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Medical Author:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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Medical Editor:

Mary D. Nettleman, MD, MS, MACP

Mary D. Nettleman, MD, MS, MACP

Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.

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In this Article

• Monkeypox facts
• What is monkeypox?
• What is the history of monkeypox?
• What causes monkeypox? How is monkeypox transmitted?
• What are risk factors for monkeypox?
• What are monkeypox symptoms and signs?
• How is monkeypox diagnosed?
• What is the treatment for monkeypox?
• What is the prognosis of monkeypox?
• Can monkeypox be prevented?
• Where can people get more information about monkeypox?
• What research is being done on monkeypox?
• Monkeypox Index

Monkeypox is caused by an Orthopoxvirus named monkeypox. The viruses are oval brick-shaped viruses that have a lipoprotein layer with tubules or filaments that cover the viral DNA. There are many members of this viral genus, including such species as variola (smallpox), cowpox, buffalopox, camelpox, rabbitpox, and others. Most species infect a particular animal species but occasionally may infect other mammals.

Figure 1: Monkeypox virus, brick-shaped negative stained virus grown in tissue cultures, visualized by electron microscopy; SOURCE: CDC/Cynthia S. Goldsmith, Inger K. Damon, and Sherif R. Zaki

Transmission of monkeypox is usually by direct contact with infected animals or possibly by eating poorly cooked meat from an infected rodent or monkey. Cutaneous or mucosal lesions on the infected animal -- especially when the human skin gets bites, scratches, or other trauma -- are a likely source for virus infection. Person-to-person transfer, probably by infected respiratory droplets, is possible but is not often documented. One study suggested that only about 8%-15% of infections were transmitted person to person among close family members.

Monkeypox is a relatively uncommon disease. Risk factors include animal bites and scratches from infected animals (mainly African rodents or monkeys) or from other rodents (like prairie dogs) that have had contact with African animals infected with the virus. Avoid eating any meat from such animals is advised. Recent studies have shown that several species of mammals can be infected with monkeypox, even though the species had never been associated with the virus in their normal environment. Person-to-person transfer, although infrequent, can be reduced or prevented by avoiding direct physical contact with the patient and having the patient's caregivers wear gloves and face masks.