Hantavirus on the South Atlantic: A One Health and Microbiome Perspective on an Emerging Ecological Alert

In April–May 2026, a cluster of hantavirus pulmonary syndrome (HPS) cases occurred aboard the Dutch-flagged polar expedition cruise ship MV Hondius during a transatlantic voyage. As of May 13, 2026, the World Health Organization has reported eleven cases including three deaths, representing a case fatality rate of 27%. Genomic sequencing has confirmed Andes virus (ANDV)—the only hantavirus species known to exhibit limited human-to-human transmission. What makes this outbreak extraordinary is its setting: not a traditional agricultural or woodland environment, but a confined ship carrying 147 individuals from 23 countries, traversing the South Atlantic with stops at multiple remote and ecologically sensitive locations including the Antarctic Peninsula, South Georgia, and Tristan da Cunha. This event serves as a compelling ecological harbinger that the transmission patterns of traditionally zoonotic hantaviruses are being systematically reshaped by the rapid expansion of global travel networks and ongoing environmental transformations. Simultaneously, climate change and land-use shifts are fundamentally altering the composition and distribution of rodent communities, adding further complexity to the human–pathogen interface. As a newly launched international academic platform at the intersection of microbiome science and One Health, this journal advocates for breaking down disciplinary barriers among human health, animal health, and ecosystem health to understand the deeper logic of emerging infectious diseases. The 2026 cruise ship outbreak provides a unique prism through which to examine how biodiversity loss, climate change, host microbiome dysbiosis, and spatiotemporal mismatches in international travel synergistically generate emerging public health challenges.