Zika virus: Difference between revisions

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βˆ’
== Background ==
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==Background==
   
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* Single-stranded, positive-sense RNA virus in the [[Flaviviridae]] family, genus [[Flavivirus]]
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*Single-stranded, positive-sense RNA virus in the [[Flaviviridae]] family, genus [[Flavivirus]]
βˆ’
* Discovered in 1947 in Zika Forest, Uganda
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*Discovered in 1947 in Zika Forest, Uganda
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* Vector-borne infection carried primarily by [[Vector::Aedes aegypti]] mosquitoes, but possibly also [[Vector::Aedes albopictus]] mosquitoes
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*Vector-borne infection carried primarily by [[Vector::Aedes aegypti]] mosquitoes, but possibly also [[Vector::Aedes albopictus]] mosquitoes
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* Sexual transmission appears to be possible
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*Sexual transmission appears to be possible
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* Now essentially endemic in tropics worldwide
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*Now essentially endemic in tropics worldwide
   
 
==Clinical Manifestations==
 
==Clinical Manifestations==
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*Incubation period of [[Usual incubation period::3 to 14 days]]
 
*Incubation period of [[Usual incubation period::3 to 14 days]]
 
*[[Causes::Fever]], [[Causes::rash]], [[Causes::arthralgias]], [[Causes::conjunctivitis]], and [[Causes::headache]]
 
*[[Causes::Fever]], [[Causes::rash]], [[Causes::arthralgias]], [[Causes::conjunctivitis]], and [[Causes::headache]]
  +
*May also see [[Causes::thrombocytopenia]], and can be severe enough to cause abnormal bleeding or hematomas
 
*Usually self-limited, lasting around 5 days
 
*Usually self-limited, lasting around 5 days
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  +
=== Postinfectious Complications ===
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*Can have neurological disease in some cases, primarily presenting as [[Causes::Guillain-BarrΓ© syndrome]]
 
*Can have neurological disease in some cases, primarily presenting as [[Causes::Guillain-BarrΓ© syndrome]]
  +
*Rarely, [[acute myelitis]], [[meningoencephalitis]], [[acute disseminated encephalomyelitis]], [[reverse sensory polyneuropathy]]
*With maternal infection, causes a congenital syndrome of CNS abnormalities including [[Causes::microcephaly]], intracranial calcifications, lissencephaly, pachygyria, and vision and hearing loss
 
  +
  +
=== Congenital Infection ===
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*With maternal infection, causes a [[Congenital Zika|congenital syndrome]] of CNS abnormalities including [[microcephaly]], [[CNS calcifications in neonates|intracranial calcifications]], [[lissencephaly]], [[pachygyria]], and vision and hearing loss
   
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== Differential Diagnosis ==
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==Differential Diagnosis==
   
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* [[Dengue]]
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*[[Dengue|Dengue virus]]
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*[[Chikungunya virus]]
   
  +
{| class="wikitable"
  +
!Feature
  +
![[Dengue]]
  +
!Zika
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![[Chikungunya]]
  +
|-
  +
|Asymptomatic
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|40-80%
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|35-85%
  +
|3-28%
  +
|-
  +
|Fever
  +
| +++
  +
| ++
  +
| +++
  +
|-
  +
|Rash
  +
| +
  +
| +++
  +
| ++
  +
|-
  +
|Conjunctivitis
  +
|–
  +
| ++
  +
| +
  +
|-
  +
|Arthralgia
  +
| +
  +
| ++
  +
| +++
  +
|-
  +
|Myalgia
  +
| ++
  +
| +
  +
| +
  +
|-
  +
|Headache
  +
| ++
  +
| +
  +
| ++
  +
|-
  +
|Hemorrhage
  +
| ++
  +
|–
  +
|–
  +
|-
  +
|Shock
  +
| +
  +
|–
  +
|–
  +
|-
  +
|Thrombocytopenia
  +
| +++
  +
| +
  +
|–
  +
|-
  +
|Leukopenia
  +
| ++
  +
|–
  +
| ++
  +
|}
 
==Investigations==
 
==Investigations==
   
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*Serology can be tested after 10 days of symptoms, but is non-specific
 
*Serology can be tested after 10 days of symptoms, but is non-specific
   
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== Management ==
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==Management==
   
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* Supportive
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*Supportive
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* For risk of congenital disease
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*For risk of congenital disease
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** If asymptomatic, no need to delay attempts at conception
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**If asymptomatic, no need to delay attempts at conception
βˆ’
** If symptomatic and diagnosis is confirmed, counsel to delay attempts at conception for 2 months (women) or 3 months (men) after return from the endemic area
+
**If symptomatic and diagnosis is confirmed, counsel to delay attempts at conception for 2 months (women) or 3 months (men) after return from the endemic area
βˆ’
** If symptomatic and diagnosis is not confirmed, then discuss with the patient
+
**If symptomatic and diagnosis is not confirmed, then discuss with the patient
βˆ’
** If the woman is pregnant and man has compatible symptoms, should abstain from unprotected sex for the duration of pregnancy
+
**If the woman is pregnant and man has compatible symptoms, should abstain from unprotected sex for the duration of pregnancy
   
 
[[Category:Flaviviridae]]
 
[[Category:Flaviviridae]]

Latest revision as of 09:50, 20 September 2020

Background

  • Single-stranded, positive-sense RNA virus in the Flaviviridae family, genus Flavivirus
  • Discovered in 1947 in Zika Forest, Uganda
  • Vector-borne infection carried primarily by Aedes aegypti mosquitoes, but possibly also Aedes albopictus mosquitoes
  • Sexual transmission appears to be possible
  • Now essentially endemic in tropics worldwide

Clinical Manifestations

Postinfectious Complications

Congenital Infection

Differential Diagnosis

Feature Dengue Zika Chikungunya
Asymptomatic 40-80% 35-85% 3-28%
Fever +++ ++ +++
Rash + +++ ++
Conjunctivitis – ++ +
Arthralgia + ++ +++
Myalgia ++ + +
Headache ++ + ++
Hemorrhage ++ – –
Shock + – –
Thrombocytopenia +++ + –
Leukopenia ++ – ++

Investigations

  • Serum rRT-PCR, ideally done within 10 days of symptoms onset
  • Serology can be tested after 10 days of symptoms, but is non-specific

Management

  • Supportive
  • For risk of congenital disease
    • If asymptomatic, no need to delay attempts at conception
    • If symptomatic and diagnosis is confirmed, counsel to delay attempts at conception for 2 months (women) or 3 months (men) after return from the endemic area
    • If symptomatic and diagnosis is not confirmed, then discuss with the patient
    • If the woman is pregnant and man has compatible symptoms, should abstain from unprotected sex for the duration of pregnancy