Monkeypox Virus Surveillance - United States, 2024-2025

Since the onset of a global outbreak of monkeypox virus (MPXV) infections in 2022, cases have declined substantially in the United States; however, ongoing low-level transmission has persisted. To assess trends in cases of MPXV infection in the United States during 2024-2025, investigators analyzed data from the One CDC Data Platform and the National Notifiable Diseases Surveillance System. In 2024, a total of 2,803 cases of MPXV infection were reported in the United States, including one travel-associated clade Ib case. In 2025, a total of 2,519 cases were reported, including 10 clade Ib cases. The number of reported cases of MPXV infection during September-October 2025 was double that during the same period in 2024, although cases returned to background levels by the end of December 2025. Demographic characteristics of patients with MPXV infections, including distributions by sex, race and ethnicity, sexual orientation, lesion location, and age, were similar to those reported in previous years. Among 860 patients with complete information, the odds of hospitalization among those who were unvaccinated were 9.73 times those who were fully vaccinated when controlling for age group and HIV status. Encouraging completion of the recommended 2-dose vaccination series for persons at risk for MPXV exposure, including travelers to specific countries with ongoing clade I or clade II transmission, could reduce the risk for severe illness and hospitalization. Continued routine surveillance remains important to limiting future spread, monitoring changes in viral evolution, and focusing vaccination efforts on affected areas.