Animal-to-human transmission results in outbreak
For the most recent information on Monkeypox and this outbreak, please visit the CDC website.
On June 7, 2003, the Centers for Disease Control and Prevention reported cases of suspected monkeypox among residents of Wisconsin (17), northern Illinois (1), and northwestern Indiana (1). Onset of illness among patients began in early May. Patients typically experienced a prodrome consisting of fever, headaches, myalgias, chills, and drenching sweats. Roughly one-third of patients had nonproductive cough. This prodromal phase was followed 1-10 days later by the development of a papular rash that typically progressed through stages of vesiculation, pustulation, umbilication, and crusting. In some patients, early lesions have become ulcerated. Rash distribution and lesions have occurred on head, trunk, and extremities; many of the patients had initial and satellite lesions on palms and soles and extremities. Rashes were generalized in some patients. After onset of the rash, patients have generally manifested rash lesions in different stages. All patients reported direct or close contact with prairie dogs, most of which were sick. Illness in prairie dogs was frequently reported as beginning with a blepharoconjunctivitis, progressing to presence of nodular lesions in some cases. Some prairie dogs have died from the illness, while others reportedly recovered. This represents the first outbreak of monkeypox infection in the Western Hemisphere.
In May, the prairie dogs were sold by a Milwaukee animal distributor to two pet shops in the Milwaukee area and during a pet "swap meet" (pets for sale or exchange) in northern Wisconsin. The Milwaukee animal distributor had obtained prairie dogs and a Gambian giant rat that was ill at the time from a northern Illinois animal distributor. It is unclear whether other retail outlets are involved. Investigations are under way to traceback the source of the prairie dogs and the Gambian giant rat and determine if distributors in other states might be involved. Animal species susceptible to monkeypox virus may include non-human primates, lagomorphs (rabbits), and some rodents.
Human monkeypox is a rare zoonotic viral disease that occurs primarily in the rain forest of central and west Africa. Person-to person spread may occur but has not yet been shown for this outbreak. The incubation period averages 12 days. Case mortality in Africa runs from 1% to 10%, but may be lower in the United States, which has a healthier population base, and generally more advanced medical care.
The CDC currently recommends the measures below should be followed.
- Avoid contact with any prairie dogs or Gambian giant rats that appear to be ill (e.g., are missing patches of fur, have a visible rash on the skin, or have a discharge from eyes or nose).
- Wash hands thoroughly after any contact with prairie dogs, Gambian giant rats, or any ill animal.
- Physicians should consider monkeypox in persons with fever, cough, headache, myalgias, rash, or lymph node enlargement within three weeks after contact with prairie dogs or Gambian giant rats. Inform the treating physician or other clinician of the animal exposure.
- Veterinarians examining sick exotic animal species, especially prairie dogs and Gambian giant rats, should consider monkeypox. Veterinarians should also be alert to the development of illness in other animal species that may have been housed with ill prairie dogs or Gambian giant rats.
If a patient with suspect monkeypox infection is seen as an outpatient or admitted to the hospital, infection control personnel should be notified immediately. A combination of Standard, Contact, and Airborne Precautions should be applied in all health-care settings. These include:
- Hand hygiene after all contact with an infected patient and/or the environment of care.
- Use of gown and gloves for any contact with the patient and/or the environment of care.
- Eye protection (e.g. goggles or face shield) if splash or spray of body fluids is likely.
- Respiratory protection including a NIOSH-certified N95 filtering disposable respirator for entering the room or patient care area. If N95 respirators are not available for health-care personnel, then surgical masks should be worn.
- Airborne isolation room with negative pressure relative to the surrounding area. If a negative pressure room is not available, place the patient in a private room.
- Contain and dispose of contaminated waste (e.g., dressings) in accordance with facility-specific guidelines for infectious waste or local regulations pertaining to household waste.
- Use care when handling soiled laundry (e.g., bedding, towels, personal clothing) to avoid contact with lesion exudates. Soiled laundry should not be shaken or otherwise handled in a manner that may aerosolize infectious particles.
- Handle used patient-care equipment in a manner that prevents contamination of skin and clothing. Ensure that used equipment has been cleaned and reprocessed appropriately.
- Ensure that procedures are in place for cleaning and disinfecting environmental surfaces in the patient care environment. Any EPA-registered hospital detergent-disinfectant currently used by health-care facilities for environmental sanitation may be used. Manufacturer’s recommendations for use-dilution (i.e., concentration), contact time and care in handling should be followed.
For more detailed infection control procedures, please visit the CDC website.
No specific treatment recommendations are being made at this time. Smallpox vaccine has been reported to reduce the risk of monkeypox among previously vaccinated persons in Africa. CDC is assessing the potential role of postexposure use of smallpox vaccine as well as therapeutic use of the antiviral drug cidofovir.
Health care providers, veterinarians, and public health personnel should report cases of these illnesses in humans and animals to their state or local health departments as soon as they are suspected.
Submission of Specimens from Patients with Suspected Monkeypox
Procedures recommended for collection of samples for diagnosis of potential monkeypox disease are essentially the same as those for diagnosis of the related orthopoxvirus diseases, vaccinia and smallpox. Consultation with the state epidemiologist and state health laboratory is necessary for submission instructions before sending specimens to CDC.