Abstract
WHAT IS ALREADY KNOWN ABOUT THIS TOPIC? Monkeypox virus (MPXV) is an orthopoxvirus comprising two major genetic clades: clade Ⅰ (subclades Ⅰa and Ⅰb) and clade Ⅱ (subclades Ⅱa and Ⅱb). The 2022-2023 global outbreak was predominantly driven by clade Ⅱb. Clade Ⅰ viruses remain endemic in Central Africa, particularly Democratic Republic of the Congo (DRC), and are historically associated with higher virulence and fatality rates. WHAT IS ADDED BY THIS REPORT? Two imported MPXV cases were detected in Shanghai via real-time polymerase chain reaction (PCR) in 2025, both originating from DRC. Clade-specific PCR and whole-genome sequencing identified clade Ⅰa. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE? These cases underscore the ongoing risk of MPXV importation through international travel. The successful detection and management of these clade Ⅰa infections demonstrate the critical importance of port entry screening, enhanced surveillance systems, and coordinated multi-agency prevention and control strategies.