Evaluación de la definición de caso probable de dengue clásico durante el brote de dengue en Lima, 2005.
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 ≥5 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 ≤4 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.