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Monkeypox Information for Clinicians

Last Updated: Jul 29, 2022

General Information

What is monkeypox?

Monkeypox is a rare disease that is caused by infection with monkeypox virus. Monkeypox virus belongs to the Orthopoxvirus genus in the family Poxviridae. The Orthopoxvirus genus also includes variola virus (which causes smallpox), vaccinia virus (used in the smallpox vaccine), and cowpox virus.

What is the current status of monkeypox cases?

As of May 23, 2002 the CDC is investigating one confirmed and four presumptive cases of monkeypox in the US. CDC is also tracking multiple clusters of monkeypox that have been reported in early- to mid-May in several countries that don’t normally report monkeypox, including in Europe and North America. It’s not clear how people in those clusters were exposed to monkeypox but cases include people who self-identify as men who have sex with men.

CDC is urging healthcare providers in the U.S. to be alert for patients who have rash illnesses consistent with monkeypox, regardless of whether they have travel or specific risk factors for monkeypox and regardless of gender or sexual orientation.

What are the case definitions for monkeypox?

Person Under Investigation

Persons under investigation (PUI) are individuals who are reported as suspicious but have not been tested in an LRN laboratory. This includes cases that health departments have been consulted on because of clinician concern.

Possible Case

Meets one of the epidemiologic criteria AND has fever or new rash AND at least one other sign or symptom with onset 21 days after last exposure meeting epidemiologic criteria

Probable Case

Meets one of the epidemiologic criteria AND has new rash with or without fever AND at least one other sign or symptom with onset 21 days after last exposure meeting epidemiologic criteria AND
Demonstration of detectable levels of anti-orthopoxvirus IgM antibody during the period of 4 to 56 days after rash onset

Confirmed Orthopoxvirus Case

Meets possible case definition AND
Demonstration of orthopoxvirus DNA by polymerase chain reaction testing of a clinical specimen OR demonstration of presence of orthopoxvirus using immunohistochemical or electron microscopy testing methods

Confirmed Monkeypox Case

Meets possible case definition AND
Demonstration of presence of monkeypox virus DNA by polymerase chain reaction testing or Next-Generation sequencing of a clinical specimen OR isolation of monkeypox virus in culture from a clinical specimen

Clinical Criteria

New rash (any of the following)
- Macular
- Papular
- Vesicular
- Pustular
- Generalized or localized
- Discrete or confluent
Fever (either of the following)
- Subjective
- Measured temperature of ≥100.4° F [>38° C]
Other signs and symptoms:
- Chills and/or sweats
- New lymphadenopathy (periauricular, axillary, cervical, or inguinal)

Epidemiologic Criteria

Within 21 days of illness onset:

Report having had contact with a person or people who have a similar appearing rash or received a diagnosis of confirmed or probable monkeypox OR
Is a man who regularly has close or intimate in-person contact with other men, including through an online website, digital application (“app”), or social event (e.g., a bar or party) OR
Traveled to a country with confirmed cases of monkeypox AND at least one of the above criteria OR
Traveled to country where MPXV is endemic OR
Contact with a dead or live wild animal or exotic pet that is an African endemic species or used a product derived such animals (e.g., game meat, creams, lotions, powders, etc.)

Exclusion Criteria

A case may be excluded as a possible, probable, or confirmed monkeypox case if:

An alternative diagnosis* can fully explain the illness OR
An individual with symptoms consistent with monkeypox but who does not develop a rash within 5 days of illness onset OR
A case where specimens do not demonstrate the presence of orthopoxvirus or monkeypox virus or antibodies to orthopoxvirus as describe in the laboratory criteria

Prevention/Transmission

How can monkeypox be prevented?

There are number of measures that can be taken to prevent infection with monkeypox virus:

Avoid contact with animals that could harbor the virus (including animals that are sick or that have been found dead in areas where monkeypox occurs).
Avoid contact with any materials, such as bedding, that has been in contact with a sick animal.
- Isolate infected patients from others who could be at risk for infection.
  - Practice good hand hygiene after contact with infected animals or humans. For example, washing your hands with soap and water or using an alcohol-based hand sanitizer.
- Use PPE when caring for patients

How is monkeypox transmitted?

