Dengue

Flavivirus infection endemic to equatorial regions, and classified into:

Epidemiology and Risk Factors

Epidemiology:

  • Endemic in south-east Asia, sub-Saharan Africa, and parts of South America
  • ~10% of cases require hospitalisation
    >90% of hospitalisations are children.

Pathophysiology

Single-stranded RNA genome with three structural proteins, divided into four serotypes. Infection leads to:

  • ~7 day viraemia
  • Immunity to that subtype, but not other serotypes
    Reinfection can occur with another serotype, and the resulting secondary infection is more severe than the primary one.

Aetiology

Transmitted by the Aedes mosquito, with two different patterns of outbreak:

  • Epidemic due to spread of dengue to a naïve region
  • Endemic circulation of a variety of different dengue subtypes

Clinical Manifestations

Diagnostic Approach and DDx

Investigations

Bedside:

  • Tourniquet test
    Marker of capillary fragility:
    • Inflate BP cuff to midway between systolic and diastolic pressure for 2 minutes
    • Deflate for 2 minutes
    • Count petechiae below the ACF
    • A positive test is >10 petechiae per square inch

Laboratory:

  • Blood
    • FBE
      • Haemoconcentration
      • Thrombocytopaenia
      • Leukopaenia
    • LFT
      • ↑ AST
    • IgM serology
    • Viral PCR

Imaging:

Other:

Management

Resuscitation:

Specific therapy:

  • Pharmacological
  • Procedural
  • Physical

Supportive care:

Disposition:

Preventative:

Marginal and Ineffective Therapies

Anaesthetic Considerations

Complications

Prognosis

Key Studies

References

  1. Bersten, A. D., & Handy, J. M. (2018). Oh’s Intensive Care Manual. Elsevier Gezondheidszorg.
  2. Harvey RA, Cornelissen CN, Fisher BD. Lippincott Illustrated Reviews: Microbiology (Lippincott Illustrated Reviews Series). 3rd Ed. LWW.