, 90, and 180 days post-treatment were 100, 94.4, and 78.4% by the analysis of 24 KK slides, 100, 94.4, and 78.4% by the SG, and 100, 83.3, and 62.1% by the qPCR assay. In Estreito de Miralta, the positivity obtained by qPCR was 18.3% (26\/142) and with \u201creference test\u201d was 24.6% (35\/142), with no statistical difference (p = 0.20). The presumed cure rates were 93.3, 96.9, and 96.5% by the KK, 93.3, 96.9, and 100% by the SG, and 93.3, 93.9, and 96.5% by the qPCR at 30, 90, and 180 days post-treatment, respectively. This study showed that the diagnostic techniques presented different performance in the populations from the two districts (Tabuas and Estreito de Miralta) and reinforces the need of combining techniques to improve diagnosis accuracy, increasing the detection of individuals with low parasite burden. This combination of techniques consists an important strategy for controlling the disease transmission.<\/jats:p>","DOI":"10.3389\/fimmu.2020.620417","type":"journal-article","created":{"date-parts":[[2021,3,16]],"date-time":"2021-03-16T05:26:16Z","timestamp":1615872376000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":19,"title":["A Real-Time PCR Assay for the Diagnosis of Intestinal Schistosomiasis and Cure Assessment After the Treatment  of Individuals With Low Parasite Burden"],"prefix":"10.3389","volume":"11","author":[{"given":"Liliane Maria Vidal","family":"Siqueira","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carolina","family":"Senra","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u00c1ureo Almeida","family":"de Oliveira","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nidia Francisca de Figueiredo","family":"Carneiro","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luciana In\u00e1cia","family":"Gomes","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana","family":"Rabello","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paulo Marcos Zech","family":"Coelho","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Edward","family":"Oliveira","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2021,3,16]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"e180347","DOI":"10.1590\/0074-02760180347","article-title":"The cost of a disease targeted for elimination in Brazil: the case of schistosomiasis mansoni","author":"Nascimento","year":"2019","journal-title":"Mem Inst Oswaldo Cruz"},{"key":"B2","unstructured":"KatzN\n          Inquerito Nacional de Preval\u00eancia da Esquistossomose mansoni e Geo-helmintoses2018"},{"key":"B3","first-page":"397","article-title":"A simple device for quantitative stools thrick smear technique in schistosomiasis mansoni","volume":"14","author":"Katz","year":"1972","journal-title":"Rev Inst Med Trop S\u00e3o Paulo"},{"key":"B4","first-page":"86","volume-title":"The control of schistosomiasis. Second report of the WHO expert committee. Technical Report series 830","year":"1993"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182001007752","article-title":"Relative contribution of day-to-day and intra-specimen variation in faecal egg counts of\u00a0Schistosoma mansoni before and after treatment with praziquantel","volume":"122","author":"Utzinger","year":"2001","journal-title":"Parasitol"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1016\/j.actatropica.2004.06.011","article-title":"Variations in helminth faecal egg contours in Kato-Katz thick smears and their implications in assessing infection status with\u00a0Schistosoma mansoni","volume":"92","author":"Berhe","year":"2004","journal-title":"Acta Trop"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.4269\/ajtmh.2008.78.140","article-title":"A combined strategy to improve the control of\u00a0Schistosoma mansoni\u00a0in areas of low prevalence in Brazil","volume":"78","author":"Enk","year":"2008","journal-title":"Am J Trop Med Hyg"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1590\/S0074-02762011000700010","article-title":"Evaluation of two coproscopic techniques for the diagnosis of schistosomiasis in a low-transmission area in the state of Minas Gerais, Brazil","volume":"106","author":"Siqueira","year":"2011","journal-title":"Mem Inst Oswaldo Cruz"},{"key":"B9","doi-asserted-by":"publisher","first-page":"75","DOI":"10.1016\/j.pt.2012.11.003","article-title":"Schistosomiasis