CDPH - Community Spread of New Mpox Type (Clade I) in California Has Been Identified; Risk to General Public Remains Low

October 17, 2025

NR25-015

Three C lade I M pox C ases I dentified in Californians without a History of Recent I nternational T ravel​

​What You Need to Know: CDPH and local health departments have identified three unrelated cases of clade I mpox among Southern California residents without a history of recent international travel, indicating that person-to-person community spread is occurring in California. Mpox is spread through intimate contact and the risk to the general public remains low. Protect yourself by getting both doses of the mpox vaccine if you or your sex partner(s) may be at risk for mpox.

Sacramento- The California Department of Public Health (CDPH) and local health officials in the City of Long Beach and Los Angeles County, have identified three unrelated cases of clade I mpox in Californians who did not report recent travel outside the United States. These cases indicate that person-to-person community spread of clade I mpox is occurring in California, primarily impacting communities of gay and bisexual men, and other men who have sex with men, as well as their social networks. Prior cases of clade I mpox in the United States have been associated with international travel to areas where clade I mpox is circulating.

​All three cases required hospitalization and are now recovering. Local health departments and CDPH are conducting enhanced surveillance and contact tracing to identify any additional cases and prevent further transmission. At this time, the risk to the general public remains low.

"As we continue to monitor the situation, it is crucial for Californians to stay informed and take preventive measures, especially persons who are more likely to be exposed to mpox," said Dr. RitaNguyen, Assistant State Public Health Officer. "Clade I mpox cases can be severe. Risk of severe disease and hospitalization are highest for people with weakened immune systems, so it's critical to protect yourself by getting both doses of the mpox vaccine if you or your sex partner(s) may be at risk for mpox."

CDPH will continue to coordinate with local health departments and with the CDC as they are available during the federal government shutdown.

About M​​​pox

Mpox is an infection caused by the monkeypox virus. There are two types of mpox, clade I and clade II. Both types cause similar symptoms and can be prevented using the same methods and vaccine. Mpox mainly spreads through close contact to a person who has mpox infection. This includes:

• Intimate physical contact such as massages, cuddling, or sex (oral, anal, or vaginal)

• Direct skin-to-skin contact with the rash, scabs, or body fluids that touched sores

• Sharing a living space or personal items with someone who has mpox
  

• Spread from a pregnant person with mpox to the fetus or baby
  

Casual contact, like one might have in an airplane, office, or store, is unlikely to spread mpox.

Clade I mpox is different from clade II mpox, which has been circulating in California and the United States since 2022. This is the first time clade I cases without a history of international travel have been reported in California or the United States. All previous clade I mpox cases in California and the United States reported international travel to countries where clade I mpox was known to be spreading.

Mpox symptoms in clade I cases can be severe. The risk of severe disease and hospitalization is highest for people with weakened immune systems. Both clades may present with flu-like symptoms, followed by a rash, and are diagnosed through laboratory testing. For either clade, vaccination lowers the chances of getting mpox and having severe disease.

What you can do to protect ​yourself:

Both clades of mpox spread mostly through close personal contact, including sex.

• Get vaccinated if you may be at risk. CDPH recommends the mpox vaccine for any person who:

• If you are exposed to mpox: Get the mpox vaccine as soon as possible and before symptoms develop. Consider avoiding intimate contact for 21 days.

• If you develop symptoms of mpox: Talk to your health care provider right away so that you can get tested. Tell your doctor about any recent travel outside the United States.

• If you have mpox : Isolate at home and avoid contact with others until the rash is healed, clean and disinfect shared areas in your home, and notify people who may have been exposed.

• Avoid skin-to-skin contact or sharing items with people who have a rash or sores that look like mpox.

• If caring for someone with mpox: use masks, gowns, and gloves to protect yourself from getting infected.
  

If Sexually Active, Protect Yours​elf and Your Partner by:

• Not having sex or close contact if you or your partner(s) have mpox symptoms, such as a new or unexplained rash or sores or feels sick until they see a health care provider.

• Reducing the number of sexual or close contact partners, especially if their recent sexual history is unknown.

• Making a habit of exchanging contact info with any new partner for sexual health follow-up if needed.

• Limiting going to sex or circuit parties or spaces with intimate contact with multiple people.

• Using condoms and gloves during sexual activity:

• Not sharing toothbrushes, towels, clothing, bedding, fetish gear, or sex toys.

• Washing hands and all gear, towels, bedding and sex toys thoroughly after use or sex act.
  

Health Care Providers

Health care providers should incorporate assessments for mpox risk and vaccination status at all sexual health visits, and test patients with compatible signs and symptoms, regardless of vaccination status or previous infection.

Mpox prevention information is available on CDPH's Sexual Health Toolkits and Campaign Materials Page.

For more information on the recent clade I cases indicating community spread, see health alerts posted at California Health Alerts. CDPH will continue to closely monitor this situation and will provide updates as needed.