ACEP Monkeypox Field Guide

Suspect Case

• New characteristic rash OR
  • deep-seated and well-circumscribed lesions, often with central umbilication; and lesion progression through specific sequential stages—macules, papules, vesicles, pustules, and scabs.
• Meets one of the epidemiologic criteria and has a high clinical suspicion for monkeypox
  • Clinical suspicion may exist if presentation is consistent with illnesses confused with monkeypox (e.g., secondary syphilis, herpes, and varicella zoster)

Probable Case

• 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

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

Epidemiologic Criteria

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, app, or social event OR
• Traveled outside the US to a country with confirmed cases of monkeypox or where monkeypox 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

Exclusion Criteria:

• An alternative diagnosis can fully explain the illness, or...
• An individual with symptoms consistent with monkeypox but who does not develop a rash within 5 days of illness onset OR
• A case where specimens do not demonstrate the presence of orthopoxvirus or monkeypox virus or antibodies to orthopoxvirus