ALLIANCE FOR INTERNATIONAL MEDICAL ACTION

First U.S. Case of More Virulent Mpox Strain Detected in California Traveler

• California health officials have confirmed the first U.S. case of the more virulent "clade Ib" mpox strain in a traveler returning from Africa, where the variant has caused widespread outbreaks. • The infected individual is isolating at home and recovering, with public health workers contacting those who had close contact, though officials state there is no evidence of local transmission. • While historically more severe than the clade II strain that circulated globally in 2022, recent data suggests the current clade I outbreak may cause less severe illness than in previous outbreaks, with death rates potentially much lower in countries with robust healthcare systems.