HAN: Mpox caused by human-to-human transmission of Monkeypox virus with geographic spread in the Democratic Republic of Congo

Distributed via the CDC Health Alert Network (HAN) on Dec. 7, 2023

The Centers for Disease Control and Prevention (CDC) is issuing this Health Alert Network (HAN) Health Advisory to notify clinicians and health departments about the occurrence, geographic spread, and sexually associated human-to-human transmission of Clade I Monkeypox virus (MPXV) in the Democratic Republic of the Congo (DRC).

MPXV has two distinct genetic clades (subtypes), and cases of Clade I MPXV have not been reported in the United States at this time (a clade is a broad grouping of viruses that has evolved over decades and is a genetic and clinically distinct group). However, clinicians should be aware of the possibility of Clade I MPXV in travelers who have been in DRC. Clinicians should notify their state health department if they have a patient with mpox-like symptoms, which may include a diffuse rash and lymphadenopathy, and recent travel to DRC. Clinicians should also submit lesion specimens for clade-specific testing for these patients.

Vaccines (e.g., JYNNEOS, ACAM2000) and other medical countermeasures (e.g., tecovirimat,
brincidofovir, and vaccinia immune globulin intravenous) are available and expected to be effective for
both Clade I and Clade II MPXV infections. However, vaccination coverage in the United States remains
low, with only one in four people who are eligible to receive the vaccine having received both doses of

CDC recommends that clinicians encourage vaccination for patients who are eligible.

Read the full advisory from the CDC here.