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

The California Department of Public Health (CDPH) is closely monitoring MPX transmission in the U.S. and California to ensure rapid identification of cases. If you have sex or intimate physical contact with many people, risk of contracting MPX is higherFor additional information on MPX, visit the Los Angeles County Department of Public Health.

The U.S. Centers for Disease Control and Prevention (CDC) issued a health advisory on May 20, 2022 regarding a confirmed case of MPX virus infection in Massachusetts as well as multiple clusters of MPX virus infections in other countries that do not usually have MPX 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 and the CDPH Monkeypox Q&A page for more information.

MPX is a rare disease that is caused by infection with the MPX virus. MPX 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.  MPX 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 MPX is less transmissible than smallpox.  MPX was first identified in 1958 and occurs primarily in Central and West African countries. MPX 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 MPX 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 MPX 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 MPX, such as characteristic rashes or lesions, should contact a health care provider right away.

MPX is a viral infection that can spread through contact with body fluids, MPX sores, or shared items (such as clothing and bedding) that have been contaminated with fluids or sores of a person with MPX. Although MPX is not generally considered a sexually transmitted infection, it can be transmitted during sex through skin-to-skin and other intimate contact, regardless of gender or sexual orientation. Individuals with MPX may spread the virus through:

  • Respiratory secretions through prolonged face-to-face interactions (the type that mainly happen when living with someone or caring for someone who has MPX)
  • Direct skin-to-skin contact with rash lesions or infectious sores/scabs
  • Sexual/intimate contact, including kissing, hugging, massaging and cuddling
  • Living in a house and sharing a bed with someone
  • Sharing towels or unwashed clothing

MPX is NOT spread through casual brief conversations or walking by someone (like in a grocery store).

MPX is contagious and spreads easily to others until scabs have fallen off and a new layer of skin has formed. To prevent the spread of MPX, PPHD recommends:

  • Avoiding close physical contact with people who have symptoms, including sores or rashes
  • Talking to your sexual partner(s) about any recent illness and being aware of new or unexplained sores or rashes
  • Avoiding contact with contaminated materials
  • Wearing personal protective equipment (i.e., mask, gloves, gown) if you cannot avoid close contact with someone who has symptoms
  • Practicing good hand hygiene
  • Speaking to your healthcare provider about getting tested if you have symptoms
  • Staying in isolation until you are no longer considered infectious per public health guidance

There are number of measures that can be taken to prevent infection with MPX 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 MPX occurs).
  • Avoid direct contact with any materials, such as bedding or laundry, that has been in contact with a sick animal or patient. (MPX 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.
  • Speak to your healthcare provider about getting tested if you have symptoms.
  • See below for vaccine information.

Vaccine Eligibility

If you meet any of the below criteria, you can sign up for PPHD's MPX vaccination clinics on MyTurn.

MPX vaccine will be available to residents who self-attest to being in the following groups:

  • UPDATE: Any man or transgender person who has sex with men or transgender persons
  • UPDATE: Persons of any gender or sexual orientation who engage in commercial and/or transactional sex or have sex in association with a large public event
  • Persons living with HIV, especially persons with uncontrolled or advanced HIV disease
  • Persons who had skin-to-skin or intimate contact with someone with suspected or confirmed MPX, including those who have not yet been confirmed by Public Health.
  • Sexual partners of people in any of the above groups
  • People who anticipate being in any of the above groups

 Note: If residents met prior eligibility criteria, they are still vaccine-eligible (see below for prior criteria).

Gay or bisexual men or transgender people who:

  • Had multiple or anonymous sex partners in the past 14 days
  • Had skin-to-skin or intimate contact with persons at large venues or events in the past 14 days
  • Had a history of early syphilis or gonorrhea in the past 12 months
  • Are on HIV pre-exposure prophylaxis (PrEP)
  • Had anonymous sex or sex with multiple partners in the past 21 days in a commercial sex venue or other venue. 

