What are the recommended public health measures and treatment protocols for a large outbreak of dengue fever?

Managing a Large Dengue Outbreak: Public Health and Clinical Response

For a dengue outbreak of 62,313 cases, implement aggressive vector control through daily mosquito fogging with non-residual insecticides, establish symptomatic outpatient management with daily complete blood count monitoring for patients at risk of shock, and prioritize vaccination of children aged 9-16 years with laboratory-confirmed previous dengue infection in endemic areas.

Vector Control Measures

Immediate mosquito control is the cornerstone of outbreak response. 1

• Daily fogging with non-residual insecticides should be implemented throughout affected areas to rapidly reduce adult mosquito populations 1
• Deploy Wolbachia-infected mosquitoes, indoor residual spraying, sterile insect techniques, and mosquito-disseminated insecticides as integrated control technologies 2
• Mobilize community activities for elimination of potential breeding sites through home cleaning campaigns, facilitated by social media and health education initiatives 2

Clinical Case Management and Risk Stratification

Diagnosis

Dengue PCR should be performed within 1-8 days post-symptom onset for definitive diagnosis. 1

• Use reverse transcriptase PCR (RT-PCR) up to day 5 of illness for direct pathogen demonstration 3
• After day 5, use IgM serology for diagnosis 1
• Establish laboratory capacity for serotyping to identify circulating DENV serotypes, as this guides control measures 4

Risk Stratification and Triage

Classify patients into three risk groups based on clinical findings and comorbidities to determine outpatient versus hospital management. 3

High-risk patients requiring hospitalization include those with: 1, 3

• Rising hematocrit with falling platelet counts (indicating plasma leakage)
• Signs of shock (hypotension, tachycardia, poor perfusion)
• Mucosal hemorrhages or severe bleeding
• Severe organ involvement (hepatitis, encephalopathy)

Low-risk patients can be managed as outpatients with: 1

• Daily complete blood count monitoring to detect early warning signs
• Clear instructions to return immediately if warning signs develop
• Adequate oral hydration

Treatment Protocol

Treatment is entirely supportive, as no specific antiviral therapy exists. 3, 5

For outpatient management: 1, 5

• Symptomatic treatment with adequate oral or intravenous rehydration for mild-to-moderate disease
• Avoid aspirin and NSAIDs due to bleeding risk; use acetaminophen/paracetamol for fever control 1
• Daily follow-up with complete blood count monitoring during the critical phase (typically days 3-7 of illness)

For hospitalized patients with severe dengue: 3, 5

• Aggressive intravenous fluid replacement to maintain adequate perfusion
• Blood product transfusion for patients with significant hemorrhage
• Close monitoring for fluid overload and shock
• Intensive care support for dengue shock syndrome

Vaccination Strategy

Dengvaxia vaccination should be prioritized for children aged 9-16 years with laboratory-confirmed previous dengue infection living in endemic areas. 4, 6

• This is the first dengue vaccine recommended by ACIP for use in the United States and territories 4, 6
• Laboratory confirmation of previous dengue infection is mandatory before vaccination to avoid increased risk of severe disease in dengue-naive individuals 4, 6
• Vaccination reduces risk for symptomatic disease, hospitalization, and severe dengue in this high-risk age group 4
• The Takeda vaccine has been incorporated into Brazil's public health system, with the Butantan vaccine in Phase 3 trials 2

Surveillance and Reporting

Establish robust case surveillance through ArboNET or equivalent national arboviral surveillance systems. 4

• Report all dengue cases using standardized case definitions 4
• Perform DENV serotyping on a subset of specimens to identify circulating serotypes 4
• Monitor hospitalization rates and deaths to assess outbreak severity 4

Key Clinical Pitfalls

Children and adolescents aged <20 years are disproportionately affected, accounting for approximately 50% of cases. 4

• Tailor interventions specifically for this population 4
• Hospitalization rates are high (32-45% in U.S. territories), emphasizing the need for provider education on dengue clinical management 4
• Severe dengue occurs in approximately 2% of cases with mortality of 1-5% when it develops 1, 3
• The disease follows a characteristic triphasic course: febrile phase, critical phase (days 3-7 when plasma leakage occurs), and recovery phase 3

Multisectoral Approach

A comprehensive strategy encompassing sanitary improvements, mosquito control, vaccination, and community mobilization is essential. 2

• Integrate vector control technologies into routine health services 2
• Expand vaccination coverage in eligible populations 2
• Maintain ongoing health education and community engagement 2
• Address climate change impacts, as global warming is a key driver of dengue expansion 2