• New CDC guidance (Feb 23) in MMWR on Clinical Treatment Recommendations for Severe Manifestations of MPOX. The guidance describes current experience and data, reinforces LA DPH recommendations, and includes a helpful algorithm, therapy summary table, and management information for specific organ system dysfunction.
• Healthcare providers should call the LAC DPH consultation line if a hospitalized patient is worsening clinically, such as being admitted to the ICU. LAC DPH will provide clinical consultation and access to additional therapeutic options.

Many people infected with mpox have a mild, self-limiting disease course and recover without the need for antiviral medication. However, the prognosis for mpox depends on multiple factors, such as disease severity, risk factors for severe disease, location of lesions, previous vaccination status among others. Severe outcomes have been observed in people with inadequately treated or advanced HIV. Providers should determine the HIV status of all sexually active patients with mpox (see Considerations in People with HIV) below.

Supportive care and pain control should be initiated early for all patients with suspect or confirmed mpox infection. This may include different topical, systemic medications, or other clinical interventions to ameliorate symptoms such as pain, itching, and nausea. Proctitis can occur and progress to become severe and debilitating, that may require prescription medication. Bacterial superinfection may be present and require antibiotics and drainage for abscesses.

All patients should be provided with instructions on lesion management and return precautions for worsening disease.

For details see CDPH Supportive Care Suggestions for Patients with Mpox.

Tecovirimat (also known as TPOXX or ST-246) is an FDA-approved antiviral medication for the treatment of human smallpox disease. Tecovirimat is available in oral and intravenous formulations. The CDC holds an expanded access Investigational New Drug (EA-IND) protocol that allows for the use of stockpiled tecovirimat to treat mpox disease during an outbreak. Informed consent is required for all patients treated with tecovirimat and providers must follow the CDC EA-IND protocol.

Treatment with tecovirimat is recommended for the following patients with mpox:

• Those with severe disease- such as hemorrhagic disease; large number of confluent lesions; sepsis; encephalitis; ocular or periorbital infections; or other conditions requiring hospitalization
• Those with involvement of anatomic areas that might result in short term or longer term sequelae— these include lesions directly involving the pharynx causing dysphagia, inability to control secretions, or need for parenteral feeding; penile foreskin, vulva, vagina, urethra, or rectum with the potential for causing strictures or requiring catheterization; anal lesions interfering with bowel movements (for example, severe pain); and severe infections (including secondary bacterial skin infections), especially those that require surgical intervention such as debridement.
• People who are at high risk for severe disease such as:
  • Those with severe immunocompromise due to conditions such as advanced or poorly controlled HIV, leukemia, lymphoma, generalized malignancy, solid organ transplantation, therapy with alkylating agents, antimetabolites, radiation, tumor necrosis factor inhibitors, or high-dose corticosteroids, being a recipient of a hematopoietic stem cell transplant <24 months post-transplant or ≥24 months but with graft-versus-host disease or disease relapse, or having autoimmune disease with immunodeficiency as a clinical component
  • Pediatric populations, particularly patients younger than 8 years of age
  • Pregnant or breastfeeding people
  • People with a condition affecting skin integrity — conditions such as atopic dermatitis, eczema, burns, impetigo, varicella zoster virus infection, herpes simplex virus infection, severe acne, severe diaper dermatitis with extensive areas of denuded skin, psoriasis, or Darier disease (keratosis follicularis)

For patients at high risk for progression to severe disease, tecovirimat should be administered early in the course of illness along with supportive care and pain control. Treatment may be initiated empirically if the suspicion for mpox is high while lab confirmation is pending.

Data are not available on the effectiveness of tecovirimat in treating mpox infections in people, but studies using a variety of animal species have shown that tecovirimat is effective in treating disease caused by orthopoxviruses. Clinical trials in people showed the drug was safe and had only minor side effects. A recent report from CDC found that that it was well tolerated and that the median time to subjective improvement was three days (however there was no control group).

