Where Does Monkeypox Get Its Name From?

Monkeypox is a rare disease caused by the monkeypox virus, which is usually found in parts of Central and West Africa—particularly in areas where there is tropical rainforest. But where does this disease get its name?

The monkeypox virus belongs to the same family as the pathogen that causes smallpox—one of the most devastating diseases known to humanity that resulted in millions of deaths before a successful global vaccination campaign helped to eradicate it.

Monkeypox is less contagious than smallpox and causes less severe illness, according to the World Health Organization, although in a small proportion of cases it can result in serious disease. It's zoonotic, meaning it can be transmitted from animals to humans.

How Did Monkeypox Get Its Name?

The monkeypox virus is found in several wild animals, such as rope squirrels, tree squirrels, Gambian pouched rats, dormice and non-human primates, among other species.

It was first identified after two outbreaks in 1958 of a pox-like disease among lab monkeys in Denmark—hence the name—although monkeys don't appear to be the primary carriers of the virus.

"The virus was discovered before the human disease in laboratory monkeys in Denmark who had a typical rash," Daniel Bausch, president of the American Society of Tropical Medicine and Hygiene, told Newsweek.

"This gave rise to the name of the virus and disease, which actually turns out to be a misnomer, because monkeys are likely just like humans—an unlucky dead-end host that occasionally gets infected, but is not part of the maintenance of the virus in nature," he said.

Small mammals in West and Central Africa likely serve as the natural reservoir, according to Bausch.

"Interestingly, the monkeys in the lab in Denmark were imported from Singapore, not Africa, and there is no evidence to suggest that monkeypox is maintained in nature anywhere outside of Africa," he said.

"However, the traffic of non-human primates for lab use is worldwide and complex. It is entirely possible that these primates from Asia were housed at some point with animals from Africa, where presumably transmission took place."

Following the outbreak in Denmark, further cases of the disease were detected outside of Africa in the late 1950s and early 1960s among captive monkeys in the U.S. and giant anteaters at a zoo in Rotterdam, the Netherlands. It is suspected that the anteaters had contracted the virus from previous contact with monkeys elsewhere.

When Was the First Human Case?

The first human monkeypox case was reported in 1970—a nine-year-old boy in Basankusu, Équateur Province, of the Democratic Republic of the Congo (DRC.)

Since then, human cases have been steadily increasing in the DRC, and have been reported in several other African countries, including Benin, Cameroon, the Central African Republic, Gabon, Cote d'Ivoire, Liberia, Nigeria, the Republic of the Congo, Sierra Leone and South Sudan. The majority of infections have occurred in the DRC.

Outside of Africa, cases of monkeypox in humans have been rare. When they have occurred, these cases have usually involved people who traveled to endemic regions or came into contact with imported animals.

However, multiple cases of the disease have been identified in several non-endemic countries over the course of 2022, including the United States. Many of these cases have had no established travel links to endemic areas.

The first known human case outside of Africa was reported in 2003—a three-year-old girl who had been hospitalized in central Wisconsin after being bitten by a prairie dog. It is thought that rodents imported from Ghana infected native prairie dogs, which then went on to transmit the disease to around 40 people.

A crab-eating macaque monkey and monkeypox virus
A file photo of a crab-eating macaque monkey (left) and a 3D rendering of the monkeypox virus. Monkeypox was first detected in lab monkeys in the 1950s. iStock