Where Did Monkeypox Originate and How Do You Get It?

This month, more than 120 confirmed or suspected cases of monkeypox have been identified around the world in countries where the disease is not usually reported.

Monkeypox is a rare disease caused by the monkeypox virus, which is usually found in parts of Central and West Africa, particularly in areas of tropical rainforest.

While cases of the disease have been identified in countries outside Central and West Africa before, these have usually involved people who have traveled to the region.

The majority of the recent cases identified in non-endemic countries have occurred in Europe, mostly in Portugal, Spain and the United Kingdom. In fact, this latest cluster is the largest outbreak of the disease seen to date on the continent.

Monkeypox lesions
In this image, monkeypox-like lesions can be seen on the arm and leg of a female child in Bondua, Liberia, in 1971. Photo Courtesy of the CDC/Getty Images

The United States and Canada have also confirmed one and two cases respectively, although 20 more suspected cases have also been reported in the latter country, at the time of writing.

It is currently not known if the recent cases are linked and it is not clear how the individuals in question were exposed to the virus, with some having no history of travel to endemic regions.

Researchers are currently trying to understand more about the recent cluster of infections and how they occurred.

Monkeypox Origin

Monkeypox is a virus that is found in several animals, such as rope squirrels, tree squirrels, Gambian pouched rats, dormice, and non-human primates, among other species, and can be transmitted to humans.

The disease was first detected in the 1950s in laboratory monkeys, hence the name, although monkeys don't appear to be the main carriers of the virus. According to the World Health Organization, the first human case—a nine-year-old boy—was recorded in 1970 in the Democratic Republic of Congo (DRC).

Since then, the disease has spread to 11 countries across Central and West Africa, with the DRC particularity badly affected. The disease has also sporadically been reported outside Africa—with the first outbreak outside the region occurring in 2003.

How Do You Get Monkeypox?

The monkeypox virus can enter the body through broken skin, the respiratory tract, or mucous membranes, such as the eyes, nose, or mouth.

Animal-to-human movement can occur via a bite, scratch, direct contact with bodily fluids or lesion materials, or even the preparation of bush meat.

The virus does not tend to spread easily between people, and requires close contact with an infected person. Human-human transmission is mainly thought to occur via respiratory droplets, which cannot travel more than a few feet. As a result, prolonged face-to-face contact is usually needed for this to happen.

Between people, the virus can also be transmitted via direct contact with contaminated bodily fluids or lesion material, or indirect contact with lesion material, such as through bedding or clothing.

What Is The Incubation Period of Monkeypox?

The incubation period of monkeypox—the time it takes for someone to develop symptoms after infection—tends to be between seven and 14 days, but the interval can be anywhere from five to 21 days.

Scientists don't consider monkeypox to be contagious during the incubation period and there is no record of asymptomatic spread of the disease.

What Are The Symptoms?

The disease typically begins with flu-like symptoms, including fever, headaches, muscle aches, and severe lack of energy, accompanied by swelling of the lymph nodes.

Subsequently, the infected individuals can develop rashes—usually within one to three days of fever appearing. These tend to start on the face before spreading to other parts of the body.

These rashes progress in shape and character over the course of the disease. Initially, they start as macules (flat lesions less than one centimeter in size) before evolving into papules (slightly raised lesions,) then vesicles (lesions filled with clear liquid,) and lastly pustules (lesions filled with yellowish liquid.

After this, the lesions, which can number in their thousands, scab and eventually fall off.

Symptoms tend to last between two and four weeks, with the disease being self-limited—meaning one that resolves on its own with or without treatment.

Currently, there are no specific, widely available anti-viral therapeutics for the disease, with treatment focused on alleviating symptoms and managing complications, which can include secondary infections, sepsis and encephalitis.

Scientists have identified two main forms of the monkeypox virus: the West African clade and the Central African clade.

Both of these have the potential to cause severe illness in some cases, although the case fatality rate for the former is thought to be around one percent, whereas for the latter it could be as high as 10 percent, according to the World Health Organization.