MPX vaccine will continue to be available through direct outreach by DPH for select high-risk groups:

  • People who have had high- or intermediate-risk contact with someone with MPX (as defined by CDC and confirmed by Public Health).
  • People who attended an event or venue where there was high risk of exposure through skin-to-skin or intimate contact to individual(s) with MPX.
  • Persons experiencing homelessness (PEH) with high-risk behaviors.
  • People in high-risk cohorts identified by clinical staff in the LA County Jail system
  • Other community groups at high risk of exposure to MPX

MPX vaccine is also available for persons in select occupational groups whose jobs may expose them to orthopoxviruses including:

  • Research laboratory personnel working with orthopoxviruses
  • Clinical laboratory personnel performing diagnostic testing for orthopoxviruses
  • Designated public health response team members
  • Health care personnel who administer ACAM2000 (Smallpox [Vaccinia] Vaccine, Live)
  • Designated health care workers who care for persons with suspected or confirmed orthopoxvirus infections, including clinicians and environmental services personnel. Note, the risk of MPX transmission remains very low for health care workers if appropriate personal protective equipment is worn.

Public Health or clinic partners will directly communicate to eligible patients to provide details on how and where to access the JYNNEOS vaccine.


Individuals who suspect they may have MPX and wish to get tested can:

  1. Contact their healthcare provider
  2. Call 2-1-1 (if they don't have a provider or health insurance)
  3. Visit a Public Health Sexual Health Clinic

What is MPX?

MPX is a rare disease that is caused by infection with the MPX virus and is related to the smallpox virus. It can be spread from infected humans, animals, and materials contaminated with the virus. While generally less severe and much less infectious than smallpox, MPX can be a serious illness.

Is MPX a new disease?

No, MPX is not a new disease. MPX was first discovered in 1958 in monkeys, hence the name 'monkeypox.' The first human case of MPX was recorded in 1970 in the Democratic Republic of Congo. The MPX is endemic (regularly found) in west and central African countries.

Should I be worried about MPX?

While it's good to stay alert about any emerging public health outbreaks, the current risk of getting MPX is very low. MPX is a known illness that spreads through very close contact compared to other infectious diseases like COVID-19 that are primarily spread though very small particles in the air. MPX is also only typically contagious when symptoms like a rash are present, making it easier for infected individuals to isolate from others to prevent further spread.

Is MPX related to COVID-19?

No, MPX is a completely different disease and is not related to COVID-19. MPX is much less contagious than COVID-19 and spreads much slower. This is partly because people with MPX are only usually contagious to people whom they've had very close contact with when they have symptoms like a rash, compared with COVID-19 which can spread through the air and when people do not have symptoms.

Does the MPX virus have variants?

All viruses change and evolve over time, however, the MPX virus mutates slower than coronaviruses.  There are two known variants of MPX virus - the variant recently identified in Europe and in the U.S. is the West African strain and tends to cause less severe disease.

Who can get MPX?

Anyone can get MPX after having close physical contact with someone who has the infection, especially contact with infected lesions or other bodily fluids. However, the current risk to the public is low.

In 2022, many cases of MPX have been reported in several countries that don't normally report MPX, like in the United States, including California. Though not exclusively, these cases include gay, bisexual, and other men who have sex with men, and household contacts.

How is MPX transmitted?

MPX spreads primarily between people through direct contact with infectious sores, scabs, or body fluids, including during sex as well as activities like kissing and cuddling. It can be spread by respiratory secretions (talking, coughing, sneezing, breathing) during prolonged, face-to-face contact. At this time, it is not known if MPX can spread through semen or vaginal fluids. MPX can also spread through touching contaminated materials, such as clothing and bedding.

What are the signs and symptoms of MPX?

MPXcan start with symptoms like the flu, with fever, low energy, swollen lymph nodes, and general body aches. Within 1 to 3 days (sometimes longer) after the appearance of fever, the person can develop a rash that progresses from red and flat, to a bump, to water-filled, to pus-filled, to a crust, often beginning on the face and then spreading to other parts of the body (like the arms, legs, and genitals). It may also be limited to one part of the body.

When is MPX infectious?

Infection with MPX virus begins with an incubation period. A person is not contagious during this period. Usually, people are only infectious when they have symptoms, including rash.

The incubation period averages 7−14 days but can range from 5−21 days. During this period, a person does not have symptoms and may feel fine.

How serious is MPX?

Most cases are mild but MPX can be severe and can also lead to death.

Is MPX a sexually transmitted infection (STI)?

