County of Marin Health and Human Services

Mpox (formerly monkeypox)


On December 11, 2023 California Department of Public Health (CDPH) issued an advisory to notify clinicians about the occurrence, geographic spread, and sexually associated human-to-human transmission of Clade I Monkeypox virus (MPXV) in the Democratic Republic of the Congo (DRC). Clade I MPXV infections have historically been more transmissible and more severe compared to Clade IIb, which is currently circulating in the United States. Cases of Clade I MPXV have not been reported in the United States at this time. However, clinicians should be aware of the possibility of Clade I MPXV in travelers or close contacts (including sexual contacts) of travelers who have been in DRC.  

Clinicians should notify Marin County Public Health (MCPH) if they have a patient with mpox-like symptoms, which may include rash, sores, fever, and/or lymphadenopathy, in a traveler to or close contacts (including sexual contacts) of travelers returning from the DRC. MCPH will coordinate MPXV testing with CDPH.

On this page:

What is Monkeypox (Mpox)?

Mpox is a rare but potentially serious viral illness that typically begins with flu-like illness and swelling of the lymph nodes and progresses to a rash on the face and body. Most infections last 2-to-4 weeks. The virus does not spread easily between people; transmission can occur through contact with body fluids, sores, items that have been contaminated with fluids or sores (clothing, bedding, etc.), or through respiratory droplets following prolonged face-to-face contact.

Visual Examples of Monkeypox Rash

Cases of Mpox in Other Parts of the Country

Local Data

Data Source: California Immunization Registry (CAIR), California Reportable Disease Information Exchange (CalREDIE).

Note: A vaccine recipient is considered fully vaccinated for mpox if they meet at least one of the following criteria: 1) They received one dose of ACAM2000 (CVX 75) or 2) They received two JYNNEOS (CVX 206) doses at least 24 days apart.


Data Source: Verily WastewaterSCAN

Signs and Symptoms

Mpox typically begin with flu-like illness.  Symptoms of mpox can include:

  • Fever
  • Headache
  • Muscle aches and backache
  • Swollen lymph nodes
  • Chills
  • Exhaustion
  • A rash that can look like pimples or blisters that appears on the face, inside the month, or on other parts of the body, like hands, feet, chest, genitals, or anus.

The rash goes through different stages before healing completely. The illness typically lasts 2-4 weeks. Sometimes, people get a rash first, followed by other symptoms. Others only experience a rash.

How it Spreads

The mpox virus is spreading mostly through close, intimate contact with someone who has mpox.  Mpox can spread from the time symptoms start until the rash has fully healed with a fresh layer of skin has formed (this can take several weeks).

Mpox can be spread through:

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

Mpox is NOT spread through: 

  • Casual brief conversations 
  • Walking by someone with mpox, like in a grocery store  

How is it Prevented?

People at highest risk are those who have had close physical contact with someone actively infected with mpox. Based on statewide data, men are at highest risk for mpox infection. However, mpox can be acquired by anyone, regardless of gender identity or sexual orientation. Vaccination is an important tool in preventing the spread of mpox. 

How to protect yourself: 

  • Avoid close, skin-to-skin contact with people who have a rash that looks like mpox
    • Do not touch the rash or scabs.
    • Do not kiss, hug, cuddle or have sex with someone with mpox
  • Follow guidelines for safer sex
    • Condoms protect from sexually transmitted infections (STIs) but not mpox
  • Learn how to lower your risk at CDC's Safer Sex, Social Gatherings, and Monkeypox website 
    • Exchange contact information with any new partner to allow for sexual health follow-up
    • Take a temporary break from activities that increase exposure to mpox until you are two weeks after your second dose of MPX PrEP
    • Limit your number of sex partners to reduce your likelihood of exposure
    • Decrease participation in high-risk events (e.g., bath houses, saunas, sex clubs/parties)
    • Engage in sexual activity only with known partners

If you or your partner has or recently had mpox symptoms, or you have a new or unexplained rash anywhere on your body, do not have sex and see a healthcare provider.


JYNNEOS is a vaccine that can help prevent mpox infection. JYNNEOS is approved for adults 18 & over. It is a two dose injection series at least four weeks apart.  CDC advises that people exposed to mpox be given the vaccine to prevent them from developing the disease.

Anyone who wants protection from mpox infection may receive mpox vaccine.

Some people are still at higher risk of getting mpox than others, and those persons are now considered priority groups that are recommended to get the JYNNEOS vaccine.

