The Public Health Response to Hantavirus: Key Actions, Perspectives, and Takeaways

May 15, 2026 | Ericka McGowan, Sidnie Christian, Margaret Nilz

Decorative. On May 2, the World Health Organization (WHO) received notification of an international hantavirus cluster linked to passengers aboard the MV Hondius cruise ship, following reports of severe acute respiratory illness. Subsequent laboratory testing confirmed infection with the Andes strain of hantavirus, a rare zoonotic virus associated with hantavirus pulmonary syndrome.

The event drew international public health attention because of the distinct challenges posed by the cruise ship setting, the need for multi-country coordination as exposed passengers returned home, and the involvement of the Andes virus — which can be transmitted person to person unlike other strains of hantavirus. In response, WHO and U.S. health authorities initiated contact tracing and surveillance to monitor for additional cases.

Despite international attention, the risk to the public is low at this time. However, it remains crucial for state and territorial health officials to stay up to date on this developing threat, which serves as an important reminder that public health preparedness is more critical than ever.

What Is Hantavirus?

Hantaviruses belong to the family Hantaviridae within the order Bunyavirales and are primarily spread through contact with infected rodents (i.e., via exposure to their urine, droppings, saliva, or contaminated surfaces). Various strains exist globally, including the Sin Nombre virus, predominant in North America, and the Andes virus, predominant in South America. In humans, clinical signs are non-specific, including fever, fatigue, muscle aches, headache, and gastrointestinal symptoms. In severe cases, infection may progress to hantavirus pulmonary syndrome, with rapid onset of cough, shortness of breath, and fluid accumulation in the lungs.

The recent cases raised concerns as the cruise ship setting likely facilitated exposure among passengers and crew. Additionally, the expedition's international nature meant potential exposure across multiple countries, with passengers disembarking before confirmation that illnesses on board were due to Andes virus — thus requiring coordinated surveillance, contact tracing, and risk communication among national health agencies. The particularly long incubation period of the Andes virus, 4-42 days after exposure, further complicates monitoring.

MV Hondius Hantavirus Outbreak: Key Insights

Timeline

In early April, the MV Hondius ship departed Argentina.
On April 11, the first case died on board, and a close contact died shortly after.
On April 28, a passenger experienced onset of symptoms, later presenting with pneumonia, and died on May 2.
On May 2, the United Kingdom reported a cluster of passengers with severe respiratory illness to WHO. At the time of reporting, 147 passengers and crew were on board while 34 passengers had disembarked.
On May 2, PCR testing confirmed hantavirus infection of a probable case.
On May 10, the MV Hondius was permitted to dock and let passengers disembark in the Canary Islands off the coast of Spain. Passengers were then transported to their home countries via non-commercial means.
On May 11, U.S. passengers arrived at the National Quarantine Unit (NQU) in Nebraska for evaluation and monitoring.
WHO and CDC continue to provide updates as the situation evolves.

Risk to the Public

While the risk to the public remains low, it is important for public health authorities to assess and monitor contacts closely during the 42-day period for symptoms, as deterioration can occur quickly. Monitoring and assessment are collaborative efforts supported by CDC and led by state and local health departments. CDC released interim risk assessment guidance to support health departments in managing people with potential exposure related to the MV Hondius. It provides definitions of high- and low-risk contacts, recommended care, monitoring, and guidance to reduce the risk of transmission and exposure.

A Coordinated Public Health Response

This outbreak punctuates the importance of international and federal agencies, state and local health departments, laboratories, health care systems, and specialized treatment centers working together to manage emerging threats. Shared guidance and regulations were necessary to help standardize monitoring and response efforts.

WHO coordinated with 10 countries to ensure timely information sharing, response, repatriation, and contact tracing. Domestically, the U.S. Department of State, Health and Human Services Administration of Strategic Preparedness and Response (ASPR), and CDC coordinated to form the domestic hantavirus taskforce. Together, the agencies have managed:

U.S. passenger transport and repatriation.
International coordination and communications.
Access to health care and treatment structure.
Quarantine and preparedness assets.
Disease surveillance.
Epidemiologic support.
Risk assessment.
Public communication.
Coordination with state and local public health departments.

This response highlights the expertise, logistics, and coordination required to manage high-consequence public health threats.