Transmission of monkeypox virus occurs when a person comes into contact with the virus from an animal, human, or materials contaminated with the virus. The virus enters the body through broken skin (even if not visible), respiratory tract, or the mucous membranes (eyes, nose, or mouth). Animal-to-human transmission may occur by bite or scratch, bush meat preparation, direct contact with body fluids or lesion material, or indirect contact with lesion material, such as through contaminated bedding. Human-to-human transmission is thought to occur primarily through large respiratory droplets. Respiratory droplets generally cannot travel more than a few feet, so prolonged face-to-face contact is required. Other human-to-human methods of transmission include direct contact with body fluids or lesion material, and indirect contact with lesion material, such as through contaminated clothing or linens.

Identification/Presentation

What are the signs and symptoms of monkeypox?

Monkeypox begins with:

Fever
Headache
Muscle aches
Backache
Swollen lymph nodes
Chills
Exhaustion
Within 1-3 days (possibly longer) after the appearance of fever, the patient develops a rash, often beginning on the face then spreading to other parts of the body.

What are the key characteristics for identifying monkeypox?

The key characteristics of monkeypox include:

Lesions are well circumscribed, deep seated, and often develop umbilication (resembles a dot on the top of the lesion)
Lesions are relatively the same size and same stage of development on a single site of the body (ex: pustules on face or vesicles on legs)
Fever before rash
Lymphadenopathy common
Disseminated rash is centrifugal (more lesions on extremities, face)
Lesions on palms, soles
Lesions are often described as painful until the healing phase when they become itchy (crusts)

What Are Phases of Monkeypox?

Incubation

After infection, the incubation period lasts on average 7-14 days but can range from 5-21 days. A person is not contagious during the incubation period.

Prodome

The development of the initial symptoms (fever, headache, malaise, etc.) marks the beginning of the prodromal period. A person may be contagious during this period.

Lymphadenopathy is a distinguishing feature of monkeypox from smallpox. This typically occurs with fever onset in the neck, armpits, or groin, and on both or just one side of the body.

Rash

Following the prodrome, lesions will develop in the mouth and on the body. They progress through several stages before falling off. A person is contagious from the onset of the enanthem through the scab stage.

Lesions progress through the following stages before falling off:

Macules
Papules
Vesicles
Pustules
Scabs

What is the duration of the lesion phases?

Enanthem Through the Scab Stage

Stage	Stage Duration	Characteristics
Enanthem		The first lesions to develop are on the tongue and in the mouth.
Macules	1−2 days	Following the enanthem, a macular rash appears on the skin, starting on the face and spreading to the arms and legs and then to the hands and feet, including the palms and soles. The rash typically spreads to all parts of the body within 24 hours becoming most concentrated on the face, arms, and legs (centrifugal distribution).
Papules	1−2 days	By the third day of rash, lesions have progressed from macular (flat) to papular (raised).
Vesicles	1−2 days	By the fourth to fifth day, lesions have become vesicular (raised and filled with clear fluid).
Pustules	5−7 days	By the sixth to seventh day, lesions have become pustular (filled with opaque fluid) – sharply raised, usually round, and firm to the touch (deep seated). Lesions will develop a depression in the center (umbilication). The pustules will remain for approximately 5 to 7 days before beginning to crust.
Scabs	7−14 days	By the end of the second week, pustules have crusted and scabbed over. Scabs will remain for about a week before beginning to fall off.

Pitted scars and/or areas of lighter or darker skin may remain after scabs have fallen off. Once all scabs have fallen off a person is no longer contagious.

Suspected Diagnosis

When should I consider a diagnosis of monkeypox in a patient?

Clinicians should consider a diagnosis of monkeypox in patients with an unexplained rash and:

Travel to a country where monkeypox cases have been reported
Reports contact with a person who has a similar rash or received a diagnosis of confirmed or suspected monkeypox, or
Is a man who had had close or intimate in-person contact with other men in the past month, including through an online website, digital app, or at a bar or party

What should I do if I suspect a patient may have monkeypox?

