Dengue Management in Primary Care Clinic
For suspected dengue in clinic, immediately perform NS1 antigen testing or dengue PCR/NAAT on serum if the patient presents within 7 days of symptom onset, then risk-stratify using warning signs to determine whether outpatient management with aggressive oral hydration and daily monitoring is safe, or whether hospital admission is required. 1, 2
Clinical Suspicion and Initial Assessment
Suspect dengue in any febrile patient with at least one of the following: nausea, vomiting, rash, headache, retro-orbital pain, myalgia, arthralgia, positive tourniquet test, or leukopenia—particularly if they traveled to or resided in endemic areas within the past 14 days. 1, 3
The incubation period ranges from 3–14 days, with most patients developing symptoms 4–8 days after mosquito exposure. 1, 4
Document the complete vaccination history for flaviviruses (yellow fever, Japanese encephalitis, Zika) because prior vaccination causes false-positive IgM results due to cross-reactivity. 1, 3
Diagnostic Testing Algorithm
For Patients Presenting ≤7 Days After Symptom Onset
Order dengue NS1 antigen test or dengue PCR/NAAT on serum as the first-line diagnostic test, because viral RNA is detectable for 4–6 days and NS1 antigen remains positive for up to 10 days after symptom onset. 1, 2, 3
NS1 antigen detection shows peak sensitivity of 75–90% during days 1–5 and can be detected as early as 1 day after symptom onset. 1, 5
If the NS1 or NAAT result is positive, this confirms acute dengue infection and no antibody testing is needed unless the case has epidemiologic significance (e.g., first local transmission, unusual clinical syndrome). 6, 1
If the NS1 or NAAT result is negative, proceed immediately to IgM antibody testing on the same serum specimen, because a negative molecular test does not exclude dengue due to declining viremia or inaccurate symptom-onset dates. 6, 1
For Patients Presenting >7 Days After Symptom Onset
Order dengue IgM capture ELISA (MAC-ELISA) as the primary diagnostic test, because IgM antibodies appear 3–5 days after symptom onset and remain detectable for 2–3 months. 1, 2, 3
A negative IgM result obtained 7 days to 12 weeks after onset effectively rules out recent dengue infection. 1, 2
If IgM is positive but definitive diagnosis is required for clinical or epidemiologic purposes, order plaque reduction neutralization test (PRNT) to differentiate dengue from other flaviviruses (Zika, West Nile, yellow fever, Japanese encephalitis). 1, 3
Interpretation of Serologic Patterns
NS1-positive / IgM-negative / IgG-negative = acute primary dengue infection in the very early phase (days 1–5). 1, 3
NS1-negative / IgM-positive / IgG-positive = either secondary dengue infection, late primary infection (>7 days), or past infection with persistent IgM; PRNT is recommended for definitive diagnosis. 1, 3
IgG-positive / IgM-negative = past dengue infection, as IgG persists for months to years. 1, 3
Risk Stratification: Who Requires Hospital Admission?
Mandatory Admission Criteria (Warning Signs of Severe Dengue)
- Hospitalize immediately if the patient exhibits any of the following warning signs: 1, 2
- Persistent vomiting (unable to tolerate oral fluids)
- Severe abdominal pain or tenderness
- Lethargy or restlessness
- Mucosal bleeding (epistaxis, gingival bleeding, hematemesis, melena)
- Rising hematocrit (>20% increase from baseline) with falling platelet count
- Thrombocytopenia ≤100,000/mm³ with rapid decline
- Severe plasma leakage (pleural effusion, ascites)
- Severe bleeding or organ failure
- Dengue shock syndrome (hypotension, narrow pulse pressure ≤20 mmHg, or hemodynamic instability)
High-Risk Populations Requiring Lower Threshold for Admission
Age >60 years warrants hospitalization or very close outpatient monitoring due to higher complication risk. 1, 2
Diabetes and hypertension together confer a 2.16-fold higher risk of dengue hemorrhagic fever (AOR 2.16; 95% CI: 1.18–3.96). 1, 2
Heart disease, immunocompromised status (HIV, transplant, chemotherapy) require hospitalization due to increased risk of decompensation and disease progression. 1, 2
Pregnant women with confirmed or suspected dengue must be hospitalized because of increased risks of maternal death, hemorrhage, pre-eclampsia/eclampsia, and vertical transmission. 1, 2, 3
Safe Outpatient Management Criteria
- Patients may be managed as outpatients only if ALL of the following are met: 1, 2
- No warning signs of severe dengue
- No significant comorbidities (no diabetes, hypertension, heart disease, immunocompromised state)
- Platelet count >100,000/mm³ without rapid decline
- Stable hematocrit without evidence of hemoconcentration
- Reliable daily follow-up available (patient can return to clinic daily or has telehealth access)
- Adequate oral hydration can be maintained (patient tolerates >2500 mL oral fluids per day)
Outpatient Management Protocol
Fluid Management
Instruct the patient to drink oral rehydration solutions targeting >2500 mL daily intake to prevent hemoconcentration and shock. 1, 2
