Disease Outbreak News

Hantavirus cluster linked to cruise ship travel, Multi-country

4 May 2026

Situation at a glance

On 2 May 2026, a cluster of passengers with severe respiratory illness aboard a cruise ship was reported to the World Health Organization. The ship is carrying 147 passengers and crew. As of 4 May 2026, seven cases (two laboratory confirmed cases of hantavirus and five suspected cases) have been identified, including three deaths, one critically ill patient and three individuals reporting mild symptoms. Illness onset occurred between 6 and 28 April 2026 and was characterized by fever, gastrointestinal symptoms, rapid progression to pneumonia, acute respiratory distress syndrome and shock. Further investigations are ongoing. The outbreak is being managed through coordinated international response, and includes in-depth investigations, case isolation and care, medical evacuation and laboratory investigations. Human hantavirus infection is primarily acquired through contact with the urine, faeces, or saliva of infected rodents. It is a rare but severe disease that can be deadly. Although uncommon, limited human to human transmission has been reported in previous outbreaks of Andes virus (a specific species of hantavirus). WHO currently assesses the risk to the global population from this event as low and will continue to monitor the epidemiological situation and update the risk assessment.

Description of the situation

On 2 May 2026, WHO received notification from the National International Health Regulations (2005) (IHR) Focal Point of the United Kingdom of Great Britain and Northern Ireland (hereafter referred to as the United Kingdom) regarding a cluster of severe acute respiratory illness, including two deaths and one critically ill passenger, aboard a Dutch-flagged cruise ship. On 2 May 2026, laboratory testing conducted in South Africa confirmed hantavirus infection in one patient who is critically ill and in intensive care. On 3 May, one additional death was reported. A further three suspected cases remain on board. As of 4 May, a total of seven (two confirmed and five suspected) cases, including three deaths, have been reported.

The vessel departed Ushuaia, Argentina, on 1 April 2026 and followed an itinerary across the South Atlantic, with multiple stops in remote and ecologically diverse regions, including mainland Antarctica, South Georgia, Nightingale Island, Tristan da Cunha, Saint Helena, and Ascension Island. The extent of passenger contact with local wildlife during the voyage, or prior to boarding in Ushuaia remains undetermined. The vessel carries a total of 147 individuals, including 88 passengers and 59 crew members. Onboard passengers and crew represent 23 nationalities.  As of 4 May 2026, the vessel is moored off the coast of Cabo Verde.

Summary of cases:

Case 1: An adult male developed symptoms of fever, headache, and mild diarrhoea on 6 April 2026 while on board the ship. By 11 April, the case developed respiratory distress and died on board on the same day. No microbiological tests were performed. The body of the passenger was removed from the vessel to Saint Helena (a British Overseas Territory) on 24 April.

Case 2: An adult female, who was a close contact of case 1, went ashore at Saint Helena on 24 April 2026 with gastrointestinal symptoms. She subsequently deteriorated during a flight to Johannesburg, South Africa, on 25 April. She later died upon arrival at the emergency department on 26 April. On 4 May, the case was subsequently confirmed by PCR with hantavirus infection. Contact tracing for passengers on the flight has been initiated.

Cases 1 and 2, had travelled in South America, including Argentina, before they boarded the cruise ship on 1 April 2026.

Case 3: An adult male presented to the ship's doctor on 24 April 2026 with febrile illness, shortness of breath and signs of pneumonia. On 26 April, his condition worsened. He was medically evacuated from Ascension to South Africa on 27 April, where he is currently hospitalised in an Intensive Care Unit (ICU). Laboratory testing on an extensive respiratory pathogen panel was negative; however, polymerase chain reaction (PCR) testing confirmed hantavirus infection on 2 May 2026. Serology, sequencing and metagenomics are ongoing.

Case 4: An adult female, with presentation of pneumonia, died on 2 May 2026. The onset of symptoms was on 28 April, with fever and a general feeling of being unwell.

Three suspected cases have reported high fever and/or gastrointestinal symptoms and remain on board. Medical teams in Cabo Verde are evaluating the patients and collecting additional specimens for testing.

