Evaluating a point-of-care circulating cathodic antigen test (POC-CCA) to detect Schistosoma mansoni infections in a low endemic area in north-eastern Brazil

Q: What diagnostic methods were compared in this study for Schistosoma mansoni?

The study compared a urine point-of-care circulating cathodic antigen test (POC-CCA) with Kato-Katz stool microscopy for egg detection, and SWAP-ELISA for specific antibodies against adult worms in serum at baseline.

Q: How did POC-CCA performance differ from Kato-Katz in a low endemic area?

POC-CCA identified more positive cases than Kato-Katz, especially when trace readings were considered positive (11.6% vs 1.6%). Agreement between POC-CCA and Kato-Katz based on limited POC-CCA readings was poor (Kappa indexes < 0.20).

Q: What were the follow-up findings after praziquantel treatment?

Most prior POC-CCA positives became negative by the third week and reached 100% negativity by the sixth week. At one year, nearly all were negative with only trace results in one person; at two years, all were egg-negative by Kato-Katz, while POC-CCA still showed traces in a small proportion.

Sep 26, 2026

Uploaded by jayni

Schistosomiasis remains a public health issue in Brazil, where the widely used Kato-Katz stool method shows limited sensitivity in low-prevalence settings. A urine point-of-care circulating cathodic antigen test (POC-CCA) was evaluated in Bananeiras, Ceara, comparing baseline results with Kato-Katz and SWAP-ELISA, then monitoring one and two years post-treatment using urine strips at 3–6 weeks. POC-CCA detected substantially more positives when trace readings were treated as positive, with poor agreement with Kato-Katz (Kappa < 0.20).

LanguageEnglish

CategoryHealthcare

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Pages7

Reading Time18 min

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Introduction

Diagnostic limitations of Kato-Katz in low endemicity

Rationale for antigen and antibody based approaches

Circulating cathodic antigen (CCA) lateral-flow urine testing

Acta Tropica 182 (2018) 264–270 Contents lists available at ScienceDirect Acta Tropica journal [homepage:](homepage: www.elsevier.com/locate/actatropica)[ www.elsevier.com/locate/actatropica](homepage: www.elsevier.com/locate/actatropica) Evaluating a point-of-care circulating cathodic antigen test (POC-CCA) to detect Schistosoma mansoni infections in a low endemic area in north-eastern Brazil Fernando Schemelzer Moraes Bezerraa,⁎, Joames Kauﬃmann Freitas Leala, Mariana Silva Sousaa, Marta Cristhiany Cunha Pinheiroa, Alberto Novaes Ramos Jr.a, Vanessa Silva-Moraesb, Naftale Katzb a Parasitology and Mollusks Biology Research Laboratory, Universidade Federal do Ceará, Rua Capitão Francisco Pedro 1210, Fortaleza, Ceará, 60.430-272, Brazil b Laboratory of Schistosomiasis, Instituto René Rachou, Fundação Oswaldo Cruz (Fiocruz), Avenida Augusto de Lima 1715, Belo Horizonte, Minas Gerais, 30190-002, Brazil A R T I C L E I N F O Keywords: Schistosomiasis Diagnosis POC-CCA Kato-Katz Low endemicity setting Brazil A B S T R A C T Schistosomiasis is still a public health problem in Brazil. The Kato-Katz test is the most frequently used diagnostic method for Schistosoma mansoni infection. However, it lacks sensitivity in areas of low prevalence. We have assessed the positivity rate of S. mansoni infection in Bananeiras, a village on Capistrano, Ceara, Brazil by performing a point-of-care test in urine to determine the circulating cathodic antigens (POC-CCA), and we compared the ﬁndings with those of the Kato-Katz technique for egg detection in stool and an enzyme-linked immunosorbent assay for speciﬁc antibodies against adult worms (SWAP-ELISA) in serum before treatment (baseline). Additionally, the POC-CCA and Kato-Katz test results were compared at one and two years posttreatment, and only POC-CCA strips were utilised for follow-up testing on urine samples at 3–6 weeks. Only one sample of stool and urine was collected per event. Overall, 258 individuals were investigated at the baseline. The POC-CCA test detected 10 (3.9%) positive cases; however, this amount increased to 30 (11.6%) when considering trace readings as positive (t + ), whereas the Kato-Katz method found only 4 (1.6%) positive cases and the SWAP-ELISA detected 105 (40.7%) positive cases. The consistency observed between a single POC-CCA (t + ) or (t-) and the Kato-Katz (three slides) was poor (Kappa indexes < 0.20). The highest positivity rate as determined by CCA and Kato-Katz was found in adults. At the baseline, a praziquantel treatment was administered to all individuals regardless of their infection status. According to the POC-CCA test, 93% of the previous positive cases became negative by the third week after the treatment; this rate reached 100% at the sixth week assessment. The follow-up showed that of the 175 individuals evaluated at one year post-treatment, only one (0.6%) showed ‘trace’ results, and all the individuals were negative for eggs in the stool. At two years, all 185 examined individuals were negative by the Kato-Katz method, and 11 (5.9%) presented traces by POCCCA. Our results indicate that a single POC-CCA test reveals a signiﬁcantly higher number of positive cases than the Kato-Katz technique for diagnosing S. mansoni in a low endemic setting, when trace results are considered as positive cases. Nevertheless, the true signiﬁcance of the trace is not clear. These ﬁndings reinforce the need to associate diﬀerent tools for improved schistosomiasis diagnosis in individuals with low parasite burdens. 1. Introduction According to data obtained by the national prevalence survey (2010–2015), an estimated 1% positive rate of Schistosoma mansoni was found in Brazil, where schistosomiasis remains a signiﬁcant public health problem (Katz et al., 2017). The parasitological detection of S. mansoni by Kato-Katz faecal microscopy is used extensively for diagnosis due to its practicability, eﬃcacy, and low cost. However, this method ha

FAQs

What diagnostic methods were compared in this study for Schistosoma mansoni?

The study compared a urine point-of-care circulating cathodic antigen test (POC-CCA) with Kato-Katz stool microscopy for egg detection, and SWAP-ELISA for specific antibodies against adult worms in serum at baseline.

How did POC-CCA performance differ from Kato-Katz in a low endemic area?

POC-CCA identified more positive cases than Kato-Katz, especially when trace readings were considered positive (11.6% vs 1.6%). Agreement between POC-CCA and Kato-Katz based on limited POC-CCA readings was poor (Kappa indexes < 0.20).

What were the follow-up findings after praziquantel treatment?

Most prior POC-CCA positives became negative by the third week and reached 100% negativity by the sixth week. At one year, nearly all were negative with only trace results in one person; at two years, all were egg-negative by Kato-Katz, while POC-CCA still showed traces in a small proportion.

Sep 26, 2026

Uploaded by jayni