Monkeypox is a disease that causes fever, chills, swollen lymph nodes, and skin lesions. Its cause, the monkeypox virus, is related to the smallpox virus. However, it is much less severe.

Most people who contract monkeypox make a full recovery within 3–4 weeks. However, it can be a more serious illness for some people and potentially result in death.

Monkeypox virus is endemic to West and Central Africa, but outbreaks can also happen elsewhere. In May 2022, monkeypox outbreaks occurred in several countries in Europe and North America.

The virus transmits through close contact with a person or animal that carries the monkeypox virus. It can also occur via contact with a contaminated object, such as towels or bed sheets.

Keep reading to learn more about the symptoms of monkeypox, its origins, transmission, treatment, and prevention.

close up of monkeypox through a microscope, and hand scratching the other handShare on Pinterest
Smith Collection/Gado/Madrolly/Getty Images

Monkeypox is a viral illness. Its cause — monkeypox virus — is a type of orthopoxvirus. This group of viruses also includes cowpox and smallpox. However, monkeypox has a much lower death rate than smallpox.

There are two broad subtypes of the monkeypox virus: the Central African clade and the West African clade. A “clade” is a group of viruses that share similar DNA. Of the two, the West African clade appears to be milder.

Monkeypox symptoms tend to progress similarly from person to person. First, flu-like symptoms appear, such as:

It is important to note that, in some cases, people do not experience a fever.

Following the onset of the initial symptoms, a rash develops within around 1–3 days. This frequently starts on the face and then spreads to other parts of the body.

The rash consists of skin lesions that progress through the following stages before falling off:

  • macules, flat discolored areas
  • papules, small raised areas of swelling
  • vesicles, small fluid-filled blisters
  • pustules, small blisters that contain pus
  • scabs, crusts that form over the rash

Monkeypox symptoms can take some time to appear after a person contracts the virus. The time between acquiring the virus and developing symptoms is known as the incubation period.

The incubation period for monkeypox can be fairly long. Typically, it is 7−14 days, but it can range from 5−21 days.

Most people who get monkeypox get better on their own without treatment in a few weeks. However, the disease can have serious consequences for some individuals, including death. Other complications may include:

The mortality rate from monkeypox depends on which type of monkeypox virus a person has. While the West African clade has a death rate below 1%, the Central African variety has a death rate of up to 11% in unvaccinated children. The remainder usually fully recover within 4 weeks of the onset.

Some people are more vulnerable to serious disease from monkeypox than others. Dr. Martin Hirsch, professor of medicine at Harvard University and infectious disease expert, told Medical News Today that “monkeypox appears to be more severe in children, young adults, and the immunocompromised.”

Pregnant people may also be more vulnerable to monkeypox. Older adults who received a smallpox vaccine when they were younger may have some protection against the virus.

Doctors and public health officials may have differing opinions about whether monkeypox could become a pandemic.

On May 30, 2022, Dr. Rosamund Lewis from the World Health Organization (WHO) stated that they did not think that the outbreak could become a pandemic and were not concerned about this possibility at present.

The Vaccine Alliance, Gavi, lists monkeypox as one of the infections that may become pandemic. However, there are some important differences between the monkeypox virus and the COVID-19 pandemic. Dr. Hirsch explained:

“We have vaccines and antivirals and early recognition diagnostic methods that will make a pandemic far less likely. Moreover, monkeypox virus is relatively well-characterized and far less likely to mutate rapidly than RNA viruses like HIV, influenza, or SARS-CoV-2.”

“Previous outbreaks, such as the 2003 one traced to importation of rodents from Africa and subsequent transmission to prairie dogs and humans, have been relatively quickly controlled without setting off large epidemics or pandemics.”

Monkeypox outbreaks in the U.S.

Historically, there have not been many outbreaks of monkeypox in the U.S, according to the CDC. The first happened in 2003 when rats from Ghana infected prairie dogs that people bought as pets in the Midwest. This resulted in 47 human cases.

In 2021, two cases of monkeypox infection involved individuals who had traveled from Nigeria to the U.S.

In May 2022, an American resident returning from Canada tested positive for monkeypox, resulting in transmission of the virus to others. Unlike other outbreaks, the 2022 cases do not have links to direct travel in West or Central Africa or to the pet trade. At the time of writing, it is unclear how people became exposed to the virus.

The CDC also reports that scientists first discovered the monkeypox infection in 1958, when two outbreaks occurred in monkey colonies that they kept for research. Initially, the virus only affected animals.

The first known case of monkeypox in humans occurred in the Democratic Republic of Congo (DRC) in 1970. Since then, the monkeypox virus has become endemic to certain countries in West and Central Africa. “Endemic” means that the virus is common in the population but within a specific location.

The virus is most prevalent in areas near tropical rainforests. The DRC has the most cases, reporting more than 1,000 cases per year since 2016. The virus is less prevalent in Nigeria, but it was the location of an outbreak between 2017–2019, which affected 300 people.

In May 2022, the WHO reported 92 lab-confirmed cases and 28 suspected cases of monkeypox infection in nonendemic countries. These included:

  • United Kingdom
  • Spain
  • Portugal
  • Canada
  • U.S.
  • Australia
  • Belgium
  • France
  • Germany
  • Italy
  • Netherlands
  • Sweden

Monkeypox spreads through close contact with an animal or human that carries the monkeypox virus.