Public health response

Authorities from States Parties involved in the management of the event to date – Cabo Verde, the Netherlands, Spain, South Africa and the United Kingdom - have initiated coordinated response measures including:

  • Ongoing engagement between WHO and the National IHR Focal Points of Cabo Verde, the Netherlands, South Africa, Spain and the United Kingdom, to ensure timely information sharing and coordination of response actions.
  • WHO shared information about the events with National IHR Focal Points globally.
  • Passengers onboard have been advised to practice maximal physical distancing and remain in their cabins where possible.
  • Epidemiological investigations are underway to determine the source of exposure.
  • The National IHR Focal Point of Argentina shared the passenger and crew lists with the National IHR Focal Points of the respective countries, according to each person’s nationality.
  •  In line with the Working Arrangement between the WHO Emergency Medical Team (EMT) Secretariat and the EU Emergency Response Coordination Centre (ERCC), the EMT Secretariat has launched formal discussions to support the clinical management and medical evacuation of symptomatic passengers.
  • Logistic support has been provided, including sample collection items.
  • Laboratory testing and confirmation of hantavirus infection have been conducted at the National Institute for Communicable Diseases (NICD) of South Africa. Serology, sequencing and metagenomics are ongoing.
  • Additional laboratory samples from symptomatic passengers are being sent, with WHO support, to the Institut Pasteur de Dakar, Senegal, for testing.
  • WHO has activated three-level coordination and is supporting national authorities in implementing risk-based, evidence-informed public health measures in accordance with the provisions of the IHR and related WHO technical guidance documents.

WHO risk assessment

Hantavirus cardiopulmonary syndrome (HCPS), also known as hantavirus pulmonary syndrome (HPS), is a zoonotic, viral respiratory disease caused by hantaviruses of the genus Orthohantavirus, family Hantaviridae, order Bunyavirales. More than 20 viral species have been identified within this genus. In the Americas, Sin Nombre virus is the predominant cause of HPS in North America, while Orthohantavirus andesense is responsible for most cases in South America.

Human Hantavirus infection is primarily acquired through contact with the urine, faeces, or saliva of infected rodents or by touching contaminated surfaces. Exposure typically occurs during activities such as cleaning buildings with rodent infestations, though it may also occur during routine activities in heavily infested areas. Human cases are most commonly reported in rural settings, such as forests, fields, and farms, where rodents are present, and opportunities for exposure are greater. HPS is characterized by headache, dizziness, chills, fever, myalgia, and gastrointestinal problems, such as nausea, vomiting, diarrhoea, and abdominal pain, followed by sudden onset of respiratory distress and hypotension. Symptoms of HPS typically occur from 2-4 weeks after initial exposure to the virus. However, symptoms may appear as early as one week and as late as eight weeks following exposure.

Hantavirus infections are relatively uncommon globally.  In 2025 (as of epidemiological week 47), in the Region of the Americas, eight countries reported 229 cases and 59 deaths with a CFR of 25.7%. [1] In the European Region, 1885 hantavirus infection reported in 2023 (0.4 per 100,000), marking the lowest rate observed between 2019 and 2023.[2] In East Asia, particularly China and the Republic of Korea, Hantavirus haemorrhagic fever with renal syndrome (HFRS) continues to account for many thousands of cases annually, although incidence has declined in recent decades.

Hantavirus infections are associated with a case fatality rate of <1–15% in Asia and Europe and up to 50% in the Americas. While there are no specific treatment nor vaccines for hantavirus infections, early supportive care and immediate referral to a facility with a complete ICU can improve survival.

Environmental and ecological factors affecting rodent populations can influence disease trends seasonally. Since hantavirus reservoirs are sylvatic rodents, transmission can occur when people come into contact with rodent habitats.

Although uncommon, limited human‑to‑human transmission of HPS due to Andes virus has been reported in community settings involving close and prolonged contact. Secondary infections among healthcare workers have been previously documented in healthcare facilities, though remain rare.

WHO currently assesses the risk to the global population from this event as low and will continue to monitor the epidemiological situation and update the risk assessment as more information becomes available.

WHO advice

WHO advises that States Parties involved in this event continue efforts in detection, investigation, reporting, case management, infection control, and public health management on board, including ship sanitation measures, in close coordination with the conveyance operator, to prevent and control infections caused by hantaviruses.

In the context of the current outbreak, passengers and crew members should practice frequent hand hygiene, remain vigilant of Hantavirus symptoms and undertake active symptom monitoring for 45 days.  Crew must ensure adequate environmental cleaning (avoiding dry sweeping) and ventilation in the ship. Passengers and crew members experiencing symptoms should inform medical professionals on board and self-isolate. If respiratory symptoms are present to practice respiratory etiquette and wear a medical mask.

Vigilance among travellers, crew, including those involved in implementing ship sanitation measures, or other personnel returning from areas where hantavirus is known to be present, as well as on conveyances engaged in eco-tourism on a journey from and through those areas, is essential.

Early recognition of suspected cases, prompt isolation, and consistent adherence to recommended infection prevention and control measures remain essential to protect healthcare personnel.

