U.S. CDC issues alert as mpox outbreak in Central, East Africa leads to new cases in the U.S.
May 31, 2025
The CDC’s recent health alert underscores the seriousness of the Clade I mpox outbreak in Central Africa, particularly the Democratic Republic of the Congo. Although no sustained U.S. transmission has occurred, travel-linked cases signal a need for vigilance. Clade I is more severe than its Clade II counterpart and has caused fatalities abroad. Healthcare providers must be proactive—screening travelers, reporting suspected cases, and encouraging vaccination. The JYNNEOS vaccine remains protective against both clades. Now is not the time for complacency. Early detection and vaccination outreach are key to preventing a domestic resurgence of a more dangerous strain.
The Centers for Disease Control and Prevention (CDC) has issued a Health Alert Network (HAN) advisory warning clinicians of growing mpox activity in Central Africa, specifically involving Clade I of the virus. Known for its higher fatality rate and more severe symptoms than Clade II—the variant responsible for the 2022–2023 global outbreak—Clade I poses a serious public health threat, particularly as travel-related cases begin surfacing in the United States.
Genetic sequencing confirms that recent U.S. cases are linked to strains circulating in the Democratic Republic of the Congo (DRC). While no sustained community transmission has occurred domestically, the CDC warns that the outbreak in the DRC involves significant human-to-human spread, including among children and women—marking a shift from prior outbreaks largely affecting men who have sex with men.
Healthcare providers are urged to include mpox in their differential diagnoses for patients presenting with compatible symptoms and recent travel to affected regions. Early identification, prompt specimen collection, and immediate reporting are vital tools in forestalling wider transmission.
Vaccination remains the strongest preventive measure. The JYNNEOS vaccine protects against both Clade I and Clade II, yet uptake has waned. Public health agencies must intensify outreach to ensure that vulnerable populations—especially recent travelers—are tested, treated, and vaccinated. With over 100,000 mpox cases globally since 2022 and mounting cases in Central Africa, the stakes are clear.
The CDC has not imposed travel restrictions but advises travelers to avoid contact with sick individuals, wild animals, and contaminated materials. The emphasis is on preparation, not panic. The U.S. must act decisively to avoid repeating the oversight that allowed Clade II to spread globally. With Clade I’s more dangerous profile, robust surveillance, vaccine delivery, and inter-agency coordination are not optional—they are essential.