Rationale:

• Management and outcome depend on the severity of the dengue infection.
• Clinical deterioration may occur suddenly and follow a dramatic course.
• Predicting progression to severe disease is difficult, even for experienced physicians.
• Successful treatment of patients with severe dengue requires frequent clinical monitoring and intensive nursing care.
• Concurrent bacteremia may increase the morbidity and mortality associated with dengue hemorrhagic fever. Certain factors can predict the risk of concurrent bacteremia.

Evidence:

• In a study of the clinical profiles of 560 adult patients with dengue infection admitted to a hospital in Delhi, India, hematemesis (28.3%), epistaxis (26.8%), and melena (14.3%) were some of the common presentations. Mortality rates were low in patients admitted early to the hospital before the onset of shock (94).
• Published and unpublished hospital and seroepidemiologic data from the 1981 dengue hemorrhagic fever/dengue shock syndrome outbreak in Cuba were used to calculate age-specific dengue hemorrhagic fever/dengue shock syndrome hospitalization and death rates based on secondary dengue-2 infections. Children, pregnant women, and the elderly were at increased risk of morbidity and mortality, and the threshold for hospital admission should be low (32).
• In a series from Israel, 30% of travelers who contracted dengue fever were evacuated, and 66% were hospitalized (44).
• In a retrospective study of 858 patients with dengue infections admitted to a hospital in India, 109 patients with severe forms of the disease required ICU admission. The common indications for ICU admission were persistent shock (39 patients), need for positive pressure ventilation (29 patients, 10 of whom had ARDS), and neurologic symptoms (24 patients) (95).
• In a study of 100 patients with dengue hemorrhagic fever/dengue shock syndrome, 7 had a dual infection. Patients with a dual infection were older and tended to have prolonged fever, higher frequencies of acute renal failure, gastrointestinal bleeding, altered consciousness, unusual dengue manifestations, and dengue shock syndrome. Acute renal failure (OR, 51.5), and prolonged fever (more than 5 days; OR, 26.1) were independent risk factors for dual infection (94).

Comments:

• It is essential to assess the severity of the dengue infection because it influences management and outcome (96).
• Early identification of the leakage phase, with prompt resuscitation, helps to reduce complications and improve outcome.
• High-risk patients requiring special attention include infants under age 1 and patients with obesity, massive bleeding, changes in the level of consciousness (restless, irritability), or underlying disease (heart disease, hemoglobinopathy, chronic renal insufficiency).
• Vascular permeability resulting in plasma leakage is the hallmark of severe dengue. Early signs of plasma leakage include hemoconcentration, pleural effusions, and ascites. Warning signs of severe dengue include circulatory compromise or shock (cold extremities, weak radial pulse, prolonged capillary refill), altered sensorium (unconscious, lethargic, combative), mucosal bleeding (hematemesis, melena, or bleeding from the nose or gums), and unusual manifestations (hepatic damage, cardiomyopathy, encephalopathy, and encephalitis).
• The condition of patients who present without adverse signs may deteriorate over the next 24 hours despite prompt hospitalization and apparently adequate treatment.
• The short interval between the onset of hemorrhage and death makes rapid medical intervention for dengue hemorrhagic fever/dengue shock syndrome a critical factor for survival.
• There is potential for concurrent bacteremia in patients with dengue hemorrhagic fever/dengue shock syndrome and prolonged fever (more than 5 days) and/or acute renal failure.
• Concurrent bacteremia may be overlooked because of the overlapping clinical manifestations. Dual infections must be actively sought and, if present, treated early with antibiotics.