If you suspect monkeypox in a patient, you should contact the Pennsylvania Department of Health Division of Infectious Disease Epidemiology (717-787-3350) or your local health department immediately.

County Health Dept.	Phone Number	Municipal Health Dept.	Phone Number
Allegheny Co. Health Dept.	412-687-2243	Allentown Bureau of Health	610-437-7760
Bucks Co. Dept. of Health	215-345-3318	Bethlehem Health Bureau	610-865-7083
Chester Co. Health Dept.	610-344-6225	Wilkes-Barre City Health Dept.	570-208-4284
Delaware Co. Health Dept.	484-276-2100	York City Health Bureau	717- 849-2299
Erie Co. Dept. of Health	814-451-6700
Montgomery Co. Health Dept.	610-278-5117
Philadelphia Dept. of Public Health	215-686-5200

Treatment/Isolation

What treatment is available for monkeypox?

At this time, there are no specific treatments available for monkeypox infection.

Smallpox vaccine, cidofovir, ST-246, and vaccinia immune globulin (VIG) can be used to control a monkeypox outbreak. CDC guidance was developed using the best available information about the benefits and risks of smallpox vaccination and drug use for the prevention and management of monkeypox and other orthopoxvirus infections.

One vaccine, JYNNEOS^TM (also known as Imvamune or Imvanex), has been licensed in the United States to prevent monkeypox and smallpox. Because monkeypox virus is closely related to the virus that causes smallpox, smallpox vaccine can also protect people from getting monkeypox.

You can find out more information from the CDC about the use and effectiveness of treatment here.

Should patients with monkeypox be isolated?

Patients who do not require hospitalization for medical indications may be isolated at home using protective measures.

The ability to implement isolation and infection control measures in a home setting is likely to vary depending on the following factors:

If patient is a child or adult
The presence of additional infected or uninfected persons or pets in the home
The nature and extent of lesions in each case

The following principles should be considered and adopted to the extent possible in the home setting:

Persons with extensive lesions that cannot be easily covered (excluding facial lesions), draining/weeping lesions, or respiratory symptoms (e.g., cough, sore throat, runny nose) should be isolated in a room or area separate from other family members when possible.
Persons with monkeypox should not leave the home except as required for follow-up medical care. They also should avoid contact with wild or domestic mammals if possible.
Unexposed persons who do not have an essential need to be in the home should not visit.
Household members who are not ill should limit contact with the person with monkeypox.
Pets should be excluded from the ill person’s environment.

For individuals with monkeypox, isolation precautions, either in healthcare facilities or home settings, should be continued until all lesions have resolved and a fresh layer of skin has formed.

Following the discontinuation of isolation precautions, affected individuals should avoid close contact with immunocompromised persons until all crusts are gone.

Should PPE be used by people with monkeypox and other members of their household?

Persons with monkeypox should wear a surgical mask, especially those who have respiratory symptoms (e.g., cough, shortness of breath, sore throat). If this is not feasible (e.g., a child with monkeypox), other household members should consider wearing a surgical mask when in the presence of the person with monkeypox.

Disposable gloves should be worn for direct contact with lesions and disposed of after use.

Skin lesions should be covered to the best extent possible (e.g., long sleeves, long pants) to minimize risk of contact with others.

Contain and dispose of contaminated waste (such as dressings and bandages) after consultation with state or local health officials. Do not dispose of waste in landfills or dumps.

Risk Assessment/Monitoring Potential Exposures

How should I monitor a patient who has been exposed to monkeypox?

Contacts of animals or people confirmed to have monkeypox should be monitored for symptoms for 21 days after their last exposure.

Symptoms of concern include:

Fever ≥100.4°F (38°C)
Chills
New lymphadenopathy (periauricular, axillary, cervical, or inguinal)
New skin rash

Contacts should be instructed to monitor their temperature twice daily. If symptoms develop, contacts should immediately self-isolate and contact the health department for further guidance.