Specialized Response Systems

Responses to high-consequence infectious diseases (HCID) often require specialized infrastructure beyond routine health care. During events like this Hantavirus cluster, quarantine facilities, treatment centers, and coordinated health care networks help safely manage potentially exposed travelers while supporting health care system readiness. Together, these specialized preparedness systems help ensure that patients can be safely evaluated and treated while minimizing disruption to broader health care operations during HCID emergencies:

The NQU at the University of Nebraska Medical Center and the Global Center for Health Security is a key component of this infrastructure. This unit is specifically designed to support quarantine and individuals exposed to HCIDs. U.S. passengers returning from the cruise ship were transported to Nebraska for assessment and monitoring, including one asymptomatic passenger who was admitted to the Medical Center’s Biocontainment Unit for further evaluation but has since been cleared to return back to the NQU.
Regional Emerging Special Pathogen Treatment Centers (RESPTCs) serve as specialized hubs within the National Special Pathogen System. ASPR funds 13 RESPTCs in the United States to support management of care related to high consequence pathogens. The system is designed to distribute specialized care, offset operational burden, and maintain national surge capacity during complex infectious disease responses.
ASPR’s Hospital Preparedness Program provided additional preparedness aid. This program supports health care coalitions and strengthens coordination among hospitals, emergency management agencies, public health departments, and health care partners. By advancing planning, training, exercises, and regional coordination, it helps health care systems maintain surge capacity and preparedness for complex emergencies.
The Laboratory Response Network, which supports responses to biological threats, emerging infectious diseases, and other public health emergencies, plays a role in public health responses by supporting epidemiologic investigations and providing timely laboratory information to guide monitoring and response activities. In response to this Hantavirus cluster, the Association of Public Health Laboratories activated its Incident Command System to help support a coordinated laboratory response to the Andes virus.

The Role of State and Local Health Departments

State, territorial, and local public health agencies play a central role in infectious disease responses, especially when exposed travelers cross jurisdictional boundaries. For this response, agencies coordinated contact tracing, symptom monitoring, health care communication and preparation, laboratory coordination, and public risk communication.

State and Territorial

State and territorial health agencies serve as the primary lead for investigating and managing public health emergencies within their jurisdictions. In addition to coordinating with federal partners, health care systems, and laboratories, state and territorial health agencies may exercise legal authorities (i.e., isolation and quarantine) when necessary to help contain infectious disease threats. Their role helps translate national guidance into coordinated, jurisdiction-specific response activities.

Local

Local health departments also play a multifaceted role in outbreak response through community-level coordination, health care access, communication, and follow-up for potentially exposed individuals. In some states, local health departments also have the authority related to quarantine and isolation to prevent spread of public health threats. Local health departments help connect public health agencies, health care, emergency management partners, and community organizations to facilitate operational coordination and timely information sharing.

Support from the Public Health Emergency Preparedness Cooperative Agreement

Many of these preparedness and response capabilities are supported by the Public Health Emergency Preparedness cooperative agreement, which has helped health departments across the country strengthen their ability to respond to infectious disease outbreaks, natural disasters, and other public health emergencies since 2002. It supports surveillance capacity, emergency coordination, epidemiology staffing, and risk communication capabilities while helping jurisdictions build flexible and adaptable preparedness systems before emergencies occur. Events like this recent Hantavirus cluster demonstrate how preparedness investments made before emergencies occur help jurisdictions respond more quickly, cohesively, and effectively to rare emerging infectious disease threats.

Key Public Health Takeaways

Detection

The nonspecific nature of early infectious disease symptoms can make outbreak recognition challenging, especially when emerging diseases are involved. Rapid detection, laboratory confirmation, and coordinated surveillance systems are essential for early recognition.

Response

Modern travel can accelerate the spread and complexity of infectious disease events due to close-contact exposures and the rapid movement of individuals. As such, an effective response relies on coordination among local, national, and global agencies — to best support timely contact tracing, surveillance, and consistent messaging amid the evolving threat.

Ultimately, robust surveillance systems, laboratory capacity, and coordinated public health infrastructure are essential to managing outbreaks effectively.

Supplemental Resources

Centers for Disease Control and Prevention

World Health Organization

Other

Hantavirus Aboard the MV Hondius by The Pandemic Center Outbreak Observatory
Andes Virus Makes Its Way to US: What We Know — and How Public Health Laboratories Are Responding by The Association of Public Health Laboratories
ASPR’s Response to the 2026 Hantavirus Outbreak by ASPR

Reviewed by Susan Kansagra, MD, MBA, Chief Medical Officer and Meredith Allen, DrPH, MS, Vice President, Health Security.