Difference between revisions of "Dengue Virus"

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|Category=Uveitis
 
|Category=Uveitis
 
|Assigned editor=Jessica.Shantha
 
|Assigned editor=Jessica.Shantha
|Date reviewed=February 11, 2019
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|Reviewer=Jessica.Shantha
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|Date reviewed=May 27, 2019
 
|Article status=Update Pending
 
|Article status=Update Pending
 
|Meta description=Dengue virus is a systemic infection common in tropical areas that often has ocular manifestations.
 
|Meta description=Dengue virus is a systemic infection common in tropical areas that often has ocular manifestations.

Revision as of 23:50, May 27, 2019

Assigned editor:
Review:
Assigned status Update Pending
 by Jessica Shantha, MD on May 27, 2019.


Dengue virus is an RNA virus of the flavivirus family with at least four distinct serotypes. It is the cause of dengue fever which is associated with headache, retro-orbital pain, joint and bone pain (hence "breakbone fever"), fever and rash. The most serious form of dengue infection is known as dengue hemorrhagic fever which is characterized by thrombocytopenia and potentially multi-system organ failure.

Disease Entity

Disease

  • Dengue is a mosquito-borne viral illness that is spreading rapidly to become endemic in tropical and subtropical regions of the world.
  • Dengue viruses are part of the Flaviviridae family; there are at least four dengue virus serotypes (DENV-1 to DENV-4), which result in a range of clinical manifestations, from asymptomatic, to mild febrile illness, to fatal plasma leakage and hemorrhagic shock.
  • Infection with one serotype results in long-term immunity only to that specific serotype, and not to the others.
  • Dengue often is difficult to diagnose, and a presumptive diagnosis often is established initially based on clinical signs and symptoms, while waiting for laboratory confirmation.
  • For many patients, the disease is self-limited, ending with full recovery after fever resolves on about day 4 or 5.
  • Other potentially life-threatening diagnoses, such as malaria and typhoid fever, should be included on the differential diagnosis.
  • Prompt initiation of rehydration therapy with intravenous crystalloid and colloid infusions is the mainstay of treatment in patients with more severe dengue.
  • Current vector control efforts have not been sufficient to control dengue.
  • No specific antiviral therapy exists at this time.
  • A tetravalent dengue vaccine is in clinical trials.

Etiology

Aedes aegypti.jpg

Risk Factors

Travel to endemic areas and exposure to infected female Aedes aegypti mosquitoes.

Global Dengue Burden 2014
Aedes aegypti US 2017.JPG

General Pathology

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Pathophysiology

Dengue virus employs many mechanisms to utilize host cell machinery in order to facilitate viral replication. Dengue virus translation and replication occur in the endoplasmic reticulum of host cells, which experiences rearrangement and expansion during infection. Although the initial rearrangement is independent of the unfolded protein response (UPR),  dengue virus alters the UPR in order to cope with endoplasmic reticulum stress throughout infection.  Particular non-structural proteins (NS4A, NS2B/3) induce the UPR to slow host cell death during viral replication.  In addition, dengue virus leads to autophagy and regulates lipid metabolism to enhance replication,  and a functional autophagy pathway is essential to virus maturation and the production of infectious virions.

Dengue Pathophysiology.jpg

Primary prevention

Avoidance of Aedes aegypti mosquitoes.

Diagnosis

  • Serologic testing with enzyme-linked immunosorbent assay (ELISA) or hemagglutinin inhibition
  • Viral antigen (NS1) detection
  • Viral isolation and identification using cell culture
  • Detection of viral RNA by polymerase chain reaction (PCR)

History

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Physical examination

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Ocular Signs

  • Uveitis
  • Maculopathy
  • Dengue Maculopathy: OCT-A

Ocular Symptoms

  • Photophobia
  • Decreased visual acuity

Clinical diagnosis

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Diagnostic procedures

Differential diagnosis

  • Chikungunya virus
  • Zika virus infection
  • Ebola virus
  • Hemorrhagic fever viruses
  • River Virus
  • Orbivirus
  • West Nile encephalitis
  • Roseola infantum
  • Scarlet fever
  • Idiopathic thrombocytopenic purpura
  • Influenza
  • Leptospirosis
  • Malaria
  • Meningitis
  • Rickettsial Infection
  • Rocky Mountain Spotted Fever (RMSF)
  • Typhus
  • Viral Hepatitis

Management

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General treatment

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Medical therapy

The US Food and Drug Administration (FDA) has not approved any drugs against dengue, but substantial efforts are underway to develop antiviral compounds that target viral or host factors. Advances in acute-phase diagnostic assays make early diagnosis and treatment a more realistic scenario.

Complications

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Prognosis

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Additional Resources

https://www.cdc.gov/dengue/

References

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