Diagnosis of HPS is with serologic testing for IgM or rising titres of IgG antibodies using enzyme-linked immunoassay (ELISA) or with reverse transcriptase polymerase chain reaction (RT–PCR) to detect viral RNA.

In healthcare environments, standard precautions* should be applied for all patients, including hand hygiene, environmental cleaning and safe handling of blood and body fluids. In addition to standard precautions, transmission-based precautions should be implemented for management of suspect or confirmed cases. Standard precautions combined with transmission-based precautions during close contact are considered sufficient. For aerosol-generating procedures, airborne precautions should be used. [3]

When HPS is suspected, patients should be promptly transferred to an emergency department or intensive care unit for close monitoring and supportive management.

Initial management should include supportive care with antipyretics and analgesics as needed. For confirmed hantavirus, antibiotics are not routinely indicated. However, before a definitive diagnosis is established (and bacterial infection is a diagnostic possibility), or if superadded bacterial infection is suspected, empiric broad-spectrum antibiotics may be appropriate. Clinical management relies primarily on careful fluid administration, hemodynamic monitoring, and respiratory support. Given the rapid progression of HCPS, close monitoring and early transfer to ICU are critical for more severe cases. Mechanical ventilation, meticulous volume control, and vasopressors may be required. For severe cardiopulmonary insufficiency, extracorporeal mechanical oxygenation may be lifesaving. In severe cases of renal dysfunction, dialysis may be required.

Although ribavirin has shown efficacy against hantavirus haemorrhagic fever with renal syndrome, it has not demonstrated effectiveness for HCPS and is not licensed for either treatment or prophylaxis of hantavirus pulmonary syndrome. At present, there is no specific antiviral treatment approved for HCPS.

Public health awareness efforts should focus on improving early detection, ensuring timely treatment, and reducing exposure risks. Preventive measures should address occupational and ecotourism-related exposures, emphasize standard and transmission-based infection prevention and control practices, and include rodent control strategies. Most routine tourism activities carry little or no risk of exposure to rodents or their excreta.

The potential for human-to-human transmission should be considered in areas where Andes and potentially other South American hantaviruses are endemic.

Individuals engaging in outdoor activities where endemic transmission is known, such as visiting rural areas, camping or hiking, should take precautions to minimise potential exposure to infectious materials.

Risk communication and community engagement interventions should prioritize transparent, timely, and culturally appropriate communication to raise awareness of hantavirus transmission risks—particularly exposure to rodent excreta in endemic areas—and promote practical preventive behaviours such as safe food storage, avoiding contact with rodents, wet-cleaning methods (no dry sweeping), and proper ventilation. Community engagement strategies should involve local leaders and workers in high-risk occupations to co-develop and disseminate tailored messages, address misinformation, and reinforce early care seeking.

Surveillance for HPS should be integrated into a comprehensive national surveillance system and include clinical, laboratory, and environmental components. The implementation of integrated environmental management strategies aimed at reducing rodent populations is also recommended.

*Standard precautions refer to a set of practices that are applied to the care of patients, regardless of the state of infection (suspicion or confirmation), in any place where health services are provided. These practices aim to protect both healthcare professionals and patients and include hand hygiene, use of personal protective equipment, respiratory hygiene and cough etiquette, safe handling of sharps materials, safe injection practices, use of sterile instruments and equipment and cleaning of hospital environments and the environment. Adapted from “Standard precautions for the prevention and control of infections: aide-memoire”- WHO, 2022.  Available at https://www.who.int/publications/i/item/WHO-UHL-IHS-IPC-2022.1  

WHO advises against the application of any travel or trade restrictions based on the current information available on this event. 

Further information


[1] Pan American Health Organization / World Health Organization (PAHO/WHO). Epidemiological Alert Hantavirus Pulmonary Syndrome (HPS). https://www.paho.org/en/documents/epidemiological-alert-hantavirus-pulmonary-syndrome-americas-region-19-december-2025 

[2] Hantavirus infection - Annual Epidemiological Report for 2023. https://www.ecdc.europa.eu/en/publications-data/hantavirus-infection-annual-epidemiological-report-2023

[3] Standard precautions for the prevention and control of infections: aide-memoire. https://www.who.int/publications/i/item/WHO-UHL-IHS-IPC-2022.1 

 

Citable reference: World Health Organization (4 May 2026). Disease Outbreak News. Hantavirus cluster linked to cruise ship travel- Multi-country. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON599

Corrigendum: The Disease Outbreak News was updated on 5 May 2026 to include an additional statement to enhance clarity on infection prevention and control (IPC) measures.