Mpox: An Update

Mpox (formerly called monkeypox) is a viral, infectious disease caused by the Mpox virus (MPXV). Mpox has been an endemic in West and Central Africa, however the virus became a global topic of concern in May of 2022, where there was a rise in cases in previously non-endemic countries such as Europe and North America. Spread in non-endemic regions was found to be through sexual contact, particularly affecting (but not limited to) men having sexual relations with men. Recently, there has been an increase in cases in the Democratic Republic of Congo, associated with a new outbreak.

Why is it relevant now?

There are two categories of MPXV, grouped by genetic makeup: Clade I and Clade II. Clade I, has historically been found in the Congo Basin/Central Africa region while Clade II has been found in West Africa. Infections from both clades have typically been spread through contact with infected wildlife. However, in 2022, prolonged human-to-human spread was seen by a Clade II MPXV (designated Clade IIb).

As of November 2023, there has been an increasing number of Mpox cases rising in the Democratic Republic of Congo belonging to Clade I. This is concerning, as it may indicate a higher rate of human-to-human spread of the virus rather than the primarily zoonotic transmission previously seen. Previously, many cases were often linked to contact with infected animals and wildlife, but in this outbreak there are more secondary cases, transmitted through sexual contact. This also indicates potential for similar spread of Mpox to non-endemic regions as seen in 2022.

With a rapid increase in cases over a wider area in the Democratic Republic of Congo and in densely populated cities, experts are working to learn more about how MPXV (specifically the clade I strand) spreads and how best to control the rising number of cases. There is currently no approved treatment for Mpox, although some medications are available through expanded access protocols. There is a 2 dose vaccine approved for prevention of Mpox and diagnostic testing is available.


Mpox symptoms are similar to smallpox symptoms, but are rarely fatal. They include:

-  Rash: on hands, feet, chest, genitalia

-  Fever

-  Swollen lymph nodes

-  Chills

-  Muscle ache

-  Nasal congestion

-  Sore throat

-  Cough

Those with weakened immune systems, a history of eczema, or people who are breastfeeding or pregnant may be at risk for more serious complications or death. Outbreaks of clade I MPXV have had an average case fatality rate of 10% while outbreaks of clade II MPXV have been less than 1%. It is unclear if the current clade I outbreak will see a high mortality rate.

Disease Spread and Prevention

New findings have found that Mpox (both clade I and clade II) can spread from human-to-human via sexual contact; however, Mpox can infect anyone if they had contact with someone with an active infection.

Mpox can spread through close, direct, physical contact with persons with active Mpox rashes. This transmission can occur with:

-  Salivary transmission

-  Anal, oral, or vaginal sex

-  Touching the genitalia or anus of a person who has Mpox

-  Hugging/kissing someone with Mpox.

Mpox is also known to spread zoonotically in endemic regions, most often through contact with wild animals such as squirrels, rats and mice.

The main form of prevention of Mpox infection is through:

-  Obtaining the 2-dose vaccination for Mpox

-  Safe sex practices such as:

-  Wearing a condom

-  Avoiding sexual relations and direct contact with anyone with active Mpox symptoms, such as a rash

-  Getting regularly tested for STDs and immediately visiting a healthcare provider to get tested for Mpox if you notice an unexplained rash anywhere on your body


Centers for Disease Control and Prevention. (2023, August 30). About Mpox. Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/mpox/about/index.html

World Health Organization. (2023, November 23). Mpox (Monkeypox)- Democratic Republic of the Congo. World Health Organization.https://www.who.int/emergencies/disease-outbreak-news/item/2023-DON493 

World Health Organization. (2023a). Mpox (Monkeypox) outbreak 2022. World Health Organization. https://www.who.int/emergencies/situations/monkeypox-oubreak-2022

 Chaitra Takle is a first year medical student at the John Sealy School of Medicine. 

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