What is the recommended management for a patient suspected of having dengue fever, particularly those with recent travel history to endemic areas or exposure to infected mosquitoes?

Management of Suspected Dengue Fever

For patients with suspected dengue fever and recent travel to endemic areas, immediately perform nucleic acid amplification testing (NAAT/PCR) on serum if symptoms are ≤7 days, or IgM antibody testing if symptoms are >7 days, while initiating supportive care with aggressive oral hydration (>2500ml daily), acetaminophen for symptom relief, and daily monitoring for warning signs that indicate progression to severe disease. 1

Diagnostic Approach

Initial Testing Strategy

• For symptoms ≤7 days: NAAT/PCR on serum is the preferred initial test, as viral nucleic acid is detectable during the acute viremic phase 2, 1
• For symptoms >7 days: IgM capture ELISA (MAC-ELISA) becomes the primary diagnostic test, as antibodies develop after the first week 2, 1
• NS1 antigen detection is useful from day 1 to day 10 after symptom onset and can be performed alongside NAAT 3

Clinical Diagnostic Criteria

Suspect dengue in any patient presenting with:

• Fever plus at least one of: nausea, vomiting, rash, headache, retro-orbital pain, myalgia, arthralgia, positive tourniquet test, or leukopenia 1
• Travel to or residence in endemic areas within the past 14 days (incubation period 4-8 days) 1, 4
• Exposure to day-biting Aedes mosquitoes (particularly Aedes aegypti) 1

Special Population: Pregnant Women

• Test ALL pregnant women by NAAT for both dengue AND Zika virus, regardless of outbreak patterns, due to risk of maternal death, hemorrhage, preeclampsia/eclampsia, and vertical transmission 2, 1
• Perform testing on both serum and urine specimens collected within 12 weeks of symptom onset 2

Risk Stratification and Disposition

Warning Signs Requiring Hospitalization

Admit patients immediately if ANY of the following are present:

• Persistent vomiting (unable to tolerate oral fluids) 1, 3
• Severe abdominal pain or tenderness 3
• Clinical fluid accumulation (pleural effusion, ascites) 3
• Mucosal bleeding 3
• Lethargy or restlessness 3
• Hepatomegaly 3
• Rising hematocrit (>20% increase from baseline) with concurrent thrombocytopenia 1, 3

Additional Hospitalization Criteria

• Thrombocytopenia ≤100,000/mm³, particularly when declining rapidly 1
• Narrow pulse pressure ≤20 mmHg or hypotension 1
• Pregnant women with confirmed or suspected dengue 1
• Severe dengue: plasma leakage, severe bleeding, organ failure, or dengue shock syndrome 1

Outpatient Management Criteria

Patients can be managed as outpatients if:

• No warning signs present 1
• Platelet count >100,000/mm³ without rapid decline 1
• Stable hematocrit without evidence of hemoconcentration 1
• Able to maintain adequate oral hydration 1

Supportive Management

Fluid Management

• For patients without shock: Ensure aggressive oral hydration with oral rehydration solutions, aiming for >2500ml daily 1
• For dengue shock syndrome: Administer initial fluid bolus of 20 mL/kg isotonic crystalloid over 5-10 minutes with immediate reassessment 1, 3
• Consider colloid solutions for severe shock with pulse pressure <10 mmHg 1

Pain and Fever Management

• Use acetaminophen ONLY at standard doses for pain and fever relief 1
• NEVER use aspirin or NSAIDs due to significantly increased bleeding risk—this is a critical error that must be avoided 1
• For pregnant women, acetaminophen remains the safest analgesic option 1

Monitoring Requirements

• Daily complete blood count to track platelet counts and hematocrit levels 1
• Monitor for warning signs, which typically appear around day 3-7 of illness, coinciding with defervescence 3
• Continuous cardiac telemetry and pulse oximetry for patients with dengue shock syndrome 1

Management of Complications

Dengue Shock Syndrome Recognition

Diagnose dengue shock syndrome when:

• Systolic blood pressure <90 mmHg for >30 minutes 3
• Pulse pressure <20 mmHg persisting despite initial fluid resuscitation 3
• Signs of end-organ hypoperfusion: cold/clammy extremities, capillary refill time ≥3 seconds, elevated lactate >2 mmol/L 3

Critical pitfall: Narrow pulse pressure (<20 mmHg) is an earlier and more sensitive indicator than absolute hypotension—monitor closely 3

Bleeding Management

• Blood transfusion may be necessary for significant bleeding 1
• Platelet transfusions have limited role in routine dengue management 5

Persistent Hypoperfusion

• Consider vasopressors (dopamine or epinephrine) for persistent tissue hypoperfusion despite adequate fluid resuscitation 1

Discharge Criteria

Patients can be safely discharged when ALL of the following are met:

• Afebrile for ≥48 hours without antipyretics 1
• Resolution or significant improvement of symptoms 1
• Stable hemodynamic parameters for ≥24 hours without support (normal heart rate, blood pressure, capillary refill) 1
• Adequate oral intake and urine output (>0.5 mL/kg/hour in adults) 1
• Laboratory parameters returning to normal ranges 1

Post-Discharge Instructions

• Monitor and record temperature twice daily 1
• Return immediately if: temperature rises to ≥38°C on two consecutive readings, any warning signs develop, or persistent/recurrent vomiting occurs 1, 6
• If transaminases were elevated at discharge: repeat CBC and liver function tests at 3-5 days post-discharge; monitor transaminases weekly until normalized if 2-5× normal, or every 3 days if >5× normal 1

Common Pitfalls to Avoid

• Never delay fluid resuscitation in patients showing signs of shock 1
• Avoid over-resuscitation with excessive fluids, as this can worsen outcomes given the underlying plasma leakage pathophysiology 3
• Do not prescribe antibiotics empirically without evidence of bacterial co-infection—bacterial co-infection occurs in <10% of cases, and empiric antibiotics contribute to antimicrobial resistance without clinical benefit 1
• Do not change management based solely on persistent fever without clinical deterioration or new findings—persistent fever is common and typically resolves within 5 days 1
• Recognize that fever recurring after 4 afebrile days falls outside expected dengue patterns and mandates investigation for secondary bacterial infection or alternative causes 6

Differential Diagnosis Considerations

When evaluating suspected dengue, also consider:

• Zika virus (especially in pregnant women—test for both) 2, 1
• Chikungunya 2, 1
• Malaria 2
• Other viral infections: parvovirus, adenovirus, enterovirus 1
• Bacterial infections: leptospirosis, rickettsiosis 2