While clinical resistance to tecovirimat has not been reported, additional in vitro data suggests multiple mutations conferring resistance can rapidly emerge. As with any antimicrobial, CDC guidance emphasizes the importance of stewardship principles including using tecovirimat in patients where appropriate. Educating patients on the importance of adherence to the full treatment course, including anticipating the possible side effects of tecovirimat, is also critical to minimizing selection pressure.

Tecovirimat should be access through enrollment in the STOMP trial. Please see below information. If the patient does not consent to enrollment, TPOXX is positioned at Disaster Resource Center umbrella hospitals, with most major medical networks, and selected outpatient pharmacies. Providers without onsite access to the drug can use the LAC DPH TPOXX Treatment Checklist for Providers to prescribe TPOXX through an outpatient community pharmacy. If you need assistance with access to TPOXX please call LAC DPH.

For additional details see CDC Guidance for Tecovirimat Use Under Expanded Access Investigational New Drug Protocol during 2022 U.S. Mpox Outbreak.

Clinicians who suspect outpatient treatment failure, for example failure to improve or the appearance new lesions while on treatment, should re-examine the patient. If the concern for treatment failure is confirmed please collect new swabs for specialized testing through our public health lab and contact LAC DPH for authorization and clinical consultation. Repeat HIV testing should also be considered. Worsening, non-healing, recurrent, and new skin lesions while receiving antiviral treatment have been observed among immunocompromised patients who otherwise remain stable. In such cases, clinicians should discuss with DPH and consider continuing tecovirimat beyond 14 days, until there is clinical improvement (no more than 90 days).

Clinicians must report hospitalizations due to mpox to LAC DPH. In addition, please call the LAC DPH consultation line if a hospitalized patient is worsening clinically, such as being admitted to the ICU. LAC DPH will provide clinical consultation, and if needed arrange CDC consultation and facilitate access to additional therapeutic options. Intravenous tecovirimat should be used in patients who are unable to take oral therapy, who may have impaired oral drug absorption, or who are failing to improve on oral therapy.

In severe disease, additional treatment options are available including cidofovir/brincidofovir and vaccinia immune globulin.

• Brincidofovir is an oral pro-drug of cidofovir without the renal toxicity and other adverse effects observed with cidofovir. It is approved for the treatment of smallpox.
• Cidofovir is an intravenous antiviral medication approved for the treatment of CMV retinitis with in vitro and animal efficacy against orthopoxviruses.
• Vaccinia immune globulin is licensed for complications of vaccinia vaccination.

Access can be arranged through LAC DPH.

See CDC Mpox Treatment Information for more details.

During the current outbreak in the US, the CDC reports that 38% of people diagnosed with mpox were coinfected with HIV and most known cases of mpox with severe manifestations have been among people living with untreated HIV.

People with advanced or uncontrolled HIV are at risk of life-threatening mpox disease. In prior mpox outbreaks in Nigeria, co-infection with HIV was associated with worse clinical outcomes, including severe manifestations of mpox, hospitalization, and death. Per CDC, of the people with severe manifestations of mpox for whom CDC has been consulted during the current outbreak, the majority have had HIV with CD4 counts <200 cells/ml, indicating substantial immunosuppression.

Providers should consider both the patient’s CD4 count and viral load when assessing the risk of severe disease, however there is insufficient data to define actionable thresholds. Severe outcomes have been observed in people with inadequately treated HIV who have CD4 counts less than or equal to 350/mm3. Clinical judgment should be used to best determine the degree of risk.

For people diagnosed with HIV coincident with mpox or who are not taking ART, CDC recommends starting ART as soon as possible and in consultation with an expert in HIV medicine if needed. See CDC Clinical Considerations for Treatment and Prophylaxis of Mpox Virus Infection in People with HIV for more details. Tecovirimat may affect the drug levels of some antiretroviral treatments (ART), but some experts believe neither dose adjustments nor additional ART are needed. Further information is available through the Liverpool HIV Drug Interaction Database and the Johns Hopkins HIV Guidelines.

New HIV diagnoses or out of care patients may be referred to the Los Angeles County Rapid and Ready Program by calling 833-351-2298 during weekdays 8am to 5pm or by emailing rapid@ph.lacounty.gov.