It is a deadly relative of smallpox and was unknown before 1958. Today, MPOX, formerly known as monkeypox, is spreading across Central Africa, including in countries where it has never been seen before, and is a global health emergency.
“Parts of Africa are currently experiencing a surge in monkeypox virus infections, along with the spread of a new sexually transmitted strain of the virus. This is an emergency not just for Africa, but for the entire planet,” World Health Organization director-general Dimier Ogoyena said in a statement. “The monkeypox virus originated in Africa, was ignored there and led to a global pandemic in 2022. It is time to take decisive action to prevent history from repeating itself.”
The Democratic Republic of Congo has recorded a record number of suspected MPOX cases in a single year, with over 15,600 cases and 537 deaths. Worryingly, MPOX has spread to neighbouring countries not previously affected by the disease, including Burundi, Kenya, Rwanda and Uganda, which has prompted the World Health Organization to declare it a Public Health Emergency of International Concern.
But what exactly is MPOX, and why are these outbreaks worrying experts more than other recent epidemics? Here’s what you need to know.
What is MPOX and is it fatal?
Mpox, until recently known as monkeypox, is a relative of smallpox that is much milder and less contagious. Both are orthopoxviruses, a genus of 12 DNA viruses that also includes cowpox and camelpox. According to the WHO, it is characterised by a painful rash, swollen lymph nodes and fever.
There are two distinct genetic clades, or variants, Bernard Moss, a virologist at the National Institute of Allergy and Infectious Diseases (NIAID), explained in a 2022 interview: clade I, which is responsible for the current outbreak, kills 1 in 10 people who are infected; clade II, which is responsible for the 2022 outbreak, has a much lower case fatality rate, less than 1%.
The current outbreak has been declared an emergency due to the emergence of a new version of the virus, called lineage Ib, which may be more severe and contagious. Children appear to be particularly vulnerable, with the majority of infections and deaths in the Democratic Republic of the Congo occurring among those under 15 years of age.
Mpox is a zoonotic disease transmitted from animals to humans. The original name of the virus, first discovered in monkeys in a Danish laboratory in 1958, may have been a misnomer. The virus is endemic in African rainforests and is thought to be carried by small mammals, but it can infect many mammals and has only been isolated twice from wild animals: in grey squirrels in the Democratic Republic of Congo in 1985 and mangabeys in Côte d’Ivoire in 2012. The actual reservoir of the disease is unknown.
(What are zoonotic diseases? Where do they come from?)
Most cases have occurred in West and Central Africa since a boy was diagnosed in the Democratic Republic of Congo in 1970. Rosamund Lewis, technical lead for MPOX at the WHO, told National Geographic in 2022 that early on, most cases were “spillover infections,” acquired from hunting or slaughtering infected wild animals.
How does mpox spread?
Both types of MPOX can be spread by direct contact with infected animals or contaminated materials, including items such as clothing, bedding and towels.
The virus can also spread from person to person through close contact, such as through respiratory droplets spread through kissing, talking to an infected person, or direct contact with infected skin or oral or genital lesions.
The rash is a contagious “little virus factory,” says Andrea McCollum, an epidemiologist at the US Centers for Disease Control and Prevention. The incubation period ranges from three to 17 days, and people with MPOX symptoms are contagious “until the rash has completely healed and a new layer of skin has formed,” according to the CDC.
(Are pets at risk for monkeypox?)
But until recently, the virus rarely spread beyond a few households in a community. Though the disease was characterized at least 52 years ago, “the reality is we don’t know as much as we’d like to,” Lewis said.
Is it a sexually transmitted disease?
The 2022 MPOX epidemic disproportionately affected gay men, making it difficult for public health officials to educate the public without stigmatizing that community.
David Heymann, a longtime WHO infectious disease expert, told The Associated Press at the time that sexual activity at raves in Spain and Belgium was likely a factor in the spread of the virus, seeding the events internationally in the same way that large gatherings helped spread COVID-19 earlier in the pandemic.
But evidence shows MPOX is not sexually transmitted, Moss said. Symptomatic people can catch it through skin-to-skin transmission, including sexual contact, and through contact with sheets, towels and clothing.
Past outbreaks in Africa have infected women, children and men of all ages. “There’s no prevention, and this virus doesn’t necessarily remain in one gender or one population,” warned Anne Limoine, an infectious disease epidemiologist and professor at the University of California, Los Angeles School of Public Health.
Public education is key. “We don’t want people to be worried, but they need awareness to protect themselves,” Lewis adds. “What we need is for each person to know their own risk and manage it.”
Can I get tested or vaccinated?
Tests for mpox already exist and involve swabbing the lesions, and the CDC only recommends testing if you have a rash that looks like mpox.
There are currently two vaccines available for mpox, both of which are recommended by the WHO Strategic Advisory Group of Experts on Immunization, and the U.S. Department of Health and Human Services has encouraged people at high risk to get vaccinated, ensuring they receive both doses of the two-dose Jynneos vaccine.
The good news is that people who are already fully vaccinated or who have previously been infected with clade II mpox “are expected to be protected from severe disease caused by clade I mpox.”
But the Associated Press reports that vaccines are not widely available in African countries, which are the most vulnerable to the outbreak. By declaring a “public health emergency of international concern,” the WHO is legally empowered to make recommendations to member states on how to respond to the outbreak, and it also mobilizes funding and political support.
