Author | Oliveira, Warllem Junio | |
Author | Magalhaes, Fernanda do Carmo | |
Author | Elias, Andressa Mariana Saldanha | |
Author | Castro, Vanessa Normandio de | |
Author | Favero, Vivian | |
Author | Lindholz, Catieli Gobetti | |
Author | Oliveira, Aureo Almeida | |
Author | Barbosa, Fernando Sergio | |
Author | Gil, Frederico | |
Author | Gomes, Maria Aparecida | |
Author | Teixeira, Carlos Graeff | |
Author | Enk, Martin Johannes | |
Author | Coelho, Paulo Marcos Zech | |
Author | Carneiro, Mariangela | |
Author | Correa, Deborah Aparecida Negrao | |
Author | Geiger, Stefan Michael | |
Access date | 2018-09-13T19:04:22Z | |
Available date | 2018-09-13T19:04:22Z | |
Document date | 2018 | |
Citation | OLIVEIRA, Warllem Junio et al. Evaluation of diagnostic methods for the detection of intestinal schistosomiasis in endemic areas with low parasite loads: Saline gradient, Helmintex, Kato-Katz and rapid urine test. PLoS Negl Trop Dis., v. 12, n. 2, e0006232, 2018 | pt_BR |
ISSN | 1935-2735 | pt_BR |
URI | https://www.arca.fiocruz.br/handle/icict/28775 | |
Language | eng | pt_BR |
Publisher | Public Library of Science | pt_BR |
Rights | open access | pt_BR |
Subject in Portuguese | Esquistossomose | pt_BR |
Title | Evaluation of diagnostic methods for the detection of intestinal schistosomiasis in endemic areas with low parasite loads: Saline gradient, Helmintex, Kato-Katz and rapid urine test | pt_BR |
Type | Article | pt_BR |
DOI | 10.1371/journal.pntd.0006232 | |
Abstract | BACKGROUND: In some tropical countries, such as Brazil, schistosomiasis control programs have led to a significant reduction in the prevalence and parasite burden of endemic populations. In this setting, the Kato-Katz technique, as the standard diagnostic method for the diagnosis of Schistosoma mansoni infections, which involves the analysis of two slides from one fecal sample, loses its sensitivity. As a result, a significant number of infected individuals are not detected. The objective of this study was to perform extensive parasitological testing of up to three fecal samples and include a rapid urine test (POC-CCA) in a moderate prevalence area in Northern Minas Gerais, Brazil, and evaluate the performance of each test separately and in combination.
METHODS AND FINDINGS: A total of 254 individuals were examined with variants of the standard Kato-Katz technique (up to18 Kato-Katz slides prepared from three fecal samples), a modified Helmintex (30 g of feces), the saline gradient (500 mg of feces), and the POC-CCA methods. We established a reference standard taking into consideration all the positive results in any of the parasitological exams. Evaluation of the parasite burden by two Kato-Katz slides confirmed that most of the individuals harbored a light infection. When additional slides and different parasitological methods were included, the estimated prevalence rose 2.3 times, from 20.4% to 45.9%. The best sensitivity was obtained with the Helmintex method (84%). All parasitological methods readily detected a high or moderate intensity of infection; however, all lost their high sensitivity in the case of low or very low intensity infections. The overall sensitivity of POC-CCA (64.9%) was similar to the six Kato-Katz slides from three fecal samples. However, POC-CCA showed low concordance (κ = 0.34) when compared with the reference standard.
CONCLUSIONS: The recommended Kato-Katz method largely underestimated the prevalence of S. mansoni infection. Because the best performance was achieved with a modified Helmintex method, this technique might serve as a more precise reference standard. An extended number of Kato-Katz slides in combination with other parasitological methods or with POC-CCA was able to detect more than 80% of egg-positive individuals; however, the rapid urine test (POC-CCA) produced a considerable percentage of false positive results. | pt_BR |
Affilliation | Universidade Federal de Minas Gerais. Instituto de Ciências Biologicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil | pt_BR |
Affilliation | Universidade Federal de Minas Gerais. Instituto de Ciências Biologicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil | pt_BR |
Affilliation | Universidade Federal de Minas Gerais. Instituto de Ciências Biologicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil | pt_BR |
Affilliation | Universidade Federal de Minas Gerais. Instituto de Ciências Biologicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil | pt_BR |
Affilliation | Pontifıcia Universidade Catolica de Rio Grande do Sul. Grupo de Parasitologia Medica. Porto Alegre, RS, Brasil | pt_BR |
Affilliation | Pontifıcia Universidade Catolica de Rio Grande do Sul. Grupo de Parasitologia Medica. Porto Alegre, RS, Brasil | pt_BR |
Affilliation | Fundação Oswaldo Cruz. Instituto Rene Rachou. Laboratorio de Esquistossomose. Belo Horizonte, MG, Brasil | pt_BR |
Affilliation | Universidade Federal de Minas Gerais. Instituto de Ciências Biologicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil | pt_BR |
Affilliation | Universidade Federal de Minas Gerais. Instituto de Ciências Biologicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil | pt_BR |
Affilliation | Universidade Federal de Minas Gerais. Instituto de Ciências Biologicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil | pt_BR |
Affilliation | Pontifıcia Universidade Catolica de Rio Grande do Sul. Grupo de Parasitologia Medica. Porto Alegre, RS, Brasil | pt_BR |
Affilliation | Ministerio da Saude. Instituto Evandro Chagas. Secretaria de Vigilancia em Saude. Belem, PA, Brasil | pt_BR |
Affilliation | Fundação Oswaldo Cruz. Instituto Rene Rachou. Laboratorio de Esquistossomose. Belo Horizonte, MG, Brasil | pt_BR |
Affilliation | Universidade Federal de Minas Gerais. Instituto de Ciências Biologicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil | pt_BR |
Affilliation | Universidade Federal de Minas Gerais. Instituto de Ciências Biologicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil | pt_BR |
Affilliation | Universidade Federal de Minas Gerais. Instituto de Ciências Biologicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil | pt_BR |
Subject | Schistosomiasis | pt_BR |