in areas of low endemicity: a new era in diagnosis","volume":"29","author":"Cavalcanti","year":"2013","journal-title":"Trends Parasitol"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1590\/0074-0276130202","article-title":"A conventional polymerase chain reaction-based method for the diagnosis of human schistosomiasis in stool samples from individuals in a low-endemicity area","volume":"108","author":"Carneiro","year":"2013","journal-title":"Mem Inst Oswaldo Cruz"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0003139","article-title":"Sensitivity and specificity of multiple Kato-Katz thick smears and a circulating cathodic antigen test for\u00a0Schistosoma mansoni\u00a0diagnosis pre and post-repeated-praziquantel treatment","volume":"8","author":"Lamberton","year":"2014","journal-title":"PloS Negl Trop Dis"},{"key":"B12","doi-asserted-by":"publisher","first-page":"2","DOI":"10.1016\/j.mcp.2016.12.003","article-title":"Serological approaches for the diagnosis of schistosomiasis: A review","volume":"31","author":"Hinz","year":"2017","journal-title":"Mol Cell Probes"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.4269\/ajtmh.12-0639","article-title":"A five-country evaluation of a point-of-care circulating cathodic antigen urine assay for the prevalence of Schistosoma mansoni","volume":"88","author":"Colley","year":"2013","journal-title":"Am J Trop Med Hyg"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0001384","article-title":"Accuracy of urine circulating cathodic antigen (CCA) test for Schistosoma mansoni diagnosis in different settings of Cote d\u2019Ivoire","volume":"5","author":"Coulibaly","year":"2011","journal-title":"PloS Negl Trop Dis"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0001758","article-title":"Evaluation of circulating cathodic antigen (CCA) urine-tests for diagnosis of Schistosoma mansoni infection in Cameroon","volume":"6","author":"Tchuent\u00e9","year":"2012","journal-title":"PloS Negl Trop Dis"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.4269\/ajtmh.1998.59.872","article-title":"A polymerase chain reaction assay for detecting snails infected with bilharzia parasites (Schistosoma mansoni) from very early prepatency","volume":"59","author":"Hamburger","year":"1998","journal-title":"Am J Trop Med Hyg"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.4269\/ajtmh.2003.68.652","article-title":"Comparison of a polymerase chain reaction and the Kato-Katz technique for diagnosing infection with Schistosoma mansoni","volume":"68","author":"Pontes","year":"2003","journal-title":"Am J Trop Med Hyg"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1590\/S0074-02762009000800021","article-title":"Further evaluation of an updated PCR assay for the detection of Schistosoma mansoni DNA in human stool samples","volume":"104","author":"Gomes","year":"2009","journal-title":"Mem Inst Oswaldo Cruz"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0000664","article-title":"Development and evaluation of a sensitive PCR-ELISA system for detection of Schistosoma infection in feces","volume":"4","author":"Gomes","year":"2010","journal-title":"PloS Negl Trop Dis"},{"key":"B20","doi-asserted-by":"publisher","first-page":"455","DOI":"10.1186\/s13104-018-3571-7","article-title":"Development of a laboratorial platform for diagnosis of schistosomiasis mansoni by PCR-ELISA","volume":"11","author":"Senra","year":"2018","journal-title":"BMC Res Notes"},{"key":"B21","doi-asserted-by":"publisher","first-page":"558","DOI":"10.1186\/s12879-014-0558-4","article-title":"Evaluation of real-time PCR assay to detect Schistosoma mansoni infections in a low endemic setting","volume":"14","author":"Esp\u00edrito-Santo","year":"2014","journal-title":"BMC Infect Dis"},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.1016\/j.molbiopara.2008.04.003","article-title":"Detection of schistosomes polymerase chain reaction amplified DNA by oligochromatographic dipstick","volume":"160","author":"Akinwale","year":"2008","journal-title":"Mol Biochem Parasitol"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0000422","article-title":"Diagnosing schistosomiasis by detection of cell-free parasite DNA in human plasma","volume":"3","author":"Wichmann","year":"2009","journal-title":"PloS Negl Trop