Welcome to the Chikungunya Outbreak toolbox

Key reference documents

Guidelines for prevention and control of chikungunya fever (World Health Organization, Regional Office for South-East Asia, 2009).
Preparedness and response for chikungunya virus introduction in the Americas (Pan American Health Organization, 2011).
Chikungunya information page (World Health Organization).
Chikungunya fact sheet (World Health Organization, 2025).

Case definition

WHO suggested case definition¹

Criteria for case definition:

Clinical criteria: Acute onset of fever >38.5°C and severe arthralgia/arthritis not explained by other medical conditions.
Epidemiological criteria: Residing or having visited epidemic areas having reported transmission within 15 days prior to the onset of symptoms.

Laboratory criteria:
- Virus isolation.
- Presence of viral RNA by RT-PCR.
- Presence of virus-specific IgM antibodies in single serum sample collected in acute or
  convalescent stage.
- Four-fold increase in IgG values in samples collected at least three weeks apart.

Suspect case:

Any person with acute onset of fever >38.5°C and severe arthralgia/arthritis not explained by other medical conditions.

Probable case:

A patient meeting both the clinical and epidemiological criteria.

Confirmed case:

A suspected case with laboratory confirmation.

WHO surveillance case definition

Pilar RP, Cibrelius L, Yactayo S. Chikungunya: case definition for acute, atypical and chronic cases.
Conclusion of an expert consultation, Managua, Nicaragua, 20-21 may 2015. WER: 90; 33 409–20.
Technical guidelines for Integrated Disease Surveillance And Response In The WHO African Region (Third Edition, Brazzaville: WHO Regional Office for Africa; 2019 (p.16)).

_{1. Derived from Pilar RP, Cibrelius L, Yactayo S. Chikungunya: case definition for acute, atypical and chronic cases. Conclusion of an expert consultation, Managua, Nicaragua, 20-21 may 2015. WER: 90; 33 409–20.}