Clinical characteristics of dengue and dengue hemorrhagic fever in a medical center of southern Taiwan during the 2002 epidemic

Background and Purpose: This study investigated the clinical manifestations and risk factors for dengue fever (DF) and dengue hemorrhagic fever (DHF) and disease severity during the 2002 outbreak in the Kaohsiung area. Methods: We analyzed the clinical characteristics of 644 patients with virologically or serologically positive results for dengue virus at Kaohsiung Medical University Hospital from January 1 to December 31, 2002. Results: The case rate peaked in November. The male-to-female ratio was 1:1.2 and the mean age was 47.5 ± 17.9 years (range, 7 months to 88 years). The criteria for DHF were fulfilled in 232 cases, including 12 cases of dengue shock syndrome (DSS). The most common symptoms were fever (96.1%), myalgia (68.5%), headache (55.4%), and skin rash (53.7%). Hemorrhagic manifestations were noted in 73.0% of patients. The mean age of patients with DHF/DSS was 53.6 ± 16.3 years, and the highest incidence occurred in those aged 60-69 years (27.2%). Significant risk factors for DHF/DSS were age >65 years, diabetes mellitus, hypertension, and uremia. Gallbladder wall thickening was found in 64.7% of DHF cases who underwent abdominal ultrasound examination. 164 of the 232 DHF cases (71%) were discharged without a diagnosis of DHF. The number of DHF cases identified by our study was nearly equal to that reported through the established passive surveillance system (232 cases vs 242). Conclusions: DHF was under-reported in hospital, suggesting that continuous surveillance and education for clinicians in the recognition of DHF, especially in elderly patients and those with chronic pre-existing comorbidities, is needed.