Interim CDC Case Definition for Animal Cases of Mpox

Epidemiologic Criteria

• The animal had close contact with a probable or confirmed human or animal mpox 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 mpox virus DNA by polymerase chain reaction

Confirmed Case

• An animal with isolation of mpox in culture from a clinical specimen AND presence of mpox DNA by polymerase chain reaction (PCR) testing or DNA sequencing, OR
• An animal with presence of mpox 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 mpox 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.