Related Materials: Latest CDC Mpox Health Alert (cdc.gov) | Latest California Mpox Health Alert | CDC Health Alert Network (HAN) | California Health Alert Network (CAHAN) | Mpox Q&A
The California Department of Public Health (CDPH) continues to work with local health departments (LHDs) and California health care providers on the ongoing mpox outbreak impacting the United States and other countries not usually endemic for mpox. Reports from investigations in several countries and the U.S., including in California, suggest that person-to-person transmission through close contact is fueling spread, and that clinical case presentations have not always been characteristic of classic mpox infections.
Mpox 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. Mpox can spread during intimate contact between people, including during sex, as well as activities like kissing, cuddling, or touching parts of the body with mpox sores. At this time, it is not known if mpox can spread through semen or vaginal fluids. A persons should be considered a suspect case if they have a new characteristic rash OR if they have risk factors for mpox exposure and clinical suspicion for mpox. Features of the typical disease course are shown below:
Symptom Monitoring or Isolation?
3 – 17 days
Monitor for symptoms
1 – 4 days
2 – 4 weeks
4 weeks or longer
* A person is contagious until after all the scabs on the skin have fallen off and a fresh layer of skin has formed
The rash associated with mpox classically involves vesicles or pustules that are deep-seated, firm or hard, and well-circumscribed; the lesions may umbilicate or become confluent and progress over time to scabs. However, presentations in this outbreak have not always been classic. Patients have experienced rashes without prodromal symptoms, rashes that are at different stages within an affected area, or rashes that do not involve the face or extremities but only the genital and/or perianal areas.
Clinicians should perform a thorough skin and mucosal (e.g., anal, vaginal, oral) examination for the characteristic vesicular or pustular rash of mpox; this allows for detection of lesions of which the patient may not have previously been aware.
Figure 1: Examples of mpox lesions, from CDC Health Alert Network 6/14/2022
Figure 2: Photo credit – General Hospital University of Malaga
More supportive of Mpox
Less supportive of Mpox
1. Did the patient have a prodrome (fevers, chills, headache, lymphadenopathy, flu-like symptoms)?
Yes: recent cases have presented without an obvious prodrome. However, a patient with a strong epidemiologic link PLUS prodromal symptoms might increase suspicion of mpox. Notably lymphadenopathy is a distinguishing feature of mpox.
No: recent cases have presented without an obvious prodrome. A patient with an epidemiologic link without prodromal symptoms might decrease suspicion of mpox – close monitoring should occur for development of a rash or other symptoms.
2. Did the patient develop a rash?
Yes: all cases to date in California have developed a rash at some point in their course.
No: some cases have developed anorectal pain, tenesmus or bleeding, but these were from non-visible perianal lesions.
3. Where is the rash?
Uncertain: Classically, mpox rashes have started in the face and extremities then spread to rest of body. In recent cases, 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.
4. What is the rash appearance?
Deep-seated and well-circumscribed lesions, often with central umbilication. Lesions progress through specific sequential stages, sometimes rapidly—macules, papules, vesicles, pustules, and scabs.
Other presentations of rashes and rashes that do not progress. Remember, rashes in certain stages can be mistaken for other common rash etiologies, including sexually transmitted diseases (STDs) such as syphilis, herpes, etc.
5. Is the stage of rash consistent within each body part?
Uncertain: Although lesions on each part of body classically are at the same stage, recent cases have had rashes at different stages of progression in the same part of the body.
6. Is the rash painful?
Yes: mpox rash is sometimes very painful and is often a reason people seek treatment.
No: Rashes such as those associated with HSV can be painful however other STDs such as syphilis are not typically painful.
7. Did the patient test positive for other rash etiology?
No: negative test for other etiologies that cause rashes that appear similar to mpox (e.g., VZV, HSV, syphilis). Coinfections have been seen with STDs, particularly syphilis, so positive test for an STI may not completely rule out mpox.
Yes: positive test for other rash etiology, especially one that cause rashes that appear similar to mpox. Coinfections with STDs, particularly syphilis, have occurred in recent cases, so a positive test does not rule out mpox.
