Serological evidence of leptospirosis in patients with a clinical suspicion of dengue in the State of Ceará, Brazil.

Introduction: Dengue and leptospirosis are two febrile illnesses of great clinical and epidemiological importance in Brazil. Their significant degree of symptomatic similarity makes clinical diagnosis difficult.Objective: To diagnose leptospirosis differentially in patients with clinically suspected dengue.Materials and methods: In this study, 86 patients with clinically suspected dengue underwent virological and serological diagnostic evaluations for dengue (reverse transcriptase polymerase chain reaction, NS1 immunochromatographic test, and NS1 enzyme-linked immunosorbent assay, ELISA), as well as tests to detect immunoglobulin M (IgM; IgM/IgG Rapid Test and IgM ELISA). The same patients were subsequently evaluated for leptospirosis using Rapid Test IgG/IgM (Bioeasy®) and Leptospira IgM ELISA (PanBio®).Results: Of the 86 patients, 48 (55.8%) had positive results for dengue in at least one of the tests and five (7.35%) showed positive reactions for leptospirosis.Conclusion: During dengue epidemics, this disease may be misdiagnosed as other infections, including leptospirosis, when diagnosis is based on nonspecific clinical and laboratory criteria alone.Introducción. El dengue y la leptospirosis son dos enfermedades febriles de gran importancia clínica y epidemiológica en Brasil, y presentan una similitud sintomatológica significativa, lo cual dificulta el diagnóstico clínico.Objetivos. Hacer el diagnóstico diferencial para leptospirosis en pacientes con sospecha clínica de dengue.Materiales y métodos. En este estudio, 86 pacientes con sospecha clínica de dengue fueron sometidos a examen para el diagnóstico de dengue mediante pruebas de virología y serología (RT-PCR, prueba de inmunocromatografía NS1 y ELISA-NS1) y pruebas para la detección de IgM (prueba rápida IgM/IgG y ELISA-IgM). En los mismos pacientes también se evaluó la presencia de leptospirosis mediante la prueba rápida IgG/IgM (Bioeasy®) y ELISA IgM-Leptospira (PanBio®).Resultados. De los 86 pacientes, 48 (55,8 %) fueron positivos para dengue en, por lo menos, una de las pruebas y 5 (7,35 %) presentaron reacciones positivas para leptospirosis.Conclusión. Durante las epidemias de dengue, otras infecciones y entre ellas la leptospirosis, pueden dar lugar a confusiones cuando se el diagnóstico se hace únicamente con base en criterios inespecíficos clínicos y de laboratorio.Introduction: Dengue and leptospirosis are two febrile illnesses of great clinical and epidemiological importance in Brazil, demonstrating significant symptomatic similarity that makes clinical diagnosis difficult.Objectives: To differentially diagnose leptospirosis in patients with clinically suspected dengue.Materials and methods: In this study, 86 patients with clinically suspected dengue underwent virological and serological diagnostic evaluations for dengue (reverse transcriptase polymerase chain reaction, NS1 immunochromatographic test, and NS1 enzyme-linked immunosorbent assay [ELISA]), and tests to detect immunoglobulin M (IgM; IgM/IgG Rapid Test and IgM ELISA). Then, the same patients were also evaluated for leptospirosis using Rapid Test IgG/IgM (Bioeasy®) and Leptospira IgM ELISA (PanBio®).Results: Of the 86 patients, 48 (55.8%) had positive results for dengue in at least one of the tests and 5 (7.35%) showed positive reactions for leptospirosis.Conclusion: During dengue epidemics, diagnosis of dengue may be confused with other infections, among which is leptospirosis, when diagnosed only by using nonspecific clinical and laboratory criteria