Dis"},{"key":"B24","doi-asserted-by":"publisher","first-page":"115","DOI":"10.1186\/1756-0500-3-115","article-title":"A salting out and resin procedure for extracting Schistosoma mansoni DNA from human urine samples","volume":"3","author":"Enk","year":"2010","journal-title":"BMC Res Notes"},{"key":"B25","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0038947","article-title":"Diagnostic accuracy and applicability of a PCR system for the detection of Schistosoma mansoni DNA in human urine samples from an endemic area","volume":"7","author":"Enk","year":"2012","journal-title":"PloS One"},{"key":"B26","doi-asserted-by":"publisher","DOI":"10.1385\/1-59259-192-2:365","article-title":"Primer3 on the WWW for general users and for biologist programmers","volume":"132","author":"Rozen","year":"2000","journal-title":"Methods Mol Biol"},{"key":"B27","doi-asserted-by":"publisher","first-page":"5","DOI":"10.1007\/978-1-4939-0733-5_2","article-title":"Minimum information necessary for quantitative real-time PCR experiments","volume":"1160","author":"Johnson","year":"2014","journal-title":"Methods Mol Biol"},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.1590\/S0074-02762009000500010","article-title":"Use of a saline gradient for the diagnosis of schistosomiasis","volume":"104","author":"Coelho","year":"2009","journal-title":"Mem Inst Oswaldo Cruz"},{"key":"B29","unstructured":"DeanAG\n            SullivanKM\n            SoeMM\n          OpenEpi: Open Source Epidemiologic Statistics for Public Health"},{"key":"B30","volume-title":"Statistical concepts and methods","author":"Bhattacharyya","year":"1977"},{"key":"B31","doi-asserted-by":"publisher","DOI":"10.2307\/2529786","article-title":"An application of hierarchical kappa-type statistics in the assessment of majority agreement among multiple observers","volume":"33","author":"Landis","year":"1977","journal-title":"Biometrics"},{"key":"B32","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182006000898","article-title":"A new PCR-based approach for the specific amplification of DNA from different Schistosoma species applicable to human urine samples","volume":"133","author":"Sandoval","year":"2006","journal-title":"Parasitol"},{"key":"B33","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182018001361","article-title":"Developing a real-time PCR assay based on multiplex high-resolution melt curve analysis: a pilot study in detection and discrimination of soil-transmitted helminth and schistosome species","volume":"145","author":"Cunningham","year":"2018","journal-title":"Parasitology"},{"key":"B34","doi-asserted-by":"publisher","DOI":"10.1590\/S0074-02762006000900021","article-title":"Development of a real time polymerase chain reaction for quantitation of Schistosoma mansoni DNA","volume":"101","author":"Gomes","year":"2006","journal-title":"Mem Inst Oswaldo Cruz"},{"key":"B35","doi-asserted-by":"publisher","DOI":"10.4269\/ajtmh.2002.66.157","article-title":"Detection by polymerase chain reaction of Schistosoma mansoni DNA in human serum and feces","volume":"66","author":"Pontes","year":"2002","journal-title":"Am J Trop Med Hyg"},{"key":"B36","doi-asserted-by":"publisher","first-page":"1267826","DOI":"10.1155\/2018\/126826","article-title":"Development and evaluation of a loop-mediated isothermal amplification assay for diagnosis of Schistosoma mansoni infection in faecal samples","volume":"2018","author":"Mwangi","year":"2018","journal-title":"J Parasitol Res"},{"key":"B37","doi-asserted-by":"publisher","DOI":"10.1017\/S003118202000089X","article-title":"Accuracy of real-time polymerase chain reaction to detect Schistosoma mansoni-infected individuals from an endemic area with low parasite loads","volume":"147","author":"Magalh\u00e3es","year":"2020","journal-title":"Parasitology"},{"key":"B38","doi-asserted-by":"publisher","DOI":"10.1016\/j.trstmh.2007.10.011","article-title":"Multiplex real-time PCR for the detection and quantification of Schistosoma mansoni and S. haematobium infection in stool samples collected in northern Senegal","volume":"102","author":"Ten Hove","year":"2008","journal-title":"Trans R Soc Trop Med Hyg"},{"key":"B39","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0003959","article-title":"Is PCR the next reference standard for the diagnosis of Schistosoma