Mpox (formerly called monkeypox) is a disease that infects both humans and animals, namely rodents and non-human primates. It is caused by the monkeypox virus (MPXV), a DNA virus that belongs to the Orthopoxvirus genus, which also includes variola virus (the causative agent of smallpox), vaccinia virus (the virus used in the smallpox vaccine) and cowpox virus. Notably, chickenpox, another pox-like disease that displays some similarities in symptomology, is caused by varicella-zoster virus and is not related to mpox.
Mpox is spread through direct person-to-person contact, either via respiratory droplets or exposure to infectious lesions or other bodily fluids. It may also be passed from mother to child and may be contracted by touching contaminated surfaces or handling infected animals, animal feces or bedding.
Mpox vs. Smallpox
Similarities
The symptoms of mpox and smallpox are very similar. Both viruses cause fever, chills, headaches, muscle aches and fatigue, as well as a characteristic rash with fluid-filled lesions that are concentrated on the face, mouth and extremities. Notably, during the 2022 mpox outbreaks, increased oral and anogenital lesions have been reported.
Differences
The biggest differences between mpox and smallpox are that mpox has a much lower fatality rate and broader known host range than smallpox. Depending on the clade, mpox has a case fatality rate of 1-10%. While smallpox is fatal in 30-50% of cases, the fact that humans are the only known reservoir was instrumental in smallpox eradication in 1980.
Mpox vs. COVID-19
Will outbreaks of mpox (formerly called monkeypox) reach the scale of the COVID-19 pandemic? This article highlights similarities and differences between each disease and the viruses that cause them.Mpox Resources
Hear From Experts
What Is Mpox? How Do You Catch It and Is There a Vaccine?
Mpox Clinical Insights With Dr. Daniel Griffin
Mpox answers, including their origin, clinical presentation, diagnosis, treatment, and overall risk.
Reddit: Ask Us Anything...About Mpox
In a recent Ask Me Anything, hosted on Reddit, 91麻豆天美 experts in infectious diseases answer questions and counter mis-information about mpox..Timeline of Outbreaks
- 1958: mpox virus is first discovered among laboratory monkeys who exhibited pox-like disease.
- 1970: the first human case of mpox is reported in the Democratic Republic of Congo (DRC) when a 9-month-old boy was found to be infected.
- Following the first documented human case, mpox is reported in 11 different African countries.
- The disease is considered endemic to Cameroon, the Central African Republic, DRC, Gabon, Ghana, Cote D’Ivoire, Liberia, Nigeria, the Republic of the Congo and Sierra Leone.
- 2003: mpox is first reported in the U.S. Cases in non-endemic countries have been historically rare.
- Jan 1-Sept. 13, 2020: approximately 4,594 suspected global cases of mpox and 171 deaths related to the virus are reported.
- May 2022: reports of mpox outbreaks in non-endemic countries begin to circulate.
- June 30, 2022: there are almost 400 confirmed cases of mpox in the U.S. (the largest outbreak in the country since 2003), nearly 1,200 cases reported in the U.K. and at least 29 other non-endemic countries reporting mpox cases.
- Dec. 7, 2023: CDC issues health advisory about the occurrence and geographic spread of clade I Monkeypox virus (MPXV) in the Democratic Republic of the Congo (DRC).
- Jan. 2023-Aug. 7, 2024: DRC reports the largest number of suspected cases of clade I MPXV ever annually on record.
- July 2024: Burundi, Rwanda, and Uganda report confirmed cases of mpox.
- Aug. 7, 2024: CDC issue health advisory to provide additional info about the mpox outbreak in the DRC.
- Aug. 14, 2024: WHO determines that the growing number of mpox cases constitutes a public health emergency of international concern.
Zoonoses
Zoonotic diseases, those transmitted between humans and animals, account for 75% of new or emerging infectious diseases. Mpox is a zoonotic disease, highlighting the importance of predicting and preventing spillover events. The future of public health depends on this, particularly as interactions with wildlife and domestic animals increase.