Interim CDC Case Definition for Animal Cases of Monkeypox

Epidemiologic Criteria

  • The animal had close contact with a probable or confirmed human or animal monkeypox case within the past 21 days
    • Close contact includes petting, cuddling, hugging, kissing, licking, sharing sleeping areas, and sharing food

Clinical Criteria

  • Rash or poxvirus-like lesions, which may be:
    • Macular, papular, vesicular, or pustular
    • Generalized or localized

Other possible clinical signs:

  • Conjunctivitis with or without ocular secretion
  • Coryza (crusty nose) and/or nasal secretions
  • Cough
  • Loss of appetite
  • Lethargy
  • Labored breathing
  • Bloating
  • Fever

Case Classification

Suspect Case

  • An animal that meets the epidemiologic criteria AND has a rash, or two or more clinical signs
  • Wild mammals that meet the clinical criteria

Probable Case

  • An animal that meets the epidemiologic criteria AND presence of anti-orthopoxvirus antibodies*, OR
  • An animal with presence of monkeypox virus DNA by polymerase chain reaction

Confirmed Case

  • An animal with isolation of monkeypox virus in culture from a clinical specimen AND presence of monkeypox virus DNA by polymerase chain reaction (PCR) testing or DNA sequencing, OR
  • An animal with presence of monkeypox virus DNA by PCR or DNA sequencing AND presence of anti-orthopoxvirus antibodies*, OR
  • An animal with evidence of orthopoxvirus in pox lesions or other tissues by immunohistochemistry OR electron microscopy testing methods, AND presence of monkeypox virus DNA by PCR or DNA sequencing

* There is a lack of data regarding the timing of anti-orthopoxvirus IgG antibody production in most animal species. However, it is generally thought to be detectable between 2-4 weeks post-exposure and remains detectable for months or years.