Vaccine recommended for:

  • Persons who have had a known exposure to mpox and need post-exposure prophylaxis (PEP)
  • People with occupational (job-related) risk, including
    • Healthcare workers likely to collect laboratory specimens from patients with MPX
    • Persons working in sexual health clinics
    • Persons working in clinical settings that serve at-risk populations
    • Any occupational group recommended by Advisory Committee on Immunization Practices (ACIP) to get the vaccine
  • Any person living with HIV, especially those with risk of complications of mpox, such as persons with a CD4 count <350/mm3, an unsuppressed viral load, or who have had an opportunistic infection
  • Any man, trans person, or nonbinary person who has sex with men, trans persons, or nonbinary persons
  • Persons who are taking or are eligible to take HIV PrEP
  • Sex workers
  • Sexual contacts of any persons included above
  • Persons who have had close contact, within the past 6 months, with someone with suspected or confirmed MPX
  • Persons who had sex or close contact, within the past 6 months, at a venue or event, or within a social group, with a suspected or confirmed mpox case. This includes persons who received notice from a venue or event of a potential exposure.
  • Persons diagnosed, in the past 3 months, with a bacterial sexually transmitted disease (for example: Chlamydia, gonorrhea, syphilis)
  • Persons who expect to experience any of the above
  • Individuals are eligible for their 2nd doses 28 days after their 1st dose

Providers Offering Vaccines

Please contact clinics and health care providers directly to verify information, availability, and to make an appointment.  Don't forget to bring your immunization record with you each visit.

Upcoming Vaccine Clinics

No clinics currently scheduled.

What to do if you have been exposed

If you have been exposed and/or are symptomatic, contact your primary care provider for potential testing and treatment.  Anyone with a rash that looks like mpox should talk to their healthcare provider about whether they need to get tested, even if they don’t think they had contact with someone who has mpox.

If you are a Kaiser Permanente (KP) member and have been exposed and/or are symptomatic, contact KP at (415) 444-3100 (8:30 am to 5:00 pm Monday through Friday) or send a secure message through for more information. Do not go to the emergency room for testing.

Avoid crowds, close contact, including sexual or intimate contact until seeing your healthcare provider.

Provider Information

MCPH is urging healthcare providers to be alert for patients who have rash illnesses consistent with monkeypox.

Updated Clinical Assist Tool [PDF] (CDPH; June 14, 2023)

Case Finding & Management guidance

Clinical Presentation

Marin healthcare providers should be alert for patients who have rash illnesses consistent with mpox, regardless of whether they have travel or specific risk factors for mpox and regardless of gender or sexual orientation.

Suspected cases may present with early flu-like symptoms and progress to lesions that may begin on one site on the body and spread to other parts. Illness could be clinically confused with a sexually transmitted infection like syphilis or herpes, or with varicella zoster virus. Thus far in the U.S. outbreak, all patients diagnosed with MPX in the United States have experienced a rash or exanthem. Although the characteristic firm, deep-seated, well-circumscribed and sometimes umbilicated rash has been observed, the rash has often begun in mucosal areas (e.g., genital, perianal, oral mucosa) and in some patients, the lesions have been scattered or localized to a specific body site rather than diffuse and have not involved the face or extremities.

People with mpox in the current outbreak report having close, sustained physical contact with other people who have mpox. While nearly all affected are gay, bisexual, or other men who have sex with men, anyone who has been in close contact with someone who has mpox can get the illness.

See CDC’s Clinical Recognition webpage for more characteristics and photos of mpox rashes.


Commercial labs such as QuestLabCorp and other private labs are now testing for mpox Virus. There is no need to contact Marin County Public Health for approval to test at commercial laboratories but providers must still report all suspect cases to MCPH within 1 working day. To report suspected cases, please complete a Confidential Morbidity Report (CMR) [PDF] and fax to (415) 473-6002.


On July 21, 2022, Centers for Disease Control and Prevention (CDC) Institutional Review Board (IRB) approved an amendment and continuation of its research protocol to increase access to mpox treatment by providing umbrella regulatory coverage for clinicians and facilities and liability coverage for compensation to patients if injured.

Marin County Public Health encourages health care providers to obtain and use TPOXX (Tecovirimat) for the treatment of mpox when clinically indicated and with informed consent. Provider should review the TPOXX Provider Packet and determine readiness to obtain and use TPOXX for the treatment of active mpox.  

If a healthcare provider has a non-pediatric patient in urgent need of treatment, the provider may proceed with TPOXX treatment once informed consent has been obtained. To secure TPOXX for an immediate need, please contact the Marin County Public Health.  During business hours (Mon - Fri, 9 am - 5 pm), call (415) 473-4163.  After hours, call the On Call Health Officer (415) 499-7237.

Travel Advisories

  • Do not travel if you have mpox. Isolate at home or in another location until your symptoms are gone and your rash has healed; this means all scabs have fallen off and a fresh layer of skin has formed.
  • If you have mpox and must travel:
    • Make sure that you do not have fever or respiratory symptoms such as sore throat, nasal congestion, or cough.
    • Cover your rash and wear a well-fitting mask.
    • Take additional steps to prevent spread to others.
  • If you test positive for mpox while at your international destination, you may be subject to local public health laws and regulations. These could include requirements to isolate and not being allowed travel until you are no longer considered contagious.

Report a suspected case

To report suspected cases, please complete a Confidential Morbidity Report (CMR) [PDF] and fax to (415) 473-6002.


Page last reviewed: November 21, 2023