Emphasize that adequate hydration is the single most important intervention to prevent progression to severe dengue. 1, 7
Pain and Fever Management
Prescribe acetaminophen at standard doses (650–1000 mg every 6 hours in adults; 10–15 mg/kg every 4–6 hours in children) for analgesia and antipyresis. 1, 2
Never use aspirin or NSAIDs (ibuprofen, naproxen, diclofenac) when dengue cannot be excluded, because they increase bleeding risk. 1, 2
Daily Monitoring Requirements
Order daily complete blood count (CBC) to track platelet trends and hematocrit changes, watching for warning signs of progression. 1, 2
Instruct the patient to measure temperature twice daily and return immediately if two consecutive readings reach ≥38°C or if any warning signs develop. 1, 2
Schedule daily clinic visits or telehealth check-ins during the critical phase (days 3–7 of illness) to assess for warning signs. 1, 2
Return Precautions (Red Flags)
- Instruct the patient to return immediately for: 1, 2
- Persistent or recurrent vomiting (unable to tolerate oral fluids)
- Severe abdominal pain or tenderness
- Lethargy, restlessness, or altered mental status
- Any mucosal bleeding (nosebleeds, gum bleeding, blood in vomit or stool)
- Dizziness, lightheadedness, or fainting
- Decreased urine output (<0.5 mL/kg/hour)
Hospital Management for Severe Dengue
Fluid Resuscitation for Dengue Shock Syndrome
Administer an initial isotonic crystalloid bolus of 20 mL/kg over 5–10 minutes, then reassess immediately for hemodynamic response. 1, 2
If pulse pressure remains <10 mmHg or shock persists after the initial bolus, consider colloid solutions (albumin, dextran) for severe shock. 1, 2
Avoid overly aggressive fluid boluses in resource-limited settings without access to mechanical ventilation and inotropic support, as this may increase mortality. 2
Monitoring in Hospital
Perform continuous cardiac telemetry and pulse oximetry for patients in shock. 2
Repeat CBC daily to track platelet counts and hematocrit levels during the critical phase. 1, 2
Management of Complications
For significant bleeding, transfuse blood products (packed red blood cells, platelets, fresh frozen plasma) as clinically indicated. 1, 2, 7
For persistent tissue hypoperfusion despite adequate fluid resuscitation, initiate vasopressor therapy (dopamine or epinephrine). 1, 2
Avoid empiric antibiotics unless there is clear evidence of bacterial co-infection, which occurs in <10% of viral illness cases. 2
Discharge Criteria from Hospital
- Patients may be discharged when ALL of the following are met: 1, 2
- Afebrile for ≥48 hours without antipyretics
- Resolution or significant improvement of symptoms
- Stable hemodynamic parameters for ≥24 hours without support (normal heart rate, stable blood pressure, normal capillary refill)
- Adequate oral intake and urine output (>0.5 mL/kg/hour in adults)
- Laboratory parameters (platelets, hematocrit, transaminases) returning to normal ranges
Post-Discharge Follow-Up
Arrange repeat CBC and liver function tests 3–5 days after discharge. 2
If transaminases are 2–5× upper normal limit at discharge, monitor weekly until normalized. 2
If transaminases are >5× upper normal limit at discharge, monitor every 3 days initially. 2
Special Population: Pregnant Women
Test pregnant women by NAAT for both dengue and Zika virus regardless of current outbreak patterns, because both infections cause adverse fetal outcomes. 1, 2, 3
Dengue infection during pregnancy increases the risk of maternal death, hemorrhage, pre-eclampsia/eclampsia, and vertical transmission to the fetus. 1, 2, 3
Acetaminophen remains the safest analgesic option for pregnant women with dengue. 1, 2
Differential Diagnosis to Consider
Rule out malaria first in all febrile travelers from endemic areas, as it can rapidly progress; perform a rapid malaria test before dengue testing. 6
Consider other flaviviruses: Zika virus, West Nile virus, yellow fever virus, Japanese encephalitis virus. 6, 3
Consider parasitic infections: malaria, leptospirosis. 3
Consider viral infections: rubella, measles, hepatitis A, parvovirus, adenovirus, enterovirus. 3
Consider bacterial infections: rickettsiosis, group A streptococcal infections. 3
Common Pitfalls to Avoid
Never rule out dengue based on a negative IgM test obtained during the first few days of illness, because IgM antibodies may not yet be detectable. 1, 2
Never assume acute infection based solely on positive IgM antibodies, as IgM can persist for months after the initial infection; confirm with PRNT if definitive diagnosis is needed. 1, 2
Never delay fluid resuscitation in patients showing signs of shock, as rapid intervention is critical to prevent mortality. 1, 2
Never use aspirin or NSAIDs when dengue cannot be excluded, even if the patient has not yet been tested. 1, 2
Do not prescribe empiric antibiotics (e.g., azithromycin) for dengue fever without evidence of bacterial co-infection, as this contributes to antimicrobial resistance without clinical benefit. 2
Absence of thrombocytopenia significantly reduces the probability of dengue, making it a useful rule-out finding. 2