If fever or rash develop, contacts should self-isolate and contact their health care provider immediately.

If only chills or lymphadenopathy develop, the contact should remain at their residence and self-isolate for 24-hours.

During this time, the individual should monitor their temperature for fever; if a fever or rash develop, they should contact their health care provider immediately.
If fever or rash do not develop and chills or lymphadenopathy persist, the contact should be evaluated by a clinician for potential cause.
Clinicians should contact the Pennsylvania Department of Health Division of Infectious Disease Epidemiology at 717-787-3350 or their local health department immediately if monkeypox is suspected.

Contacts who remain asymptomatic can be permitted to continue routine daily activities (e.g., go to work, school). Contacts should not donate blood, cells, tissue, breast milk, semen, or organs while they are under symptom surveillance.

What should a health care professionals do if exposed to monkeypox?

Any health care worker who has cared for a monkeypox patient should be alert to the development of symptoms that could suggest monkeypox infection, especially within the 21-day period after the last date of care and should follow their organization’s infection control procedures regarding medical evaluation.

Health care workers who have unprotected exposures (i.e., not wearing PPE) to patients with monkeypox do not need to be excluded from work duty, but should undergo active surveillance for symptoms, which includes measurement of temperature at least twice daily for 21 days following the exposure. Prior to reporting for work each day, the health care worker should be interviewed regarding evidence of fever or rash.

Health care workers who have cared for or otherwise been in direct or indirect contact with monkeypox patients while adhering to recommended infection control precautions may undergo self-monitoring or active monitoring as determined by the Pennsylvania Department of Health or the CDC.

Is there a risk assessment and public health recommendations for individuals exposed to a patient with monkeypox?

Transmission of monkeypox requires prolonged close interaction with a symptomatic individual. Brief interactions and those conducted using appropriate PPE in accordance with Standard Precautions are not high risk and generally do not warrant postexposure prophylaxis (PEP).

Degree of Exposure: High
Recommendations Monitoring - including ascertainment of selected signs and symptoms of monkeypox: fever (≥100.4°F [≥38°C]), chills, new lymphadenopathy (periauricular, axillary, cervical, inguinal), and new skin rash through 21 days after the exposure to the patient PEP– Recommended (ACAM2000 and Jynneos are available for PEP)
Exposure Characteristics Unprotected contact between a person’s skin or mucous membranes and the skin, lesions, or bodily fluids from a patient (e.g., any sexual contact, inadvertent splashes of patient saliva to the eyes or oral cavity of a person, ungloved contact with patient), or contaminated materials (e.g., linens, clothing) -OR- Being inside the patient’s room or within 6 feet of a patient during any procedures that may create aerosols from oral secretions, skin lesions, or resuspension of dried exudates (e.g., shaking of soiled linens), without wearing an N95 or equivalent respirator (or higher) and eye protection -OR- Exposure that, at the discretion of public health authorities, was recategorized to this risk level (i.e., exposure that ordinarily would be considered a lower risk exposure, raised to this risk level because of unique circumstances)

Degree of Exposure: High

Recommendations

Monitoring - including ascertainment of selected signs and symptoms of monkeypox: fever (≥100.4°F [≥38°C]), chills, new lymphadenopathy (periauricular, axillary, cervical, inguinal), and new skin rash through 21 days after the exposure to the patient

PEP– Recommended (ACAM2000 and Jynneos are available for PEP)

Exposure Characteristics

Unprotected contact between a person’s skin or mucous membranes and the skin, lesions, or bodily fluids from a patient (e.g., any sexual contact, inadvertent splashes of patient saliva to the eyes or oral cavity of a person, ungloved contact with patient), or contaminated materials (e.g., linens, clothing) -OR-

Being inside the patient’s room or within 6 feet of a patient during any procedures that may create aerosols from oral secretions, skin lesions, or resuspension of dried exudates (e.g., shaking of soiled linens), without wearing an N95 or equivalent respirator (or higher) and eye protection -OR-

Exposure that, at the discretion of public health authorities, was recategorized to this risk level (i.e., exposure that ordinarily would be considered a lower risk exposure, raised to this risk level because of unique circumstances)

