Trader consensus on Polymarket implies a 75.5% probability that the CDC will issue at least one Level 3 Travel Health Notice—recommending travelers reconsider nonessential trips due to high outbreak risk—by December 31, 2026, driven primarily by the early May hantavirus outbreak aboard the MV Hondius cruise ship in the South Atlantic, where Andes virus caused at least three deaths among passengers and prompted CDC Emergency Operations Center activation at its routine Level 3 tier for monitoring dispersed U.S. contacts across multiple countries. No Level 3 notices are currently active per CDC's May 7 update, but several Level 2 enhanced precautions persist for clade II mpox in Ghana and Liberia, meningococcal disease in the Democratic Republic of the Congo, global polio, and chikungunya outbreaks, any of which could escalate amid uncertain transmission dynamics. Persistent H5N1 avian influenza reservoirs in wild birds and poultry—with no new U.S. human cases reported in FluView week 17 ending May 2—add baseline risk, alongside seasonal disease surveillance updates expected weekly.