Mpox caused by sexually associated human-to-human transmission of monkeypox virus Clade I in the Democratic Republic of the Congo

Actions requested

• Be aware of the occurrence, geographic spread, and sexually associated person-to-person transmission of Clade I Monkeypox virus (MPXV) in the Democratic Republic of the Congo (DRC).
• MPXV has two distinct genetic clades with Clade IIb associated with the 2022–23 global outbreak that has predominately affected gay, bisexual, and other men who have sex with men (MSM).
• MPXV Clade I has been previously associated with non-sexual routes of transmission and observed to be more transmissible and cause more severe infections than Clade II.
• Clade I MPXV infections have not been detected in the United States so far and the current threat for Clade I MPXV in travelers to the United States remains low.
• Vaccines (e.g., JYNNEOS) and other available medical countermeasures (e.g., tecovirimat) are expected to be effective for both Clade I and Clade II MPXV infections.
• Clade IIb MPXV infections continue to be reported in the United States, reflecting ongoing community transmission, including in King County, WA where 33 mpox cases have been reported since September 2023.
• Notify Public Health (206-296-4774) immediately if you have a patient with mpox-like symptoms, which may include a diffuse rash and lymphadenopathy, and recent travel (within 21 days of illness onset) to the DRC.
• Clinicians should work with Public Health to submit lesion specimens for clade-specific testing for these patients.
• Continue to recommend vaccination with a complete 2-dose series of JYNNEOS for people at greater risk for MPXV infection.
• Vaccination against mpox remains an important risk-reduction measure.
• Patients who have recovered from mpox (Clade II MPXV) or have been previously vaccinated with JYNNEOS are expected to have cross-protection to Clade I MPXV.
• If the vaccine is not available in your clinic, share the CDC vaccine finder with your patients.
• People who previously received only one JYNNEOS vaccine dose should receive a second dose as soon as possible.
• People who develop mpox after completing a two-dose JYNNEOS vaccine series may experience less severe symptoms than those who have not completed the vaccine series.
• Avoid conducting extensive risk assessment in people who request vaccination to avoid stigma and other barriers experienced by those who could benefit from vaccine.
• Mpox vaccine may also be given as post-exposure prophylaxis (PEP) to people who are not already fully vaccinated and who have not already had mpox who present with known or presumed exposure to MPXV. As PEP, vaccine should be given as soon as possible, ideally within 4 days of exposure but administration 4–14 days after exposure may still provide some protection against mpox.
• Additional vaccine administration considerations for specific populations are available on the CDC website.
• Refamiliarize yourself with mpox symptoms, specimen collection, laboratory procedures, and treatment options.
• Consider mpox when determining the cause of a diffuse or localized rash, including patients who were previously infected with mpox or vaccinated against mpox.
• Perform a complete physical examination, including a thorough skin and mucosal (e.g., oral, genital, anal) examination which may reveal lesions of which the patient was unaware.
• Mpox may present differently in those who were previously vaccinated. Lesions can be few and isolated, pain or discomfort in the throat or rectum can occur with or without classic lesions, and fevers can be absent.
• Patients benefit from individually tailored supportive care and pain management strategies.
• Continue to consider tecovirimat (also known as TPOXX or ST-246) as first-line therapy for patients with especially among those with severe complications, severe disease or who are at high risk for severe disease.
• Encourage patient enrollment both in person and remotely into the STOMP STUDY for recently diagnosed and symptomatic mpox patients to evaluate treatment of oral tecovirimat.