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.
Monkeypox was first discovered in 1958 when two outbreaks of a pox-like disease occurred in colonies of monkeys kept for research, hence the name ‘monkeypox.’ The first human case of monkeypox was recorded in 1970 in the Democratic Republic of the Congo (DRC) during a period of intensified effort to eliminate smallpox. Since then, monkeypox has been reported in people in several other central and western African countries. Monkeypox cases in people have occurred outside of Africa linked to international travel or imported animals, including cases in the United States, as well as Israel, Singapore, and the United Kingdom.
The current monkeypox situation is rapidly evolving and the information below will be updated as new information emerges. The California Department of Public Health (CDPH) is closely monitoring monkeypox transmission in the U.S. and California to ensure rapid identification of cases.
In humans, the symptoms of monkeypox are similar to but milder than the symptoms of smallpox. Monkeypox begins with fever, headache, muscle aches, and exhaustion. The main difference between symptoms of smallpox and monkeypox is that monkeypox causes lymph nodes to swell (lymphadenopathy) while smallpox does not. The incubation period (time from infection to symptoms) for monkeypox is usually 7−14 days but can range from 5−21 days.
The illness begins with:
- Muscle aches
- Swollen lymph nodes
Within 1 to 3 days (sometimes longer) after the appearance of fever, the patient develops a rash, often beginning on the face then spreading to other parts of the body.
Lesions progress through the following stages before falling off:
The illness typically lasts for 2−4 weeks. In Africa, monkeypox has been shown to cause death in as many as 1 in 10 persons who contract the disease.
Monkeypox virus can spread when a person comes into contact with the virus from an infected animal, infected person, or materials contaminated with the virus. The virus can also cross the placenta from the mother to her fetus. Monkeypox virus may spread from animals to people through the bite or scratch of an infected animal, by handling wild game, or through the use of products made from infected animals. The virus may also spread through direct contact with body fluids or sores on an infected person or with materials that have touched body fluids or sores, such as clothing or linens.
Monkeypox spreads between people primarily through direct contact with infectious sores, scabs, or body fluids. It also can be spread by respiratory secretions during prolonged, face-to-face contact. Monkeypox can spread during intimate contact between people, including during sex, as well as activities like kissing, cuddling, or touching parts of the body with monkeypox sores. At this time, it is not known if monkeypox can spread through semen or vaginal fluids.
It is not yet known what animal maintains the virus in nature, although African rodents are suspected to play a part in monkeypox transmission to people.
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 personal protective equipment (PPE) when caring for patients.
Many individuals infected with monkeypox virus have a mild, self-limiting disease course in the absence of specific therapy. However, the prognosis for monkeypox depends on multiple factors such as previous vaccination status, initial health status, concurrent illnesses, and comorbidities among others. People who should be considered for treatment following consultation with CDC might include:
- People with severe disease (e.g., hemorrhagic disease, confluent lesions, sepsis, encephalitis, or other conditions requiring hospitalization)
- People who may be at high risk of severe disease:
- People with immunocompromise (e.g., human immunodeficiency virus/acquired immune deficiency syndrome infection, leukemia, lymphoma, generalized malignancy, solid organ transplantation, therapy with alkylating agents, antimetabolites, radiation, tumor necrosis factor inhibitors, high-dose corticosteroids, being a recipient with hematopoietic stem cell transplant <24 months post-transplant or ≥24 months but with graft-versus-host disease or disease relapse, or having autoimmune disease with immunodeficiency as a clinical component)1
- Pediatric populations, particularly patients younger than 8 years of age2
- Pregnant or breastfeeding women3
- People with a history or presence of atopic dermatitis, people with other active exfoliative skin conditions (e.g., eczema, burns, impetigo, varicella zoster virus infection, herpes simplex virus infection, severe acne, severe diaper dermatitis with extensive areas of denuded skin, psoriasis, or Darier disease [keratosis follicularis])
- People with one or more complications (e.g., secondary bacterial skin infection; gastroenteritis with severe nausea/vomiting, diarrhea, or dehydration; bronchopneumonia; concurrent disease or other comorbidities)4
- People with monkeypox virus aberrant infections that include its accidental implantation in eyes, mouth, or other anatomical areas where monkeypox virus infection might constitute a special hazard (e.g., the genitals or anus)
Medical Countermeasures Available for the Treatment of Monkeypox
Currently there is no specific treatment approved for monkeypox virus infections. However, antivirals developed for use in patients with smallpox may prove beneficial.
Monkeypox is a rare disease caused by the monkeypox virus
- Monkeypox can make you sick including a rash or sores (pox), often with an earlier flu-like illness
- Monkeypox can spread to anyone through close, personal, often skin-to-skin contact including:
- Direct contact with monkeypox rash, sores, or scabs
- Contact with objects, fabrics (clothing, bedding, or towels), and surfaces that have been used by someone with monkeypox
- Through respiratory droplets or oral fluids from a person with monkeypox
This contact can happen during intimate sexual contact including:
- Oral, anal, and vaginal sex or touching the genitals or anus of a person with monkeypox
- Hugging, massage, kissing, or talking closely
- Touching fabrics and objects during sex that were used by a person with monkeypox, such as bedding, towels and sex toys
We know the virus can be spread in fluid or pus from monkeypox sores, and are trying to better understand if virus could be present in semen, vaginal fluids or other body fluids
Monkeypox is a disease that can make you sick, including a rash, which may look like pimples or blisters, often with an earlier flu-like illness. Monkeypox can spread to anyone through close, personal, often skin-to-skin contact including:
- Direct contact with monkeypox rash, sores, or scabs from a person with monkeypox. We believe this is currently the most common way that monkeypox is spreading in the U.S.
- Contact with objects, fabrics (clothing, bedding, or towels), and surfaces that have been used by someone with monkeypox.
- Contact with respiratory secretions, through kissing and other face-to-face contact.
This contact can happen when you have sex including:
- Oral, anal, and vaginal sex or touching the genitals (penis, testicles, labia, and vagina) or anus (butt) of a person with monkeypox.
- Hugging, massage, and kissing
- Touching fabrics and objects during sex that were used by a person with monkeypox and that have not been disinfected, such as bedding, towels, fetish gear, and sex toys.
- Enclosed spaces, such as back rooms, saunas, or sex clubs, where there is minimal or no clothing and where intimate sexual contact occurs have a higher likelihood of spreading monkeypox.
Talk to your partner about any recent illness and be aware of new or unexplained sores or rashes on your body or your partner’s body, including the genitals and anus. If you or your partner have recently been sick, currently feel sick, or have a new or an unexplained rash or sores, do not have sex and see a healthcare provider. This is always a good plan, even if monkeypox isn’t in your area.
If you or a partner has monkeypox, the best way to protect yourself and others is to not have sex of any kind (oral, anal, vaginal) and not kiss or touch each other’s bodies while you are sick, especially any rash or sores. Do not share things like towels, fetish gear, sex toys, and toothbrushes.
If you or your partner have (or think you might have) monkeypox and you decide to have sex, consider the following to reduce the chance of spreading the virus:
- Have virtual sex with no in-person contact.
- Masturbate together at a distance of at least 6 feet, without touching each other and without touching any rash or sores.
- Consider having sex with your clothes on or covering areas where rash or sores are present, reducing as much skin-to-skin contact as possible.
- Avoid kissing.
- Remember to wash your hands, fetish gear, sex toys and any fabrics (bedding, towels, clothing) after having sex
- Limit your number of partners to avoid opportunities for monkeypox to spread.