The current monkeypox situation is constantly evolving and subject to change.


CDPH is closely monitoring monkeypox transmission in the U.S. and California to ensure rapid identification of cases. The risk of monkeypox to the public is currently very low based on the information available.


The U.S. Centers for Disease Control and Prevention (CDC) issued a health advisory on May 20, 2022 regarding a confirmed case of monkeypox virus infection in Massachusetts as well as multiple clusters of monkeypox virus infections in other countries that do not usually have monkeypox cases. Many of the cases have occurred among persons self-identifying as men who have sex with men (MSM).


Additionally, CDPH issued an updated advisory on May 27 and also issued an advisory on May 20 to health care providers to immediately notify their local health jurisdiction (LHJ) of any potential cases.


Visit the CDC’s webpage on Monkeypox in the United States for more information.


About Monkeypox

Monkeypox is a rare disease that is caused by infection with the monkeypox virus. Monkeypox virus belongs to the Orthopoxvirus genus which includes the variola (smallpox) virus as well as the vaccinia virus, which is used in the smallpox vaccine. Monkeypox is of public health concern because the illness is similar to smallpox and can be spread from infected humans, animals, and materials contaminated with the virus, but monkeypox is less transmissible than smallpox. Monkeypox was first identified in 1958 and occurs primarily in Central and West African countries. Monkeypox cases have occurred in the U.S. (mostly related to international travel or importation of animals) but they remain very rare here.



In humans, symptoms of monkeypox can be similar but milder than symptoms of smallpox.


Symptoms can begin with:


  • Fever
  • Headache
  • Muscle aches
  • Backache
  • Swollen lymph nodes
  • Chills
  • Exhaustion


Within 1 to 3 days (sometimes longer) after the appearance of fever, the patient can develop a rash that progresses from being red and flat, to being a bump, to being water filled, to being pus-filled, to being a crust, often beginning on the face and then spreading to other parts of the body (like the extremities and genital areas).


The time from infection to symptoms for monkeypox is usually 7−14 days, but can range from 5−21 days. The illness typically lasts for 2−4 weeks.


Anyone who has symptoms of monkeypox, such as characteristic rashes or lesions, should contact a health care provider right away.



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), the respiratory tract, or the mucous membranes (eyes, nose, or mouth). Current risk factors for contracting monkeypox include those who:


  1. Traveled (within 21 days) to an area where monkeypox cases or exposures have been reported;
  2. Reported contact with a person who has a similar rash or received a diagnosis of confirmed or suspected monkeypox; and
  3. Persons self-identifying as men who have sex with men (MSM).



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


  • 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.
  • 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 direct contact with any materials, such as bedding or laundry, that has been in contact with a sick animal or patient. (Monkeypox virus can be killed with standard washing machine with warm water and detergent.)
  • Use appropriate personal protective equipment (PPE) when caring for patients, which includes gown, gloves, respirator, and eye protection.


California Department of Public Health. (2022). Monkeypox. Retrieved from