Increased detection of schistosomiasis with Kato-Katz and SWAPIgG- ELISA in a Northeastern Brazil low-intensity transmission area

• Autor(a) principal: Pinheiro, Marta Cristhiany Cunha
• Data de Publicação: 2012
• Outros Autores: Oliveira, Sara Menezes de, Hanemann, Ana Lúcia de Paula, Queiroz, José Ajax Nogueira, Bezerra, Fernando Schemelzer Moraes, Carneiro, Teiliane Rodrigues
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/6893
• topic: Esquistossomose; Schistosoma mansoni; Ensaio de Imunoadsorção Enzimática

Introduction: The laboratory diagnosis of schistosomiasis is based mainly on the detection of parasite eggs in stool samples through the Kato-Katz (KK) technique, reading one slide by test. However, a widely known limitation of parasitological methods is reduced sensitivity, particularly in low endemic areas. Methods: To increase sensitivity, we conducted further slide readings from the same stool sample using the parasitological method associated with a serological test. We used the KK method (three slides) and the IgG anti-Schistosoma mansoni– enzyme-linked immunosorbent assay (ELISA) technique to diagnose schistosomiasis in low endemic areas in the Brazilian State of Ceará. Fecal samples and sera from 250 individuals were analyzed. Results: Sixteen percent and 47.2% of samples were positive in parasitological tests and serological tests, respectively. Parasitological methods showed that 32 (80%) individuals tested positive on the first slide, 6 (15%) on the second slide, and 2 (5%) on the third. The performance of the ELISA test in the diagnosis, using the KK method as diagnostic reference, showed a negative predictive value of 100%, with specificity and positive predictive values of 62.8% and 33.9%, respectively. Conclusions: In this study, the increase from one to three slides analyzed per sample using the KK technique was shown to be a useful procedure for increasing the diagnostic sensitivity of this technique.