- Viral zoonotic infection
- Incubation period 6-13 days
- Causes rash similar to smallpox
- Person-to-person transmission and mortality is significantly lower than smallpox
- Bodily fluids
- Cutaneous lesions
- Respiratory droplets — requires prolonged face-to-face contact
- Animal-to-human (zoonotic)
- Bodily fluids
- Cutaneous lesions
The majority of infections are asymptomatic.
Symptomatic infection can be divided into two phases:
1. Invasion period
- Lymphadenopathy (distinguishing feature from smallpox) — submandibular, cervical, inguinal
2. Skin eruption period (1-3 days after fever) causes a characteristic rash
- Initially maculopapular
- Transiently starts on trunk and spreads peripherally to face, palms, and soles of feet
- Progresses over 2-4 weeks to vesicles, pustules, followed by scabbing and desquamation
- Localised rash on hand(s) can occur following direct contact with infected animal or human
- Viral PCR
- Varicella (chickenpox)
- Vesicular lesions in varicella are often in different stages of development and healing
- This differs from monkeypox, where lesions are generally all at the same stage
- Lymphadenopathy is a key distinguishing feature of monkeypox
- Eczema herpeticum
- Drug rash
Management is generally supportive. Most symptomatic patients have mild self-limiting disease.
More severe cases or immunocompromised patients may require specific antiviral treatment:
- Cidofovir — no clinical data for efficacy in humans, can cause nephrotoxicity
- Brincidofovir (analogue of cidofovir)
- Secondary skin infection
- Corneal infection with ensuing visual loss
Mortality has historically ranged from 0-10%. Only three previous outbreaks have occurred:
- Central Africa 1996-1998, mortality ~10%
- USA 2003, mortality 0%
- Nigeria 2017-present (~200 confirmed cases), mortality 3%
- BK Titanji. July 18, 2021
- Tessa Davis. May 19, 2022
- John Ross. May 19, 2022
- Angela Rasmussen. May 19, 2022
- Nickson C. Monkeypox – CCC. LITFL
- Monkeypox. Centers for Disease Control and Prevention
- Monkeypox: Guidance. UK Health Security Agency
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- Alakunle E, Moens U, Nchinda G, Okeke MI. Monkeypox Virus in Nigeria: Infection Biology, Epidemiology, and Evolution. Viruses. 2020 Nov 5;12(11):1257.
BA MA (Oxon) MBChB (Edin) FACEM FFSEM. Associate Professor Curtin Medical School, Curtin University. Emergency physician, Sir Charles Gairdner Hospital. Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |