Virus

Chikungunya

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Chikungunya

  • See Also
  1. Alphavirus
  2. Arbovirus
  • Definitions
  1. Chikungunya
    1. Mosquito-borne Alphavirus named for "To walk bent over" in Tanzanian
  • Pathophysiology
  1. Mosquito borne (Arbovirus) Alphavirus in the family Togaviridae (Togavirus)
    1. Most other Alphaviridae cause Encephalitis
    2. Togaviridae are enveloped, Icosahedral, single stranded RNA Viruses
    3. Togaviridae are Message Sense RNA Viruses (Positive Stranded, +ssRNA)
      1. Message sense RNA (+ssRNA) are identical to Messenger RNA (mRNA)
      2. Like mRNA, +ssRNA may be immediately translated by host ribosomes into Protein
  2. Mosquito vectors
    1. Aedes aegypti
    2. Asian tiger Mosquito
  3. Regions
    1. Originally described in East Africa in 1950s
    2. Kenya
    3. Somalia
    4. Bangladesh
    5. Madagascar
    6. Sri Lanka
    7. Caribbean
    8. Mexico
    9. Brazil
    10. Columbia
    11. Nigeria
    12. Pakistan
    13. Philippines
    14. Thailand
  • Symptoms
  1. Symptoms follow 2-4 days (up to 12 days) of asymptomatic Incubation Period
  2. Fever with abrupt onset
    1. Fever may be absent
    2. Undulating fever may occur (similar to Dengue Fever)
  3. Pharyngitis
  4. Back pain
  5. Headache
  6. Polyarthralgias, especially small joints (e.g. ankles, wrists, toes, fingers)
    1. May be severe, similar to Dengue Fever
  • Signs
  1. Rash (present in 50% of patients)
    1. Pruritic rash
    2. Starts with Flushing and then maculopapular rash involving trunk and extremities
    3. Desquamation of palms and soles
    4. Bullous Facial Edema
  2. Other uncommon presentations
    1. Meningoencephalitis (children)
    2. Ocular changes
  • Labs
  1. Complete Blood Count
    1. Lymphocytosis (or often normal WBC Count)
    2. Thrombocytopenia
  2. Chikungunya IgM
    1. May be falsely negative in first 2 weeks
  • Differential Diagnosis
  1. Dengue Fever
  • Management
  1. Supportive care
  2. Avoid Aspirin and NSAIDs (until Dengue is excluded)
  • Prevention
  1. See Prevention of Vector-borne Infection
  2. Chikungunya Vaccine
    1. Indicated to regions with current outbreak or prolonged travel (>6 months) to more endemic regions
    2. Age 12 to 18 years old: Virus-like particle Chikungunya Vaccine
    3. Age >18 years: Live-Attenuated Chikungunya Vaccine
  • Complications
  1. Chronic Arthritis
    1. NSAIDs
    2. Corticosteroids
    3. Chloroquine or Hydroxychloroquine
  • Resources
  1. CDC
    1. https://www.cdc.gov/chikungunya/
  • References
  1. Martin (2010) Park Nicollet Primary Care Update CME, Minneapolis, MN
  2. Huntington (2016) Am Fam Physician 94(7): 551-7 [PubMed]