Uma nova possibilidade de vigilância: identificamos todos os casos de leptospirose?

Leptospirosis is a febrile disease with a typically underestimated global incidence, especially in regions where dengue is endemic. Therefore, it is difficult to accurately determine the number of leptospirosis cases in these areas, which contributes to significant under-reporting this disease. In this study, we estimated the number of possible leptospirosis cases among dengue-like cases that were reported during 2008, 2010, and 2012 in the city of Fortaleza, northeast Brazil. Patients were evaluated for dengue and leptospirosis using immunoenzymatic tests for IgM antibodies that were specific to each pathogen. Among the suspected cases of dengue that resulted as negative in laboratory tests, 10.8% (2008), 19.2% (2010), and 30.8% (2012) were confirmed to be leptospirosis. Considering the cases reported by the surveillance authority as dengue that were subsequently discarded based on the laboratory test results, we estimate that the number of actual leptospirosis cases may be 26 to 49 times higher than those diagnosed and reported by the Health Services. Furthermore, we believe that approximately 20% of dengue-like cases may be leptospirosis cases in areas where the two diseases are endemic.A leptospirose é doença febril tipicamente subestimada em todo o mundo, principalmente em áreas que a dengue se apresenta de forma endêmica. Desta forma, há limitações importantes na compreensão do número de casos de leptospirose nessas áreas, o que proporciona maior subnotificação. Neste estudo, apresentamos estimativa de possíveis casos de leptospirose a partir de casos de dengue-símile na cidade de Fortaleza, nordeste do Brasil, durante os anos de 2008, 2010 e 2012. Os pacientes foram investigados para dengue e leptospirose utilizando testes imunoezimáticos para detecção do anticorpo, da classe IgM, específicos para cada patologia. Entre os casos suspeitos de dengue, mas que não apresentaram resultado laboratorial positivo, 10,8%; 19,2% e 30,8% foram confirmados como leptospirose nos anos de 2008, 2010 e 2012; respectivamente. Considerando os casos notificados pela vigilância de dengue e que foram, posteriormente, descartados, baseados nos resultados dos testes laboratoriais, estimamos que o número atual de casos de leptospirose pode ser de 26 a 49 vezes mais do que o detectado e notificado pelos serviços de saúde. Além disso, acreditamos que aproximadamente 20% dos casos de dengue-símile podem ser de leptospirose, em áreas onde as duas doenças ocorram de forma endêmica

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