The United States and World Health Organization have declared a public health emergency after the monkeypox outbreak has spread to the U.S. and more than 70 other countries. Here's what you need to know about the illness.
What is monkeypox?
Monkeypox is a virus that originates in wild animals such as rodents and primates, and occasionally jumps to people. It belongs to the same virus family as smallpox. Most human cases have been in central and west Africa, and outbreaks have been relatively limited.
Scientists first identified the illness in 1958 when there were two outbreaks of a "pox-like" disease in research monkeys — thus the name monkeypox. The first known human infection was in 1970, in a young boy in a remote part of Congo.
What are the symptoms and how is it treated?
Most monkeypox patients experience only fever, body aches, swollen lymph nodes, chills and fatigue. People with more serious illness may develop a rash and lesions on the face and hands that can spread to other parts of the body. The lesions, which can resemble pimples, tend to start out flat and then rise up but with an indented center. Symptoms typically develop about 12 days after exposure, but they may appear as soon as five days or up to 21 days after exposure.
Most people recover within about two to four weeks without needing to be hospitalized, but monkeypox can be fatal in up to 6% of cases and is thought to be more severe in children.
Smallpox vaccines are effective against monkeypox, and anti-viral drugs are also being developed.
How is monkeypox spread?
Transmission has typically occurred from animal to person in regions of Africa where monkeypox is endemic, but the virus this year started spreading from person to person. In humans, the virus is most commonly spread by direct contact with body fluids or skin lesions. It can also be spread by contact with contaminated clothing, bedding, towels or other objects used by an infected person, health officials say. Transmission may occur via respiratory droplets, but it is believed to be rare and requires extended contact of more than four hours with droplets from an infected person, according to the Mayo Clinic.
In the U.S. and Europe, the vast majority of infections have happened in men who have sex with men. However, health officials have stressed that anyone can catch the virus, and they want to stop transmission before it spreads broadly and reaches high-risk groups, such as the elderly.