Degree of Exposure: Intermediate
Recommendations · Monitoring - including ascertainment of selected signs and symptoms of monkeypox: fever (≥100.4°F [≥38°C]), chills, new lymphadenopathy (periauricular, axillary, cervical, inguinal), and new skin rash through 21 days after the exposure to the patient PEP– Informed clinical decision making recommended on an individual basis to determine whether benefits of PEP outweigh risks. PEP can be considered for contact through activities such as assistance with bathing, dressing, transferring, or other activities. (ACAM2000 and Jynneos are available for PEP)
Exposure Characteristics Being within 6 feet for 3 hours or more of an unmasked patient without wearing, at a minimum, a surgical mask -OR- Activities resulting in contact between sleeves and other parts of an individual’s clothing and the patient’s skin lesions or bodily fluids, or their soiled linens or dressings (e.g., turning, bathing, or assisting with transfer) while wearing gloves but not wearing a gown -OR- Exposure that, at the discretion of public health authorities, was recategorized to this risk level because of unique circumstances (e.g., if the potential for an aerosol exposure is uncertain, public health authorities may choose to decrease risk level from high to intermediate)

Degree of Exposure: Intermediate

Recommendations
· Monitoring - including ascertainment of selected signs and symptoms of monkeypox: fever (≥100.4°F [≥38°C]), chills, new lymphadenopathy (periauricular, axillary, cervical, inguinal), and new skin rash through 21 days after the exposure to the patient

PEP– Informed clinical decision making recommended on an individual basis to determine whether benefits of PEP outweigh risks. PEP can be considered for contact through activities such as assistance with bathing, dressing, transferring, or other activities. (ACAM2000 and Jynneos are available for PEP)

Exposure Characteristics

Being within 6 feet for 3 hours or more of an unmasked patient without wearing, at a minimum, a surgical mask -OR-

Activities resulting in contact between sleeves and other parts of an individual’s clothing and the patient’s skin lesions or bodily fluids, or their soiled linens or dressings (e.g., turning, bathing, or assisting with transfer) while wearing gloves but not wearing a gown -OR-

Exposure that, at the discretion of public health authorities, was recategorized to this risk level because of unique circumstances (e.g., if the potential for an aerosol exposure is uncertain, public health authorities may choose to decrease risk level from high to intermediate)

Degree of Exposure: Low/Uncertain
Recommendations Monitoring - None PEP– None
Exposure Characteristics Entered the patient room without wearing eye protection on one or more occasions, regardless of duration of exposure -OR- During all entries in the patient care area or room (except for during any procedures listed above in the high-risk category), wore gown, gloves, eye protection, and at minimum, a surgical mask -OR- Being within 6 feet of an unmasked patient for less than 3 hours without wearing at minimum, a surgical mask -OR- Exposure that, at the discretion of public health authorities, was recategorized to this risk level based on unique circumstances (e.g., uncertainty about whether Monkeypox virus was present on a surface and/or whether a person touched that surface)

Degree of Exposure: Low/Uncertain

Recommendations

Monitoring - None

PEP– None

Exposure Characteristics

Entered the patient room without wearing eye protection on one or more occasions, regardless of duration of exposure -OR-

During all entries in the patient care area or room (except for during any procedures listed above in the high-risk category), wore gown, gloves, eye protection, and at minimum, a surgical mask -OR-

Being within 6 feet of an unmasked patient for less than 3 hours without wearing at minimum, a surgical mask -OR-

Exposure that, at the discretion of public health authorities, was recategorized to this risk level based on unique circumstances (e.g., uncertainty about whether Monkeypox virus was present on a surface and/or whether a person touched that surface)

Degree of Exposure: No Risk
Recommendations Monitoring – None PEP– None
Exposure Characteristics Exposure that public health authorities deemed did not meet criteria for other risk categories

Degree of Exposure: No Risk

Recommendations

Monitoring – None

PEP– None

Exposure Characteristics

Exposure that public health authorities deemed did not meet criteria for other risk categories