Since the beginning of May, health authorities have identified 13 cases of monkeypox in three clusters across the UK and Portugal, and alongside Spain and the US, are tracking several dozen more people for potential signs of infection. A senior official from the US Centers for Disease Control and Prevention (CDC) said on Wednesday the agency has a “level of concern that this is very different than what we typically think of from monkeypox,” including that it could spread outside the United Kingdom.
What is monkeypox?
First identified by Danish scientists in 1958 as it spread among crab-eating macaque monkeys in captivity, monkeypox is a virus in the orthopoxvirus family. Other viruses in the same family include vaccinia, also called cowpox, and variola, also called smallpox. However, the virus has been found in a number of animals, including several other types of monkeys and rodents. It can also spread to humans, but humans are not the virus’ natural reservoir.
The virus stays dormant for between 5 and 21 days after infection. When symptoms appear, they include many of the same symptoms of smallpox, such as fever, headache, muscle aches, and the classic lesions that spread across the skin, fill with pus, and burst. However, unlike smallpox, monkeypox also causes the lymph nodes to swell.
Symptoms can persist for more than four weeks before recovery but often disappear after two. Scarring from the lesions is common.
How is it spread?
According to the CDC, “transmission of monkeypox virus occurs when a person comes into contact with the virus from an animal, human, or materials contaminated with the virus. The virus enters the body through broken skin (even if not visible), respiratory tract, or the mucous membranes (eyes, nose, or mouth).”
It can pass from animals to humans by a bite or scratch, or through the preparation of bushmeat, as well as direct contact with bodily fluids, lesion material, or through material such as clothing or bedding contaminated by contact with lesions.
Human-to-human transmission is also possible, but much less common, and is thought to occur primarily through large respiratory droplets, meaning close and prolonged face-to-face contact is required. The other methods of transmission mentioned above are also possible.
The first human case of monkeypox was identified in the Democratic Republic of the Congo in 1970 and thousands of cases have been tracked since then across several other African nations, including Cameroon, the Central African Republic, Côte d’Ivoire, Gabon, Liberia, Nigeria, Republic of the Congo, and Sierra Leone.
Is it deadly?
According to the World Health Organization (WHO), different variants of monkeypox have different virulence. In DR Congo, the virus is estimated to have a mortality rate of 10%, while in West Africa, it kills just 1% of those infected. Unlike with many other illnesses, children experience worse symptoms and higher death rates than adults.
However, in recent outbreaks, the mortality rate has been even less: an outbreak in the US in 2003 saw 71 people catch the virus, none of whom died as a result. In Nigeria, at least 183 cases were tracked across several states between 2017 and late 2019, with nine deaths.
How is it treated?
There is no treatment for monkeypox illness. Because of its close relationship to smallpox and its discovery in humans during a smallpox inoculation program, researchers believe the smallpox vaccine can protect against monkeypox as well. Jynneos, a vaccine made by Bavarian Nordic, is licensed in the United States to be administered to adults for both viruses.
Smallpox was eradicated in 1980 thanks to a global vaccination campaign, so only a small number of people alive have received a smallpox vaccination, such as select groups in the US military and scientists who directly handle vaccine samples in laboratory conditions.