Dengue Fever Symptoms, Diagnosis and Treatments

Introduction

Dengue fever is an illness caused by a virus of the family Flaviviridae, specifically the Dengue viruses (ENV1 to ENV4).

Transmission

Dengue fever is transmitted by mosquitoes, particularly the Aedes aegypti and Aedes albopictus species.

Pathogenesis

The virus fuses with a host cell, possibly Langerhans cells in the skin, mediated by a viral envelope glycoprotein.

Once inside the cell, the viral RNA replicates, assembles in the endoplasmic reticulum (ER), and is released to infect other cells.

Signs and Symptoms

Variable presentation, from asymptomatic to life-threatening.

More common in children.

Symptoms include sudden onset fever (>38.5°C), headache, retro-orbital eye pain, muscle and joint pain, nausea, vomiting, diarrhea, and abdominal pain.

Other symptoms: lymphadenopathy, hepatomegaly, maculopapular rash, respiratory symptoms (less common).

Warning signs of severe disease: persistent vomiting, abdominal pain, leukopenia, thrombocytopenia, elevated liver enzymes.

Clinical Phases

Febrile Phase: Symptoms begin, lasts 3-7 days.

Critical Phase: Thrombocytopenia and increased risk of bleeding, occurs 3-7 days after fever onset, more likely in secondary infections and patients with comorbidities.

Recovery Phase: Resolution of symptoms, may have a new maculopapular rash, and chronic fatigue lasting weeks to months.

Diagnosis and Treatment

Diagnosis: Serology (anti-dengue IgM antibodies) or PCR to detect viral genomes.

Treatment: Supportive care, acetaminophen for symptom relief (avoid ibuprofen due to bleeding risk).

Prevention: Dengue vaccination, though it may not fully protect against infections, reduces symptoms and length of infection.

Conclusion

Dengue fever is a significant cause of fever in returned travelers, especially in tropical and subtropical climates.

Understanding its pathogenesis, clinical phases, and management is crucial for healthcare professionals.