Understanding Mpox: What You Need to Know

By: Dr. Rashid Chotani, Chief Medical Director, IEM Health

Staying ahead of emerging health threats is not just important – it is essential for our collective well-being. One such threat that is making headlines is mpox, formerly known as Monkeypox. While it may sound like a distant concern, mpox is a serious viral infection that requires our attention, especially in the context of safeguarding public health and safety. Understanding this disease and taking proactive measures can make a difference in preventing its spread and protecting our communities.

What is Mpox?

Mpox is a rare viral disease that belongs to the same family of viruses that causes smallpox. Although it is less severe than smallpox, mpox can lead to significant illness, particularly among vulnerable populations. Discovered in Denmark, in1958 after two outbreaks in research monkey colonies, hence the former name “monkeypox.” [1] The disease made its first appearance in a nine-year-old boy in 1970, in the Democratic Republic of the Congo. [2] Following the eradication of smallpox in 1980 and the end of smallpox vaccination worldwide, mpox has steadily emerged in central, east, and west Africa.

The first reported cases of mpox in the United States was in 2003, from an outbreak involving 71 patients in six Midwestern states linked to a shipment of animals from Ghana and West Africa to a pet store in Texas. [3] There were also travel-associated cases in July and November 2021 in Maryland. [4] On May 7, 2022, public health experts learned that there may have been mpox in the United Kingdom, after several years with no verified cases of the disease in non-endemic nations. Since then, cases have been reported from Sweden and Australia to the United States and Canada, causing a global outbreak in 2022-2023. Mpox reached the United States as part of this outbreak in 2022, resulting in 32,000 known infections and 58 deaths.

Current Outbreak

There are two distinct types of mpox, clade I (subclades Ia and Ib) and II (subclades IIa and IIb). To date, in the United States, all cases are linked to the less virulent and contagious clade II. According to the Centers for Disease Control and Prevention (CDC), no clade I infections have been found in the United States, and there is low risk of this strain arriving.

U.S. wastewater surveillance systems are in place to detect mpox activity and track its spread through communities. The most recent surveillance has demonstrated exceptionally low detection with only two sites in California yielding positive results. Within these two sites, the detection level was extremely low. [5] According to the CDC, 1,122 cases of clade II mpox have been reported in the United States in 2024, with most of the new cases in people from higher-risk groups who have not received two doses of the mpox vaccine.

However, the global outbreak that began in May 2022 is ongoing.

On August 14, 2024, the World Health Organization declared mpox a public health emergency of international concern. As of mid-2024, over 120 countries have reported mpox. Between January 2022 and August 2024, over 100,000 laboratory-confirmed cases and over 220 deaths among confirmed cases have been reported globally. [6] Currently, mpox clade Ib and clade II are causing epidemics in multiple nations.

Despite its rarity, understanding mpox is vital as it continues to pose a risk to global health. At present U.S. is at low risk as only clade II has been detected in confirmed cases and wastewater surveillance. However, globally both clade Ib and clade II are causing epidemics. More work needs to be done immediately on both clade Ia and Ib to better understand the transmission routes, especially involving children, and severity of the new clade Ib in particular. While vaccines are available, they are only a part of the response. There are still a lot of gaps in understanding the complete spectrum of the disease and response strategies, including more research, education, increased surveillance, diagnostics, and therapeutics are needed.

How is Mpox Transmitted?

Human-to-human transmission happens through close, personal contact, including direct skin-to-skin contact with mpox rash or scabs, respiratory droplets during prolonged face-to-face contact, direct contact with body fluids, or contaminated materials like bedding. Case trends demonstrate that mpox spreads most frequently among men who have sex with men, a group that includes people who identify as gay, bisexual, transgender and nonbinary. Pregnant women with mpox can pass the virus directly to the fetus during pregnancy or to a newborn during and after birth.

While mpox is not as contagious and less transmissible through the air as viruses like COVID-19 or the flu, it is important to recognize that it can still spread in close-contact settings.

Understanding how mpox transmits and taking appropriate precautions are key to preventing outbreaks, especially in environments where people are in close proximity.

Symptoms to Watch For

The incubation period for mpox is usually 7 to 14 days, although it can range from 5 to 21 days. The disease typically begins with symptoms, including:

  • Fever
  • Headache
  • Muscle aches
  • Backache
  • Swollen lymph nodes
  • Chills
  • Exhaustion

Within 1 to 3 days (sometimes longer) after the appearance of fever, the patient develops a rash, often beginning on the face and then spreading to other parts of the body. The rash goes through different stages before finally forming scabs, which later fall off.

While there is no specific treatment for mpox, supportive care and symptom management are crucial.

Prevention and Management

There are steps you can take to limit your exposure and protect yourself and others from mpox. The CDC recommends the following preventative measures:

  • Avoid close, skin-to-skin contact with individuals who have a rash that looks like mpox or animals that carry the mpox virus (e.g., small rodents, monkeys, and other mammals that live in areas where mpox has been found).
  • Get vaccinated. Check with your healthcare provider to see if the mpox vaccine is recommended for you.

Learn more about the health effects of mpox, and vaccine information by visiting the CDC’s website.

[1] B.L. Ligon, Monkeypox: a review of the history and emergence in the Western hemisphere. Seminars in Pediatric Infectious Diseases, Elsevier, 2004.
[2] N. Erez, et al., Diagnosis of imported monkeypox, Israel, 2018, Emerg. Infect. Dis. 25 (5) (2019) 980.
[3] Rashid A. Chotani, Monkeypox Outbreak in the US; https://sites.pitt.edu/~super1/lecture/lec10651/001.htm. June, 2003.
[4] Imported Monkeypox from International Traveler, Maryland, USA, 2021. Varea Costello et al., Emerg Infect Dis. 2022 May; 28(5): 1002–1005.
[5] U.S. Mpox Wastewater Data. Updated August 21, 2024. https://www.cdc.gov/nwss/wastewater-surveillance/mpox-data.html
[6] WHO. https://www.who.int/news/item/14-08-2024-who-director-general-declares-mpox-outbreak-a-public-health-emergency-of-international-concern.