Andes Hantavirus Spreading North in Argentina as Climate Change Alters Rodent Habitats; 2025–2026 Season Sees Record Cases

Argentina is experiencing a record hantavirus outbreak during the 2025–2026 season, with 101 confirmed cases and 32 deaths—substantially exceeding the typical annual burden of ~80 cases and ~20 deaths. The Andes strain, endemic to Patagonia and lethal in over 30% of infections, has expanded its geographic range as climate change has altered precipitation and vegetation patterns, driving rodent populations northward into more densely populated regions. Buenos Aires province alone has recorded 42 infections and 16 deaths. While human-to-human transmission of ANDV is possible but limited, the virus poses no global pandemic threat. However, the outbreak underscores how rapidly changing climate conditions can shift zoonotic disease distributions and increase human exposure in urban settings. Travelers to affected areas are advised to exercise precautions.