in stool? A comparison with microscopy in Senegal and Kenya","volume":"9","author":"Meurs","year":"2015","journal-title":"PloS Negl Trop Dis"},{"key":"B40","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-3156.2012.03060.x","article-title":"Schistosoma real-time PCR as diagnostic tool for international trvellers and migrants","volume":"17","author":"Cnops","year":"2012","journal-title":"Trop Med Int Health"},{"key":"B41","doi-asserted-by":"publisher","first-page":"19","DOI":"10.1016\/j.mimet.2016.03.012","article-title":"Optimisation of a droplet digital PCR assay for the diagnosis of Schistosoma japonicum infection: A duplex approach with DNA binding dye chemistry","volume":"125","author":"Weerakoon","year":"2016","journal-title":"J Microbiol Methods"},{"key":"B42","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/jix521","article-title":"Droplet digital PCR diagnosis of human schistosomiasis: Parasite cell-free DNA detection in diverse clinical samples","volume":"216","author":"Weerakoon","year":"2017","journal-title":"J Infect Dis"},{"key":"B43","doi-asserted-by":"publisher","DOI":"10.4269\/ajtmh.1996.54.319","article-title":"Day-to-day egg count fluctuation in Schistosoma mansoni infection and its operational implications","volume":"54","author":"Engels","year":"1996","journal-title":"Am J Trop Med Hyg"},{"key":"B44","doi-asserted-by":"publisher","DOI":"10.1590\/0074-02760140375","article-title":"Evaluation of parasitological and molecular techniques for the diagnosis and assessment of cure of schistosomiasis mansoni in a low transmission area","volume":"110","author":"Siqueira","year":"2015","journal-title":"Mem Inst Oswaldo Cruz"},{"key":"B45","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0007711","article-title":"Real-time PCR for diagnosis of imported schistosomiasis","volume":"13","author":"Guegan","year":"2019","journal-title":"PloS Negl Trop Dis"},{"key":"B46","doi-asserted-by":"publisher","DOI":"10.1016\/S0169-4758(98)01315-5","article-title":"Is Schistosomicidal chemotherapy sub-curative? Implications for drug resistance","volume":"14","author":"Doenhoff","year":"1998","journal-title":"Parasitol Today"},{"key":"B47","doi-asserted-by":"publisher","first-page":"55","DOI":"10.1186\/1471-2334-13-55","article-title":"Prospective European-wide multicentre study on a blood based real-time PCR for the diagnosis of acute schistosomiasis","volume":"13","author":"Wichmann","year":"2013","journal-title":"BMC Infect Dis"},{"key":"B48","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1006817","article-title":"Simgle-sex schistosome infections of definitive hosts: implications for epidemiology and disease control in a changing word","volume":"14","author":"Lu","year":"2018","journal-title":"PloS Pathog"},{"key":"B49","doi-asserted-by":"publisher","DOI":"10.1590\/S0074-02762003000600025","article-title":"Schistosomiasis mansoni: follow-aup of control program based on parasitologic and serologic methods in a Brazilian community of low endemicity","volume":"98","author":"Burlandy-Soares","year":"2003","journal-title":"Mem Inst Oswaldo Cruz"},{"key":"B50","doi-asserted-by":"publisher","DOI":"10.1016\/j.ippara.2003","article-title":"Sex and stage related sensitivity of Schistosoma mansoni to in vivo and in vitro praziquantel treatment","volume":"34","author":"Pica-Mattoccia","year":"2004","journal-title":"Int J Parasitol"},{"key":"B51","doi-asserted-by":"publisher","first-page":"57","DOI":"10.1016\/j.molbiopara.2008","article-title":"Towards an understanding of the mechanism of action of praziquantel","volume":"164","author":"Aragon","year":"2009","journal-title":"Mol Biochem Parasitol"}],"container-title":["Frontiers in Immunology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2020.620417\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,3,16]],"date-time":"2021-03-16T05:26:23Z","timestamp":1615872383000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2020.620417\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,3,16]]},"references-count":51,"alternative-id":["10.3389\/fimmu.2020.620417"],"URL":"https:\/\/doi.org\/10.3389\/fimmu.2020.620417","relation":{},"ISSN":["1664-3224"],"issn-type":[{"value":"1664-3224","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,3,16]]},"article-number":"620417"}}