Vigilancia e busca ativa de casos suspeitos de dengue hemorragico em Ribeirao Preto, Sao Paulo

Abstract

A clinical-epidemiological case study was carried out to evaluate a surveillance and active search system for suspect cases of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) during a dengue epidemic in the Ribeirao Preto municipality, State of Sao Paulo, Brazil, between November 1990 and March 1991. This was the first dengue epidemic ever recorded in this region. Although dengue is a growing public health problem in Brazil, and DHF/DSS has been reported to be evolving in the Americas, health officials have shown a passive attitude towards the disease, partly due to lack of experience. Reporting dengue occurrences, both of isolated cases and of epidemics, is essential to reduce mortality. The data analyzed were collected through the official epidemiological surveillance system during the 1990- 1991 epidemic. Out of the 2,521 confirmed cases of dengue, 34 cases of febrile acute illness with hemorrhagic manifestations were identified as possible cases of DHF/DSS, as well as two deaths associated to dengue. From these 36 cases, 12 cases were confirmed by laboratory exams as dengue with hemorrhagic manifestations. Examination of clinical and laboratory data, and results of the autopsies suggested that the two deaths were cases of primary DHF/DSS. The difficulty of the health system in establishing the clinical suspicion of DHF/DSS was confirmed in the study. This resulted in delayed and inadequate clinical procedure. The present study also confirmed the need for a permanent active epidemiological surveillance system for the early identification of DHF/DSS suspect cases thus enabling quick and adequate control actions.