Chikungunya virus: Difference between revisions

Latest revision as of 18:13, 22 August 2020

Background

Microbiology

Member of the Alphavirus genus within the Togaviridae family
- Closely related to o’nyong-nyong virus
Four genotypes: East-Central-South African, West African, Indian Ocean, and Asian

Epidemiology

The primary vectors are Aedes aegypti and Aedes albopictus mosquitoes
Endemic in most of Africa, Southeast Asia, the Philippines, and South and Central America
- There has been autochthonous transmission in Italy and Frace

Clinical Manifestations

Incubation period of 1 to 12 days
Fever, rash, and arthralgias
- Fever may be "saddleback", with remittance at 4 to 8 days followed by recrudescence for 2 weeks
- Arthritis is typically a symmetrical polyarticular arthritis that involves small joints and knees
  - Resolves over months to a year (sometimes longer), but arthralgias (± arthritis) can persist for years
- Rash is macular or maculopapular, and more often central but can involve palms and soles
Other common symptoms include headache, fatigue, nausea, vomiting, and conjunctivitis
Bloodwork shows leukopenia, thrombocytopenia, hypocalcemia, and mild to moderate transaminase elevation
Children are more likely to develop neurological symptoms (status epilepticus, complex seizures, and encephalitis) and dermatologic symptoms (bullous rash)

Differential Diagnosis

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

Management

High-dose NSAIDs
May need aggressive rheumatologic medications for arthritis
Supportive treatment

Prognosis

12% risk of chronic arthralgias up to 3 years post-infection
Neonates and elderly at highest risk for neurological sequelae

@@ Line 1: / Line 1: @@
-== Background ==
+==Background==
-=== Microbiology ===
+===Microbiology===
-* Member of the ''Alphavirus'' genus within the ''Togaviridae'' family
-** Closely related to [[o’nyong-nyong virus]]
-* Four genotypes: East-Central-South African, West African, Indian Ocean, and Asian
+*Member of the ''Alphavirus'' genus within the ''Togaviridae'' family
-=== Epidemiology ===
+**Closely related to [[o’nyong-nyong virus]]
-* The primary vectors are ''[[Aedes aegypti]]'' and ''[[Aedes albopictus]]'' mosquitoes
+*Four genotypes: East-Central-South African, West African, Indian Ocean, and Asian
-* Endemic in most of Africa, Southeast Asia, the Philippines, and South and Central America
-** There has been autochthonous transmission in Italy and Frace
+===Epidemiology===
-== Clinical Manifestations ==
-* Incubation period of [[Usual incubation period::1 to 12 days]]
-* [[Causes::Fever]], [[Causes::rash]], and [[Causes::arthralgias]]
-* Fever may be "saddleback", with remittance at 4 to 8 days followed by recrudescence for 2 weeks
-* Arthritis is typically a symmetrical polyarticular arthritis that involves small joints and knees
-** Resolves over months to a year (sometimes longer), but arthralgias (± arthritis) can persist for years
-* Rash is macular or maculopapular, and more often central but can involve palms and soles
-* Other common symptoms include headache, fatigue, nausea, vomiting, and conjunctivitis
-* Bloodwork shows leukopenia, thrombocytopenia, hypocalcemia, and mild to moderate transaminase elevation
-* Children are more likely to develop neurological symptoms (status epilepticus, complex seizures, and encephalitis) and dermatologic symptoms (bullous rash)
+*The primary vectors are ''[[Aedes aegypti]]'' and ''[[Aedes albopictus]]'' mosquitoes
-== Management ==
+*Endemic in most of Africa, Southeast Asia, the Philippines, and South and Central America
-* High-dose NSAIDs
+**There has been autochthonous transmission in Italy and Frace
-* May need aggressive rheumatologic medications for arthritis
-* Supportive treatment
+==Clinical Manifestations==
-== Prognosis ==
-* 12% risk of chronic arthralgias up to 3 years post-infection
+*Incubation period of [[Usual incubation period::1 to 12 days]]
-* Neonates and elderly at highest risk for neurological sequelae
+*[[Causes::Fever]], [[Causes::rash]], and [[Causes::arthralgias]]
+**Fever may be "saddleback", with remittance at 4 to 8 days followed by recrudescence for 2 weeks
+**Arthritis is typically a symmetrical polyarticular arthritis that involves small joints and knees
+***Resolves over months to a year (sometimes longer), but arthralgias (± arthritis) can persist for years
+**Rash is macular or maculopapular, and more often central but can involve palms and soles
+*Other common symptoms include headache, fatigue, nausea, vomiting, and conjunctivitis
+*Bloodwork shows leukopenia, thrombocytopenia, hypocalcemia, and mild to moderate transaminase elevation
+*Children are more likely to develop neurological symptoms (status epilepticus, complex seizures, and encephalitis) and dermatologic symptoms (bullous rash)
+==Differential Diagnosis==
+{| class="wikitable"
+!Feature
+![[Dengue]]
+![[Zika]]
+!Chikungunya
+|-
+|Asymptomatic
+|40-80%
+|35-85%
+|3-28%
+|-
+|Fever
+| +++
+| ++
+| +++
+|-
+|Rash
+| +
+| +++
+| ++
+|-
+|Conjunctivitis
+|–
+| ++
+| +
+|-
+|Arthralgia
+| +
+| ++
+| +++
+|-
+|Myalgia
+| ++
+| +
+| +
+|-
+|Headache
+| ++
+| +
+| ++
+|-
+|Hemorrhage
+| ++
+|–
+|–
+|-
+|Shock
+| +
+|–
+|–
+|-
+|Thrombocytopenia
+| +++
+| +
+|–
+|-
+|Leukopenia
+| ++
+|–
+| ++
+|}
+==Management==
+*High-dose [[NSAID|NSAIDs]]
+*May need aggressive rheumatologic medications for arthritis
+*Supportive treatment
+==Prognosis==
+*12% risk of chronic arthralgias up to 3 years post-infection
+*Neonates and elderly at highest risk for neurological sequelae
 [[Category:Togaviridae]]