8. Was there contact with a known or suspect mpox case?
Contact with lesions or bodily fluids Sexual Contacts Household Contacts Prolonged (3 hours+) unmasked contact within six feet
Masked contact within 6 feet Contact with lesions/bodily fluids while wearing PPE. Shared airspace contact >6 feet
9. Did the patient recently participate in parties or gatherings involving sex, especially with multiple sex partners? Or did the patient participate in intimate contact at venues where there is sex on premises such as bathhouses or saunas?
Yes: there have been a number of cases and contacts associated with sex or extended physical contact in sex related events, or bathhouses/saunas, with multiple sex partners.
No: no participation or contact with someone who has participated in these activities or attended these venues/events is less suggestive of mpox.
10. Is the patient part of a social group known to have high mpox incidence or risk?
Yes: the majority of cases seen so far in non-endemic countries have been in men or transgender persons who have sex with men.
No: no known linkage to a high-risk group or reported high-risk social or sexual behaviors would be less suggestive of mpox.
*While some of the listed factors more strongly suggest an underlying mpox etiology, no one answer is absolute in determining whether to suspect mpox; instead, the collective responses and overall clinical picture should be considered.
Importantly, any patient who is a suspect case should be counseled to implement appropriate transmission precautions, including isolation, immediately while awaiting testing results. The CDC's updated guidance for Isolation and Infection Control at Home and Duration of Isolation Procedures and CDPH's updated isolation guidance provide direction on how people can protect themselves and their communities.
It is still unknown if mpox can be transmitted via genital secretions, patients should be counseled on use of condoms during sexual activities. Research is ongoing regarding how long people should use condoms after recovering from mpox, but some countries are recommending a minimum of 8 weeks of condom use after recovery.
Health care providers must report cases of persons meeting the definition of a Suspect Case (Case Definitions† for Use in the 2022 Mpox Response | Mpox | Poxvirus | CDC) to their LHD, as this will be added to the list of required reportable diseases and conditions in 2022.
Please refer to the CDC guidance for the preparation and collection of specimens for details: Preparation and Collection of Specimens | Mpox | Poxvirus | CDC.
The JYNNEOS vaccine is approved by the U.S. Food and Drug Administration (FDA) to prevent both mpox and smallpox. At this time, the federal government has allocated a limited number of JYNNEOS vaccine doses to Californians. CDPH is working with LHDs to make these doses available to protect against mpox. The CDPH vaccine page and JYNNEOS Q&A has additional information and guidance about the vaccine. Contact your LHD for more information in ordering the vaccine.
Health care providers seeing persons with suspected or confirmed mpox should provide supportive care and treatment of symptoms. This may include medicines or other clinical interventions to control itching, nausea, vomiting, and pain. For additional information on supportive care, please see CDPH’s Supportive Care Guidance.
Providers should consider treating high-risk suspect or confirmed cases who have pending lab testing results with tecovirimat (TPOXX), an antiviral medication available through an expanded access Investigational New Drug (EA-IND) protocol for the treatment of mpox infection. Antiviral treatment of mpox infection should be considered for patients with severe infection, illness complications, and risk factors for progression to severe infection (children <8 years of age, pregnant or immunocompromised individuals, or those with a history of atopic dermatitis or eczema). Contact your LHD if you need information about sites where you can refer your patient. For additional information regarding tecovirimat treatment, please see CDPH's treatment guidance for providers.
Treatment Information for Healthcare Professionals | Mpox | Poxvirus | CDC
Clinical Considerations for Mpox in Children and Adolescents | Mpox | Poxvirus | CDC
CDC Testing Directory
CDC Clinician FAQs
Mpox fact sheet for sexually active persons
CDPH Mpox Communications Toolkit
HAN Archive - 00468 | Health Alert Network (HAN) (cdc.gov)
2022 United States Mpox Case | Mpox | Poxvirus | CDC
CDC Personal Protective Equipment Sequence
WHO Mpox Fact Sheet
BHOC Mpox Information for Gay, Bi, and Trans People Who May Be Exposed Through Sex and Intimate Contact