Causes of death among hospitalized adults with dengue fever in Tainan, 2015: emphasis on cardiac events and bacterial infections

Abstract

IntroductionThe 2015 dengue outbreak in southern Taiwan caused substantial mortality rates in the elderly. We analyzed here the causes of death among adults with dengue.\n\nMethodsThe retrospective study was conducted at a medical center in Tainan from the 1st of August to 31th of December in the year 2015. The detection of the dengue NS1 antigen IgM or viral RNA in patients blood were used to diagnose dengue. Clinical courses and causes of death were retrieved from chart reviews by two intensivists.\n\nResultsThere were 4,488 cases of dengue diagnosed in the study hospital, and these cases had an in-hospital case fatality rate of 1.34% (60 cases). Of these, the mean age was 73 years and gender did not predict outcome. Twenty-eight (46.7%) cases died of severe dengue, and 29 (48.3%) deaths were possibly caused by dengue-related complications, which were mostly secondary infections (24 cases). Most of the families of fatal case (70%) signed do-not-resuscitate (DNR) orders prior to the patients death. When the dengue epidemic peaked, 13 cardiac arrest events, including out-of-hospital (5 events) and in-hospital (8) cardiac arrests at the emergency department, occurred within four weeks of the dengue epidemic. Notably, in half (7) of these cases, the patients did not search for medical aid prior to experiencing cardiac arrest. Of the 40 cases that had early death (occurring within one week after hospitalization), 60% died of severe dengue. In contrast, 50% of the 20 deaths that occurred later than one week after hospitalization were related to hospital-acquired infections, mainly pneumonia.\n\nConclusionThe elderly that experience dengue fever may die of severe dengue early or die of secondary infections later. Cardiac arrests can also occur unpredictably at the first aids, which highlight the need of professional and patient education regarding the danger signs that are related to severe dengue in an epidemic setting.\n\nAuthor summaryThe 2015 dengue outbreak in Tainan City caused substantial deaths among the elderly. The main causes of death were severe dengue and its complications. We here highlight the deaths caused by heart complications of dengue that the elderly has underlying cardiovascular comorbidities is more prone to be involved. The presentations of heart complications vary, ranging from arrythmia to myocarditis and to unexpected cardiac arrest. Clinicians should carefully evaluate and monitor the heart function of patients with severe dengue and provide timing intervention. Secondary infections or healthcare-associated infections may occur throughout the whole hospitalized course. They were also the leading causes of death during the late or recovery phase of dengue in the study. Judicious application of antimicrobial agents and early elimination of infection source may be beneficial. Overall, the substantial deaths during this outbreak may be related to low public awareness of dengue, emergency department overclouding, and lack of clinical experience. Professional and public education regarding the danger signs that are related to severe dengue is necessary in an epidemic setting.