Animal-to-human transmission can occur in people who interact with animals from West or Central Africa or those involved in the exotic pet trade. A person can contract the monkeypox virus via:

  • an animal scratch or bite
  • bush meat preparation
  • direct contact with lesions or body fluids from animals
  • indirect contact with objects that have viral contamination from animals

Human-to-human transmission can also occur via direct or indirect contact with the virus. Direct contact might occur via exposure to:

  • skin lesions
  • large respiratory droplets, which come from coughs or sneezes
  • other bodily fluids

Indirect contact might occur via exposure to objects a person with the virus has touched, such as bedding or towels.

The virus may enter the body through broken skin or via mucous membranes. These include the membranes inside the mouth, nose, or eyes.

Scientists are not sure which method of transmission is the most common among humans, but experts believe large respiratory droplets are one of the main routes.

However, unlike other viruses that spread through respiratory droplets, the monkeypox virus transmits via big droplets. Due to their size, these droplets cannot travel as far through the air as those carrying SARS-CoV-2, the virus that causes COVID-19.

Monkeypox virus droplets do not usually travel farther than a few feet through the air. This means prolonged face-to-face contact is necessary to contract the disease this way.

Is monkeypox a sexually transmitted infection (STI)?

In the May 2022 outbreak of monkeypox, a number of cases affected men who have sex with men. This led some people to question if the monkeypox virus was an STI or whether it especially affects members of the LGBTQIA+ community.

Current evidence indicates that this is not the case. Any kind of close physical contact between any people can spread monkeypox, whether the contact is sexual or not.

Researchers have not yet found any cures for monkeypox infection, so medical intervention consists of symptom management.

For people with mild symptoms, a doctor may suggest rest and staying hydrated until the infection resolves. In more serious cases, doctors may use antiviral drugs.

Animal and test-tube studies show that cidofovir (Vistide) and brincidofovir (Tembexa) have activity against orthopoxviruses. Despite this positive finding, doctors are unsure whether they may help a person with severe monkeypox.

Another potential treatment for those with weakened immune systems is vaccinia immune globulin (VIG). This has no proven benefit for a person with smallpox, so researchers do not know if VIG may help someone with monkeypox.

Preventing the spread of monkeypox may involve several key elements.

Vaccines

Previous data suggest that the smallpox vaccine is at least 85% effective in preventing monkeypox infection. However, research on this is still ongoing. Dr. Hirsch told MNT:

“Smallpox vaccines and modified smallpox vaccines appear effective in monkeypox animal models but have not been studied in controlled trials against monkeypox in humans.”

On the subject of how long vaccine protection might last, he added: “Smallpox vaccines provide long-term immunity against smallpox and, presumably, against monkeypox.”

In the U.S., a licensed vaccine known as Imvamune, Imvanex, or JYNNEOSTM is available to prevent smallpox or monkeypox. Only people who are living in areas where they may become exposed to monkeypox need the vaccine. People serving in the military may also need to get the smallpox vaccine if their deployment will involve them traveling to certain areas.

Containment measures

The CDC monitors monkeypox outbreaks closely, keeping track of cases and taking action to prevent the spread of the virus. They:

  • conduct laboratory testing
  • administer smallpox vaccinations and other treatments
  • track animals that may have monkeypox virus
  • issue guidance to patients, healthcare professionals, and animal handlers

According to Dr. Hirsch, “The precautions used in medical centers for known monkeypox exposure appear highly effective in limiting spread.”

Hygiene measures

A person can reduce their risk of getting monkeypox by avoiding contact with:

  • those who may have monkeypox
  • their bedding or other objects they have touched
  • sick or dead animals in areas where monkeypox occurs

If a person does come into contact with a person or animal that may have monkeypox, they should follow general hygiene precautions, including:

  • Hand hygiene: Wash the hands thoroughly with soap and water, or use an alcohol-based hand sanitizer. This is especially important before and after eating, after using the bathroom, and after handling soiled clothing or laundry.
  • Cleaning surfaces and objects: Clean items the person or animal has touched or used with disinfectant. This might include kitchen or bathroom surfaces, door handles, and phones or devices.
  • Laundry: Handle soiled laundry with care, using gloves to prevent direct contact. Wash at a typical temperature with detergent. It is not necessary to add bleach. Avoid shaking soiled laundry, as this might spread particles that contain the virus.
  • Not sharing personal items: Do not share cutlery, plates, and other personal items. Wash eating utensils with hot water and soap, or in a dishwasher.

Where possible, those with confirmed monkeypox should limit contact with other family members and pets. They should also abstain from sexual activity until any skin lesions have completely healed.

Anyone who may have symptoms of monkeypox should contact a medical professional, particularly if they:

  • have traveled to an area where there is monkeypox
  • have been in contact with a person with confirmed monkeypox
  • work with animals that may have monkeypox

Men who have sex with men should also contact a medical professional if they develop symptoms. If lesions appear around the genitals, they can appear similar to other STIs – it is important to consult a doctor to determine the cause.

It is best for people to contact a doctor via telephone rather than visiting in person unless they say otherwise.

Monkeypox is a viral illness that begins with flu-like symptoms and later causes a distinctive rash. Most people who contract monkeypox recover with no serious complications, but it can be a serious disease for some individuals.

Monkeypox is endemic in West and Central Africa, but most cases are from the Democratic Republic of the Congo. However, outbreaks do occur in other locations. in May 2022, outbreaks happened in Europe, Australia, and North America.

The virus that causes monkeypox is similar to the smallpox virus. This means smallpox vaccines can help prevent people from acquiring it. There is no proven treatment for monkeypox, so preventing the spread is vital for controlling outbreaks.