Dengue mortality: reassessing the risks in transition countries

In Singapore in 2005 there were 14 209 documented cases of dengue fever, including 25 deaths. The epidemiology of dengue in Singapore is changing, with increasingly severe infection in adults with chronic disease being recognised. We performed a retrospective review of nine adult patients who died of dengue-related illness from 1 December 2004 to 30 November 2005 at the National University Hospital. The diagnosis was initially missed in six of the nine patients due to an atypical presentation. All the patients had significant comorbid conditions; six of the nine had diabetes mellitus. Altered mental state preceded frank shock in eight of the nine patients. Secondary bacteraemia was a contributor to death in four. Derangement of laboratory features such as prothrombin time, activated partial thromboplastin time and serum albumin level was common on presentation. Transition countries such as Singapore have an increasingly advanced health system supporting an ageing population, yet are still at risk of community-acquired tropical infections. We have found that atypical presentations, comorbidities, secondary bacterial infection and abnormal serum markers at presentation may be predictors of death from dengue.