The purpose of this study is determine the ability of bedside ultrasound performed in the Emergency Department and Outpatient Department can predict the severity of disease during a Dengue Fever outbreak in children, in Siem Reap, Cambodia. Our hypothesis is that the presence of gallbladder wall thickening, pulmonary edema/effusions, ascites, pericardial effusion in children correlates with progression to more severe disease.

Dengue fever has various levels of severity, from mild disease to severe hemorrhagic complications and shock. Dengue is endemic world-wide and has been found in the United States. The mortality from dengue fever can be as high as 15-20%, with nearly 22,000 deaths annually, most of them children (Reddy, 2013). There is no reliable way to immediately predict which children presenting with a fever during a Dengue fever outbreak will progress to more severe disease. Some children with dengue fever will improve with limited clinical interventions, but others require intensive therapy. Limited healthcare resources in developing countries make decisions on treatment or disposition difficult as many children and poor clinical decision increase morbidity and mortality. In more developed countries such as the United States, early identification of patients with dengue fever has the potential to identify children who may benefit from early interventions. Identifying those patients is the first step in exploring early therapies to effect mortality. Previous research has demonstrated that intrathoracic/ peritoneal fluid and gallbladder wall thickening is associated with more severe disease for hospitalized patients with dengue (Michels, 2013). The investigators will explore earlier presentations to the emergency department and outpatient department.

The study hypothesis is that the presence of early sonographic findings in children correlates with progression to more severe disease. The study specific aim is to determine the association between sonographic features of dengue and disease progression and clinical outcome in children with dengue fever.

This study is a prospective observational clinical study in the emergency department of the Angkor Hospital for Children in Siem Reap, Cambodia. Study subjects will include children 16 years or less, who present during a dengue outbreak with suspected dengue. Subjects include children with an acute febrile illness and criteria for dengue based on 2010 WHO guidelines (fever and two of the following criteria: anorexia and nausea, rash, aches and pains, warning signs, leukopenia, positive tourniquet test). Clinicians will determine their clinical suspicion of dengue, intended therapeutic interventions and disposition following a history and physical exam. Study personnel will perform diagnostic bedside ultrasound imaging of the gallbladder, peritoneal, cardiac, and pleural spaces. Patients will be followed to determine clinical outcome, therapeutic interventions and disposition. The primary endpoint is progression of disease.

Inclusion Criteria:

1. Fever
2. Clinical suspicion of non-severe dengue (with or without warning signs). (WHO 2010 guidelines)
3. Not a prisoner or ward of the state
4. Parents able and willing to give consent.

Exclusion Criteria:

• Allergic to US gel
• Known pleural or pericardial effusion
• Unstable vital signs
• Severe dengue

Study subjects will include children 16 years or less, who present during the annual dengue outbreak with suspected dengue fever. Subjects include children with fever and two of the following criteria: anorexia and nausea, rash, aches and pains, warning signs, leukopenia, positive tourniquet test.