On April 14, 2026, the first clade I mpox case in San Francisco was confirmed. The case occurred in an unvaccinated adult. The individual reported close contact with someone who traveled internationally to an area where clade I mpox is circulating.

Find more information about clade I mpox for San Francisco providers.

Approach to most patients

Supportive care and symptomatic treatment is sufficient for most patients. This includes pain relievers and benzocaine/lidocaine gels for painful proctitis. In rare cases a patient may need pain management beyond over the counter pain relivers.

There is no FDA-approved treatment for clade I or clade II mpox infection.

Tecovirimat (TPOXX) monotherapy was not found to be effective for patients with mild to moderate mpox in the STOMP Trial. The trial was stopped in November 2024 after an interim analysis showed that tecovirimat, while safe, did not shorten the time to lesion resolution or reduce pain compared to placebo among persons with mild to moderate clade II mpox.

Approach to patients with severe immunocomprise or at risk for severe disease

For patients with severe immunocompromise or who are at risk for severe disease, consider use of tecovirimat in combination with other therapeutics, such as brincidofovir.

Patients at risk for severe disease include:

• Patients with immunocompromising conditions or on immunosuppressive medications
• Patients with protracted or life-threatening manifestations of mpox
• Patients with active skin conditions that place them at higher risk for disseminated infection
• Pregnant and lactating patients
• Children

Tecovirimat is available through an Expanded Access Investigational New Drug (EA-IND) protocol for the treatment of mpox for patients who meet CDC criteria (e.g., persons with or at high risk for protracted or life-threatening diseases, pregnant or lactating persons, and children).

How to prescribe tecovirimat

1. Review the Expanded Access Investigational New Drug (EA-IND) protocol to check that your patient meets eligibility criteria.
2. Register on the CDC TPOXX IND Registry the first time you prescribe tecovirimat.
3. Fill out all required forms listed on the CDC website each time you prescribe tecovirimat.
4. Acquire tecovirimat in your practice. If your practice does not already stock tecovirimat, contact us to request it for your patient.

How to prescribe brincidofivir or other therapeutics

• Learn more about available therapeutics for mpox from the CDC.
• Contact us for help with prescribing and acquiring brincidofivir and other therapeutics.

Test for the virus and the clade

Mpox is diagnosed using real-time PCR tests performed on lesion swabs. When testing for monkeypox virus, order at minimum the following:

1. Non-variola orthopoxvirus (NVO) PCR or Monkeypox virus PCR, and
2. Clade II monkeypox virus PCR

Both tests can be performed on the same set of 2 swabs.

Ordering Clade II monkeypox PCR in addition to NVO PCR or Monkeypox virus PCR enables identification of suspected clade I mpox. Clade II monkeypox testing is not currently available via Labcorp; consider using another laboratory for this test.

• If your patient's lesion swabs return NVO positive and clade II negative, contact SFDPH to arrange for clade I testing.

Learn more about mpox diagnostic testing from the CDC.

Swab lesions vigorously, but do not unroof them

• Vigorous swabbing ensures enough cells are available for testing.
• Unroofing, aspirating, or lancing lesions is not recommended due to the risk for sharps injury.

Learn more about specimen collection from the CDC.