UC Irvine Department of Medicine

The Andes Virus (ANDV) outbreak reported on 2 May 2026 aboard a luxury vessel departing from Ushuaia, Patagonia, Argentina, was caused by an Orthohantavirus that is unique in its person-to-person transmissibility in contrast to zoonotic transmission characteristic of better-known hantaviruses. Outbreak containment requires coordinated international management because passengers and crew embarked and disembarked at several international ports of call prior to outbreak recognition, resulting in cross-border transmission potential. Among those who disembarked, several traveled on flights to various international destinations. Cases have subsequently been identified in multiple countries, including the Tristan da Cunha (United Kingdon territory), Spain, France, Switzerland, South Africa, and Canada. International health authorities implemented containment measures once notified, including contact tracing, quarantine, and isolation.

ANDV poses unique risks due to its immediately prodromal presymptomatic transmission potential, initial non-specific flu-like symptoms, prolonged incubation period, high case fatality rates, and potential for international dissemination. This report describes a multinational outbreak associated with cruise ship travel and examines its implications and challenges for prehospital, healthcare facility, and public health systems. The event was characterized by delayed recognition, international spread, and complex coordination across multiple jurisdictions and sectors, including medical and public health authorities, policy- and decision-makers, crisis and emergency risk communication experts, logistics, transportation, and security.

Rapid implementation of public health measures coupled with clinician implementation of the Identify-Isolate-Inform (3I) model at the prehospital and healthcare facility levels are critical actions that can contain ANDV transmission and prevent a pandemic.

posted May 20, 2026; updated May 21, 2026; updated June 2, 2026