Travelers should wear masks and take other precautions after the CDC raised its alert level for Monkeypox.

Since March, Monkeypox has spread across the globe out of Africa. The symptoms of monkeypox are similar to flu, but include a rash on the body and face. Severe scarring can be caused by painful lesions on the skin.

There have been cases of monkeypox reported in Europe, North America, South America, Africa, Asia, and Australia.

There were cases of men having sex with men. Some cases were reported in people who live in the same house.

Mutants continue to confuse scientists as they spread to more counties.

According to the CDC, there have been 21 Monkeypox cases in the U.S.

Test tubes labeled 'Monkeypox Virus Positive' are seen in this illustration taken on May 22, 2022. <span class=REUTERS/Dado Ruvic/Illustration" src="https://s.yimg.com/ny/api/res/1.2/du4i7H3l7IwTtHaORADcVA--/YXBwaWQ9aGlnaGxhbmRlcjt3PTcwNTtjZj13ZWJw/https://s.yimg.com/uu/api/res/1.2/sZYk7i.GsUJM_RDBqjwd9g--~B/aD0wO3c9MDthcHBpZD15dGFjaHlvbg--/https://media.zenfs.com/en/fox_news_text_979/69cd255d4f3f6bdd6aa949e1ca90e15c">
Test tubes labeled 'Monkeypox Virus Positive' are seen in this illustration taken on May 22, 2022. REUTERS/Dado Ruvic/Illustration

The disease may have gone undetected under the guise of an STD. There are many STDs that have the same symptoms as Monkeypox.

Major amplification events, like raves in Belgium, helped spread an endemic infectious disease from Africa into a social and sexual network.

Dr. Rochelle Walensky, director of Centers for Disease Control and Prevention gives an opening statement during a Senate Health, Education, Labor, and Pensions Committee hearing to examine the federal response to the coronavirus disease (COVID-19) and new emerging variants at Capitol Hill in Washington, D.C., U.S. January 11, 2022. <span class=Greg Nash/Pool via REUTERS" src="https://s.yimg.com/ny/api/res/1.2/a32ez44TrdY_jgxUOhVK0Q--/YXBwaWQ9aGlnaGxhbmRlcjt3PTcwNTtoPTQ3MDtjZj13ZWJw/https://s.yimg.com/uu/api/res/1.2/2ReUhfn.13.1_Dg57o.LpQ--~B/aD03MjA7dz0xMDgwO2FwcGlkPXl0YWNoeW9u/https://media.zenfs.com/en/fox_news_text_979/50473fb290efb6d8dbb58ef95de48735">
Dr. Rochelle Walensky, director of Centers for Disease Control and Prevention gives an opening statement during a Senate Health, Education, Labor, and Pensions Committee hearing to examine the federal response to the coronavirus disease (COVID-19) and new emerging variants at Capitol Hill in Washington, D.C., U.S. January 11, 2022. Greg Nash/Pool via REUTERS