Mpox Resurgence of New Clade and Infection Control Strategies

The recent Monkeypox virus (Mpox) infection pandemic is thought to be caused by a combination of factors, including decreased herd immunity due to the cessation of smallpox vaccination and viral genetic evolution.It has shown a dynamic pattern that has led the World Health Organization to declare a Public Health Emergency of International Concern twice.Mpox is now accepted as a new re-emerging infectious disease that has never been experienced before.The 2022 outbreak of Clade IIb mainly spread through sexual contact among men who have sex with men, transgenders, and bisexuals, and most patients recovered with conservative treatment while progression to severe disease was observed only in immunocompromised state, such as untreated HIV-infected individuals.A Clade b outbreak occurred in Africa in 2024, especially in the Democratic Republic of Congo (DRC), among various groups, such as children and adolescents, sex workers, and men who have sex with men.While the relatively high case fatality rates have been reported in some countries or regions, the overall fatality rate is estimated to be less than 1% overall.The outbreak in the DRC has been relatively stable since April 2025, and the number of newly confirmed cases is increasing in Uganda and Sierra Leone.Clade b cases have been reported in about 10 countries outside of Africa, almost all involving travel to the endemic areas.In Korea, the highest monthly number of newly confirmed cases (48) was reported in May 2023, and sporadic cases have been reported since 2024.As there is no robust treatment modality against Mpox, close monitoring of domestic and international situations is necessary, and preparedness for timely enhancement strategies for resource allocation and vaccination is crucial.