Mpox

Mpox, formerly called monkeypox, is a viral disease that affects animals and human beings. Scientists first isolated and identified the mpox virus from laboratory monkeys in 1958. They obtained it from monkeys that had an unusual rash of skin pustules (small bumps filled with fluid). Historically, such pustules were called pox. Rats, squirrels, and mice also can carry mpox. The disease is uncommon in human beings. The first human case of mpox was not recorded until 1970.

People who eat or get bitten by infected animals can catch mpox. The virus does not spread easily from person to person. However, someone who has close contact with an infected person can become ill with mpox. Touching an infected person’s rash, scabs, or body fluids can spread the disease.

Symptoms

of the disease develop about two weeks after a person is exposed to the mpox virus. Symptoms include fever, headache, muscle pain, backache, and swelling of lymph nodes. Following the fever, a rash appears on the face and other parts of the body. The rash develops into fluid-filled pustules, which dry up and fall off. The illness lasts from two to four weeks. In Africa, up to 10 percent of people infected with mpox may die from the disease.

Diagnosis.

Physicians suspect mpox if a person shows the symptoms and has had contact with an infected person or animal. Laboratory tests are used to detect the mpox virus in samples from blood, pustules, or scabs of patients.

Prevention.

People can prevent infection by not handling wild animals that may carry the virus. They should also avoid skin-to-skin contact with people infected with mpox. The United States Centers for Disease Control and Prevention (CDC) states that although the risk of catching mpox in the United States is low, anyone who develops a rash that resembles mpox should see a doctor.

The mpox virus is related to the virus that causes smallpox. Smallpox vaccine can protect against mpox when it is given before a person is exposed to the virus. Smallpox vaccination given after exposure to mpox may help prevent the disease or make it less severe. However, because the disease is uncommon, health officials do not recommend widespread smallpox vaccination to protect people from mpox.

Outbreaks.

Mpox occurs naturally among wild animal populations of central and western Africa. Since the 1970’s, it has caused occasional outbreaks of illness among people in central Africa. Mpox rarely infected people in western Africa until the 2010’s. Historically, most cases of mpox outside central and western Africa were found in travelers who had visited those regions.

In 2003, 71 people in the United States became ill with confirmed or suspected cases of mpox. They caught the disease after handling prairie dogs that were purchased at a pet shop in Illinois. Prairie dogs do not naturally carry the mpox virus. The animals became infected at the pet shop, where they were housed with a rodent called a Gambian pouched rat that carried the virus. An animal dealer had imported the rat from Africa to sell it as a pet.

Several people were hospitalized in the 2003 outbreak, but there were no deaths. Physicians and veterinarians quickly quarantined (isolated) people and animals that might have been exposed to the virus. This action was designed to prevent the disease from spreading to other people, pets, or wild animals. Following the outbreak, the CDC and the Food and Drug Administration (FDA) banned the importation of rodents from Africa.

A far larger outbreak of mpox began in 2022. The disease spread from person to person in Europe and North America. More than 94,000 people contracted mpox, including about 32,000 people in the United States. However, very few deaths were reported. The symptoms of mpox were less severe than in previous outbreaks. Some health experts think the mild symptoms contributed to the spread of the illness, because people with such symptoms may not realize they are sick. People who do not know they have mpox may not take precautions to prevent spreading the virus to others.