International Response to 2026 Andes Virus Outbreak on Cruise Ship Highlights the Value of Cross-Border Scientific Networks, According to Newly Published Article

International Response to 2026 Andes Virus Outbreak on Cruise Ship Highlights the Value of Cross-Border Scientific Networks, According to Newly Published Article

Article in The Lancet describes how scientific and public health capabilities developed in South America contributed to the international response

A new article, published August 22 in The Lancet, describes how scientists, public health institutions, and international organizations worked across national borders to respond to the 2026 hantavirus outbreak associated with the MV Hondius cruise ship, drawing on scientific and diagnostic capabilities developed in South America over many years.

The article, led by Gustavo Palacios, PhD, Professor of Microbiology at the Icahn School of Medicine at Mount Sinai, and co-authored by scientists from Argentina, Chile, and Uruguay, examines the multinational response to an outbreak of hantavirus pulmonary syndrome caused by Andes virus.

The MV Hondius departed Ushuaia, Argentina, on April 1, 2026. The index case developed symptoms on April 3 and died eight days later; additional passengers and crew subsequently developed compatible illness. Upon arrival in Tenerife on May 10, symptomatic individuals were isolated and tested, while asymptomatic passengers were repatriated to quarantine. The outbreak comprised twelve confirmed Andes virus cases and one probable case, including three deaths.

The investigation of the MV Hondius outbreak brought together scientists and public-health institutions from Argentina, Chile, and Uruguay, who worked closely with international global partners (see list below) as well as regional partners in the Americas, including the U.S. Centers for Disease Control and Prevention, the Pan American Health Organization, and the World Health Organization. The Icahn School of Medicine played a critical role in supporting and coordinating the response among these international and regional teams.

The response required epidemiological and environmental investigations across multiple locations in South America, reconstruction of the movements of "patient zero", laboratory analysis, and rapid exchange of scientific information among institutions and countries. One of the most significant aspects of the response was that scientific resources developed in South America, where the hantavirus is endemic, were made available internationally.

Argentina supplied laboratories outside the region with reagents, materials, and technical resources, including Andes virus RNA, diagnostic protocols, and ELISA plates, a specialized laboratory tool. They provided enough reagent supplies for nearly 6,000 tests across 13 countries. Chile's contribution focused on clinical management guidance as well as specific monoclonal antibodies. This cooperation was later extended to additional countries.

"The MV Hondius outbreak response showed what is possible when scientific expertise, public health institutions, and international partners are able to work together across borders," said Dr. Palacios. "The region already had considerable knowledge and experience with Andes virus. The response showed the value of being able to connect those capabilities quickly across institutions and countries when they were needed."

Dr. Palacios leads a lab within the Department of Microbiology and the Global Health and Emerging Pathogens Institute at Mount Sinai. During the MV Hondius outbreak investigation, Dr. Palacios and his team played a scientific coordinating role, helping connect expertise and teams across institutions and countries as the response evolved.

According to Dr. Palacios, the experience illustrates a broader principle of outbreak preparedness: the ability to respond rapidly during an emergency depends not only on technologies and infrastructure, but also on scientific expertise, transparency, relationships, and trust that have been established long before an emergency occurs.

The response to the MV Hondius outbreak was built on decades of scientific work on Andes virus in South America, including research into its unusual capacity for person-to-person transmission, its genomic epidemiology, and the biological factors associated with transmission.

Dr. Palacios and his collaborators have previously contributed to studies reconstructing person-to-person transmission of Andes virus during outbreaks in Argentina and to research examining viral characteristics associated with transmission.

"Preparedness is not binary," Dr. Palacios said. "There is always more that can be done. But the MV Hondius outbreak demonstrated that significant scientific and operational capacity already exists across South America. Strengthening the connections between those capabilities can leave both the local region and the international community better prepared for future outbreaks."

The experience also highlights the importance of maintaining and strengthening scientific relationships over time. Networks established before an emergency can allow information, diagnostic resources, technologies, and expertise to move rapidly between laboratories, institutions, and countries when an emerging infectious-disease event occurs.

The article, titled "Hantavirus outbreak: a model of regional and global cooperation," was authored by Gustavo Palacios, PhD, Icahn School of Medicine at Mount Sinai; Nicole D. Tischler, PhD, Universidad San Sebastian; Adriana Delfraro, PhD, University of the Republic in Montevideo, Uruguay; Daniel. M Cisterna, PhD, Instituto Nacional de Enfermedades Infecciosas;, and Claudia Perandones, PhD, Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán".