MPX can spread from skin-to-skin contact, or because of contact with a contaminated surface or material. This includes close or intimate physical contact with infected people, including sexual contact, and especially when touching rashes or contaminated objects or surfaces. Scientists are trying to better understand if virus could be present in semen or vaginal fluids, but this has not previously been noted as a route of transmission.

How is MPX prevented?

There are number of measures that can be taken to prevent infection with MPX virus, including:

  • isolation of infected persons until their symptoms, including rash, has gone away completely,
  • practicing good hand hygiene,
  • avoiding close contact with people with symptoms like sores or rashes,
  • avoiding contact with infected animals and materials contaminated with the virus,
  • and using appropriate personal protective equipment (PPE) (like a mask, gown and gloves) when caring for others with symptoms.

What should someone do if they are exposed to MPX or have symptoms?

Contact a health care provider as soon as possible and let them know you have symptoms or have been exposed to MPX. Health care providers and local health departments may recommend a vaccine for those who are exposed to help prevent infection or decrease the seriousness of the illness.  Health care providers can also provide care for people who test positive.

Is there a MPX vaccine?

  • Two vaccines licensed by the U.S. Food and Drug Administration (FDA) are available for preventing MPX infection – JYNNEOS (also known as Imvamune or Imvanex) and ACAM2000.
  • There is an ample supply of ACAM2000. However, this vaccine should not be used in people who have some health conditions, including a weakened immune system, skin conditions like atopic dermatitis/eczema, or pregnancy.
  • People are considered fully vaccinated about 2 weeks after their second shot of JYNNEOS and 4 weeks after receiving ACAM2000. However, people who get vaccinated should continue to take steps to protect themselves from infection by avoiding close, skin-to-skin contact, including intimate contact, with someone who has MPX.
  • To better understand the protective benefits of these vaccines in the current outbreak, CDC will collect data on any side effects and whether the way the person was infected makes any difference in how well the vaccine protects them.
  • When properly administered before or after a recent exposure, vaccines can be effective tools at protecting people against MPX illness.

Vaccine Strategies to Prevent MPX:

  • MPX Vaccine Post-Exposure Prophylaxis (PEP): For the current outbreak, this approach can be considered as “standard PEP” for MPX. People can be vaccinated following exposure to MPX to help prevent illness from MPX virus. It is important that states and other jurisdictions identify contacts of confirmed or probable MPX cases to offer vaccine for PEP and to monitor for any early signs of illness. CDC recommends that the vaccine be given within 4 days from the date of exposure for the best chance to prevent onset of the disease. If given between 4 and 14 days after the date of exposure, vaccination may reduce the symptoms of disease, but may not prevent the disease. However, when coupled with self-isolation and other prevention measures when symptoms first occur, PEP is important for controlling outbreaks and preventing further transmission of MPX.
  • Outbreak Response MPX Vaccine Post-Exposure Prophylaxis (PEP)++: For the current outbreak, this expanded approach can be considered as “individual-directed PEP” for MPX; public health officials refer to it as “expanded PEP” or “PEP plus-plus” or “PEP++”.  People with certain risk factors are more likely to have been recently exposed to MPX. The PEP++ approach aims to reach these people for post-exposure prophylaxis, even if they have not had documented exposure to someone with confirmed MPX. When coupled with self-isolation and other prevention measures when symptoms first occur, PEP++ may help slow the spread of the disease in areas with large numbers of MPX cases—which would suggest a higher level of MPX virus transmission.
  • MPX Vaccine Pre-Exposure Prophylaxis (PrEP): This approach refers to administering vaccine to someone at high risk for MPX (for example, laboratory workers who handle specimens that might contain MPX virus).  At this time, most clinicians in the United States and laboratorians not performing the orthopoxvirus generic test to diagnose orthopoxviruses, including MPX virus, are not advised to receive MPX vaccine PrEP.

Public Health or clinic partners will directly communicate to eligible patients to provide details on how and where to access the JYNNEOS vaccine.


City of Pasadena MPX Dashboard

The Pasadena Public Health Department (PPHD) will be updating the MPX public dashboard every Wednesday. If you have sex or intimate physical contact with many people, risk of contracting MPX is higher. PPHD will continue to conduct case investigation and contact tracing to all confirmed and probable cases.