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Case Definitions† for Use in the 2022 Monkeypox Response
On This PageSuspect Case
- New characteristic rash* OR
- Meets one of the epidemiologic criteria and has a high clinical suspicion† for monkeypox
- No suspicion of other recent Orthopoxvirus exposure (e.g., Vaccinia virus in ACAM2000 vaccination) AND demonstration of the presence of
- Orthopoxvirus DNA by polymerase chain reaction of a clinical specimen OR
- Orthopoxvirus using immunohistochemical or electron microscopy testing methods OR
- Demonstration of detectable levels of anti-orthopoxvirus IgM antibody during the period of 4 to 56 days after rash onset
Health Departments: If you have a patient that meets the probable or confirmed case definition, please contact the CDC Monkeypox Call Center at poxvirus@cdc.gov to report the case and obtain the case report form.
A PDF version of the case report form data dictionary is available here pdf icon[PDF - 3 MB] to preview only. Please do not attempt to fill out this PDF. Please contact the CDC Monkeypox Call Center to complete the case report form.
Confirmed Case
- Demonstration of the presence of Monkeypox virus DNA by polymerase chain reaction testing or Next-Generation sequencing of a clinical specimen OR isolation of Monkeypox virus in culture from a clinical specimen
Within 21 days of illness onset:
- Reports having contact with a person or people with a similar appearing rash or who received a diagnosis of confirmed or probable monkeypox OR
- Had close or intimate in-person contact with individuals in a social network experiencing monkeypox activity, this includes men who have sex with men (MSM) who meet partners through an online website, digital application (“app”), or social event (e.g., a bar or party) OR
- Traveled outside the US to a country with confirmed cases of monkeypox or where Monkeypox virus is endemic OR
- Had contact with a dead or live wild animal or exotic pet that is an African endemic species or used a product derived from such animals (e.g., game meat, creams, lotions, powders, etc.)
A case may be excluded as a suspect, probable, or confirmed case if:
- An alternative diagnosis* can fully explain the illness OR
- An individual with symptoms consistent with monkeypox does not develop a rash within 5 days of illness onset OR
- A case where high-quality specimens do not demonstrate the presence of Orthopoxvirus or Monkeypox virus or antibodies to orthopoxvirus
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†Clinical suspicion may exist if presentation is consistent with illnesses confused with monkeypox (e.g., secondary syphilis, herpes, and varicella zoster).
*The characteristic rash associated with monkeypox lesions involve the following: deep-seated and well-circumscribed lesions, often with central umbilication; and lesion progression through specific sequential stages—macules, papules, vesicles, pustules, and scabs.; this can sometimes be confused with other diseases that are more commonly encountered in clinical practice (e.g., secondary syphilis, herpes, and varicella zoster). Historically, sporadic accounts of patients co-infected with Monkeypox virus and other infectious agents (e.g., varicella zoster, syphilis) have been reported, so patients with a characteristic rash should be considered for testing, even if other tests are positive.
Categorization may change as the investigation continues (e.g., a patient may go from suspect to probable).
Page last reviewed: June 2, 2022
