updated October 1, 2022
Several poxviruses infect humans, ranging from the deadly smallpox to the contagious but not serious molluscum contagiosum. Now more than 30 countries, including the United States are experiencing an outbreak of monkeypox, which the World Health Organization is calling a”a public health emergency of international concern.”
What is monkeypox?
Monkeypox, an orthopoxvirus, was first isolated in the late 1950s from a colony of sick monkeys in Copenhagen Denmark. The virus is related to the variola, smallpox, and vaccinia, coxpox, viruses. The first known human case was found in the Democratic Republic of the Congo in 1970.
Where is monkeypox found?
Since routine smallpox immunization ended, most cases have occurred in Central and West Africa. Sporadic cases have been reported in several non-endemic countries, typically in returning travelers.
How does it spread?
The virus is typically acquired through contact with an infected animal’s bodily fluids or through a bite.
Human-to-human transmission can also occur through close contact with infectious skin lesions. Direct contact with lesions that contain the virus can easily transmit the disease .
Transmission can also occur through large respiratory droplets, and prolonged face-to-face contact (eg, within 6 feet for ≥3 hours in the absence of personal protection equipment [PPE]).
What are the symptoms of monkeypox?
Onset of monkeypox infection is 5 days to 3 weeks after exposure.
Predominant symptoms of monkeypox include
- enlarged lymph nodes,
- sore throat,
- muscle aches,
The rash is similar to that of smallpox or chickenpox. The illness usually lasts 2 to 4 weeks.
How do doctors diagnose monkeypox?
Doctors usually suspect monkeypox based on symptoms, especially a suspicious rash. Testing is done on specimens collected by swabbing monkeypox lesions, but should only be obtained by professionals wearing appropriate PPE.
CDC is working with state and local health officials to identify people who may have been in contact with individuals who have tested positive for monkeypox, so they can monitor their health.CDC website
This electron microscopic (EM) image depicted a monkeypox virion, obtained from a clinical sample associated with the 2003 prairie dog outbreak. It was a thin section image from of a human skin sample. On the left were mature, oval-shaped virus particles, and on the right were the crescents, and spherical particles of immature virions. credit CDC, Cynthia S. Goldsmith, Russell Regnery
What treatments are available?
Most patients have mild disease and recover with home supportive care, similar to influenza, COVID, and other viral infections. For the seriously ill patient, medically supervised supportive care is necessary until recovery.
The antiviral agents, tecovirimat and brincidofovir, approved for treatment of smallpox in the United States, work for monkeypox in animals and are likely to work in humans.
Can monkeypox be prevented?
When a rash is present, persons with suspected monkeypox should be considered infectious and be isolated until all scabs separate and results of testing are negative.
Detailed information on infection control precautions to reduce transmission of monkeypox in the home is on the CDC website.
Persons with close contact with an infected animal or person should be monitored for symptoms for 21 days after their last exposure .
Detailed information on the approach to monitoring after an exposure can be found on the CDC website.
Is there a vaccine?
The JYNNEOS vaccine is approved for prevention of smallpox and monkeypox. It is the primary vaccine being used during this outbreak in the U.S.
The ACAM2000 vaccine is an alternative to JYNNEOS. It is also approved to help protect against smallpox and monkeypox.
Is monkeypox fatal?
In Central Africa, the fatality rate is approximately 10 percent, generally in the second week of illness.
In the 2003 outbreak in the United States, none of the 34 confirmed cases died, although a few became seriously ill, requiring hospitalization.
Exploring the HEART of international health
cover image by Jerney Furman