Objective: To assess diagnostic usefulness of the probable case of classic dengue fever for identifying definite cases during the outbreak in Comas District, April - May 2005. Materials and methods: Observational and analytical non-controlled cross-sectional study. Suspected dengue fever cases from Comas District were included. These persons also had results for viral isolation or IgM ELISA, according to their time of being ill (4 days or e5 days, respectively), laboratory studies were performed at Peruvian National Institute of Health. Sensitivity, specificity, positive predictive value, and negative predictive value for the definition of a probable case of classic dengue fever, including its symptoms, taking as a gold standard viral isolation or IgM ELISA. Results: 316 patients were included, and 137 (43,4%) of them were confirmed as dengue fever cases. Viral isolation was achieved in 60 patients. Probable dengue fever case definition for patients being ill for d4 days had a 85% sensitivity, 13,40% specificity, 13,18% positive predictive value, and 74,29% negative predictive value. 77 patients who were ill for five days or more were diagnosed using IgM ELISA, and the probable dengue fever case definition for these patients had a 68,42% sensitivity, 13,40 specificity, positive predictive value, 68,42%, and 46,67% negative predictive value. Conclusions: probable case definition used in the dengue fever outbreak in Comas District, as well as the assessment of individual symptoms, has good sensitivity, but poor specificity.
Objetivos: Evaluar la utilidad diagnóstica de la definición de caso probable de dengue clásico (DCPDC) para la identificación de casos definitivos, durante el brote en el distrito de Comas, abril - mayo 2005. Materiales y métodos: Estudio observacional, analítico, no controlado de corte transversal. Se incluyeron pacientes procedentes de Comas que en el periodo de estudio presentaron sospecha de dengue y con resultados de aislamiento viral o ELISA IgM, según el tiempo de enfermedad (4 ó e5 días respectivamente) realizados en el Instituto Nacional de Salud. Se determinó la sensibilidad (S), especificidad (E), valor predictivo positivo (VPP) y negativo (VPN) de la DCPDC y de los síntomas que la conforman, tomando como prueba de oro al aislamiento viral o ELISA IgM. Resultados:Se incluyeron 316 pacientes, de los cuales se confirmaron 137 (43,4%) casos de dengue. Se detectaron 60 pacientes mediante aislamiento viral, la DCPDC en pacientes con cuatro o menos días de enfermedad presentó una S=85%, E=13,40%, VPP=13,18%, VPN= 74,29%. Se detectaron 77 pacientes con cinco o más días de enfermedad con IgM ELISA, la DCPDC en este grupo presentó S= 68,42, E= 16,28, VPP= 68,42, VPN= 46,67. Conclusiones: La DCPDC aplicada en el brote de dengue en Comas, al igual que los síntomas individuales que la conforman es sensible, pero poco específico.