Comprehensive list of Institutions participating in the MV Hondius investigations (in alphabetical order)

Argentina:

• Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán" (ANLIS-Malbrán), including the Instituto Nacional de Enfermedades Infecciosas, National Reference Laboratory for Hantaviruses, Department of Virology, and Department of Epidemiology

• Ministerio de Salud de la Nación, Dirección de Epidemiología

• Ministerio de Salud de la Provincia del Neuquén, including Hospital de San Martín de los Andes, Hospital Junín de los Andes, and Salud Ambiental Junín de los Andes

• Dirección de Epidemiología de Tierra del Fuego, Antártida e Islas del Atlántico Sur

• Ministerio de Salud, Desarrollo Social y Deportes, Gobierno de Mendoza, Dirección de Epidemiología y Gestión Integral de la Calidad en Salud

Belgium:

• European Plotkin Institute for Vaccinology, Université Libre de Bruxelles

Canada

• BC Centre for Disease Control Public Health Laboratory

• National Microbiology Laboratory, Public Health Agency of Canada, Special Pathogens Program

Chile

• Pontificia Universidad Católica de Chile

• Red Salud UC-Christus

• Fundación Ciencia & Vida and Centro Ciencia & Vida

• Universidad San Sebastián

• Centro de Estudios Científicos

• SENTINET

France

• Institut Pasteur

• Université Paris Cité

• Université Sorbonne Paris Nord

• Inserm and the IAME research unit

• Assistance Publique-Hôpitaux de Paris and Hôpital Bichat-Claude-Bernard

Germany

• Heidelberg University, Institute for Mathematics

• Karlsruhe Institute of Technology, Institute for Biological Interfaces 5

Netherlands

• Erasmus Medical Centre and the Pandemic and Disaster Preparedness Research Centre

• Leiden University Medical Center

• Radboud University Medical Center

• National Institute for Public Health and the Environment

• Amsterdam University Medical Center

• University Medical Center Utrecht

Senegal

• Institut Pasteur de Dakar

South Africa

• National Institute for Communicable Diseases, National Health Laboratory Service

• University of Pretoria

Spain

• Instituto de Salud Carlos III, including the National Center for Microbiology, Bioinformatics Unit, Genomics Unit, and Laboratory of Arboviruses and Imported Viral Diseases

• Centro de Investigación Biomédica en Red de Enfermedades Infecciosas

• Hospital Central de la Defensa "Gómez Ulla"

Switzerland

• Geneva University Hospitals

• University of Geneva

• University Hospital Zurich

• University of Zurich

United States

• Icahn School of Medicine at Mount Sinai, including the Department of Microbiology and Global Health Emerging Pathogens Institute

• Columbia University, including the Program of Mathematical Genomics, Department of Systems Biology, and Department of Biomedical Informatics

• U.S. Centers for Disease Control and Prevention.

Uruguay

• Universidad de la República, Facultad de Ciencias, Sección Virología

• Ministerio de Salud Pública, including the División Epidemiología, and Unidad de Zoonosis y Vectores

International and regional organizations

• World Health Organization, including headquarters, the Health Emergencies Programme, the Regional Office for Africa, the Regional Office for Europe, and country offices involved in the response

• Pan American Health Organization

About the Mount Sinai Health System

Mount Sinai Health System is one of the nation's leading integrated academic health systems and one of the largest in the New York metropolitan area. Its comprehensive system includes seven hospitals, more than 400 outpatient practices, over 600 research and clinical laboratories, the Icahn School of Medicine at Mount Sinai, the Graduate School of Biomedical Sciences, and the Mount Sinai Phillips School of Nursing. Together, the Health System comprises approximately 48,000 employees, more than 9,000 physicians, and 8,600 nurses.

As a leading learning health system, Mount Sinai combines clinical expertise with scientific discovery to improve patient care while training the next generation of health care and biomedical leaders. The Health System provides care across every stage of life, from prenatal care through geriatrics, while advancing personalized medicine through artificial intelligence, data science, and biomedical research.

Mount Sinai is consistently recognized among the nation's leading academic health systems for patient care, research, and education. The Mount Sinai Hospital is ranked No. 1 in New York by Newsweek and No. 5 on the magazine's World's Best Hospitals list. The Icahn School of Medicine at Mount Sinai ranks No. 11 among U.S. medical schools and No. 1 among freestanding medical schools for National Institutes of Health funding, reflecting the strength of its scientific enterprise and leadership in biomedical research.