Monkeypox is a rare viral disease that is found mostly in the rainforest countries of central and west Africa. The virus can spread to humans from an infected animal through an animal bite or direct contact with the animal's lesions or body fluids. Although it is much less infectious than smallpox, the disease also can be spread from person to person through large respiratory droplets during long periods of face-to-face contact or by touching body fluids of a sick person or objects such as bedding or clothing contaminated with the virus.

The disease is called "monkeypox" because it was first discovered in laboratory monkeys in 1958. The virus was identified in 1970 as the cause of a smallpox-like illness in humans in remote African locations.

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The disease first entered the United States in early June 2003, with the first human cases occurring in Illinois, Indiana and Wisconsin. The disease was spread to people by infected prairie dogs sold from a dealer in Villa Park, where prairie dogs and many exotic animals, including rodents from Africa, were housed together. Cases also have been reported in Missouri, Ohio and Kansas. There have been no human deaths related to this outbreak.

In humans, the signs and symptoms of monkeypox are similar to smallpox, but usually milder. About 12 days after people are infected with the virus, they may get a fever, headache, muscle aches and backache, swollen lymph nodes and a general feeling of discomfort and exhaustion. Within one to three days after development of a fever, they will get a rash. The rash typically develops into raised bumps filled with fluid. It often starts on the face and spreads to other parts of the body, but can originate on other areas of the body. The bumps go through several stages before they get crusty, scab over and fall off. A person is considered to be infectious to others until their lesions are crusted. The illness usually lasts for two to four weeks. If an exposed person does not develop signs or symptoms by the 21st day after the last exposure, they are unlikely to develop monkeypox.



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