The Trouble with Mpox
Origins and Basics
Mpox (formerly known as monkeypox) is a viral illness that belongs to the same family as smallpox. First identified in Denmark in 1958 among two colonies of monkeys kept for research, mpox was found in humans in 1970 in what is now the Democratic Republic of the Congo (DRC). Until 2022—when a global outbreak spread the virus to more than 118 countries—most cases that occurred outside of west and central Africa were travel-related or spread by animal importation.
Mpox causes painful skin lesions that persist for two to four weeks and can cause scarring. Before the rash appears, some people experience fever, swollen lymph nodes, muscle pain, headache, and a general feeling of illness. Although most people experience a few weeks of discomfort, cases can be very serious or asymptomatic. People who are pregnant, under the age of one, or immunocompromised are prone to more severe cases. Of the two types of mpox, the one involved in the U.S. outbreak (clade II) is less severe and rarely results in death. The other type (clade I) can have a death rate of up to 10 percent.
Transmission primarily occurs via prolonged, direct contact with an infected person’s skin lesions or bodily fluids. In some cases, the infection can spread from person to person before symptoms occur or while a person is asymptomatic. Treatment typically involves pain management and wound care.
Although not 100 percent effective at preventing infection, the mpox vaccine—given in two doses at least 28 days apart—can reduce symptom severity and duration.
The 2022 Global Mpox Outbreak
The 2022 mpox outbreak caused more than 102,000 cases and 220 deaths globally. At its peak, the United States saw more than 11,000 monthly cases; counts have remained below 250 since October 2023.
While Americans of all ages, genders, and sexual orientations were affected by mpox, most cases occurred among men who have sex with men (MSM). Because vaccine doses were limited, vaccination efforts focused on MSM—especially those with additional risk factors. Evidence suggests that vaccination was key to decreasing transmission; however, the MSM community also practiced harm reduction strategies that likely averted 25 percent of potential cases.
A New, Deadlier Variant
Although mpox is still a problem in many places, the DRC and surrounding countries are at the epicenter of the outbreak. Additionally, a new and more deadly mpox variant has emerged, with children representing the majority of cases. In August 2024, the World Health Organization declared the outbreak a public health emergency of international concern (PHEIC)—an extraordinary event with the potential to spread beyond a nation’s borders and require swift international action.
Why We Should Be Concerned
More than 40 new infectious diseases have been documented in humans since the 1970s, and the number of disease outbreaks each year is trending upward. People, animals, agricultural products, and other goods move easily around the globe, and pathogens move with them. Warming climates, encroachment on wilderness spaces, and more densely populated living conditions exacerbate this. Add aging populations (especially in high-income countries), increases in chronic disease, unequal access to healthcare, and misinformation and/or distrust of medical systems, and suddenly almost every facet of modern life supports increased disease transmission. In an ever more connected society, communicable diseases cannot be contained to one geographic area.
There are also a few more specific concerns about mpox. First, the current outbreak in the DRC shows that the virus is evolving. The more bodies a virus infects, the more opportunities it has to replicate and acquire characteristics that improve its ability to spread. Viruses can change in many ways—including infectiousness, severity, and symptomatology—but the newest type of mpox appears to have become more severe and more infectious. Second, the U.S. population has many characteristics that can increase the severity of an outbreak. An aging population in which 42 percent of adults have two or more chronic health conditions and 22 percent of people live in a designated primary care professional shortage area increases America’s susceptibility to infectious diseases. Last, what happens abroad often finds its way to the United States—and mpox has already done so once.
The Trouble with Mpox
In the United States, mpox was mainly characterized as a sexually transmitted infection (STI) affecting MSM. While there is a lot of truth in this perspective, it is also somewhat problematic. First, experts are debating defining mpox as an STI. Although live mpox virus has been found in semen, it is currently unknown if the infection can spread via semen or vaginal fluid alone. The same is true for blood. Mpox primarily spreads by direct contact with skin lesions, which can occur anywhere on the body, including inside the mouth, throat, anus, and vagina. While mpox can (and often does) spread through sexual contact, this is not the exclusive—and perhaps not the primary—way it is transmitted. Thus, classifying mpox as an STI has both benefits and challenges.
Because sexual contact has been a main driver of mpox transmission in the United States, the term STI is appropriately descriptive. However, STIs are highly stigmatized, which can deter people from seeking treatment and disclosing their illness to partners. Also, since sex is often defined by penetration, people may not understand that they can get mpox from other activities like kissing, cuddling, or sharing bedding. This means that condoms and some other traditional STI prevention tools may not prevent infection.
Second, although most American mpox cases occurred among MSM, this is not the case globally—and if the new variant makes its way to the United States, it could take hold among people of all ages, genders, and sexual orientations. While health communication focusing on communities at the highest risk makes sense, it can also have unintentional, harmful effects. Strongly associating mpox with specific communities can increase stigma, especially for those already marginalized. It can also lead members of non-targeted groups to underestimate their risk.
Although mpox cases are currently low in the United States, it is vital to prepare for the possibility of increased transmission. Whether in preparation or response, accurately communicating how mpox spreads and can be prevented is key to helping people protect themselves. Thoughtful messaging that avoids unintentional stigma and empowers communities to reduce risks in ways that work for them must be at the forefront of the U.S. mpox response.