Situation at a glance
-- This is the third Disease Outbreak News report on the hantavirus cluster, following the notification to the World Health Organization (WHO) on 2 May 2026 of severe respiratory illness cases aboard MV Hondius, a cruise ship.
-- Since the last DON was published on 8 May, two additional confirmed cases were reported from France and Spain.
-- In addition, there is one inconclusive result for a case in the United States of America.
-- All were passengers on the ship.
-- As of 13 May, a total of 11 cases, including three deaths, have been reported (case fatality ratio 27%).
-- Eight cases were laboratory-confirmed for Andes virus (ANDV) infection, two are probable, and one case remains inconclusive and undergoing further testing.
-- Through the International Health Regulations (2005) (IHR) channels, National IHR Focal Points (NFPs) have all been informed and are supporting international contact tracing efforts.
-- WHO has assessed the risk posed by this event to the global population as low and will continue to monitor the epidemiological situation and update the risk assessment as needed.
Description of the situation
-- On 2 May 2026, WHO received notification from the IHR NFP 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 the Dutch-flagged cruise ship MV Hondius.
-- As of 13 May, a total of 11 cases (eight confirmed, one inconclusive and two probable cases), including three deaths (two confirmed and one probable), have been reported.
-- Since the last Disease Outbreak News was published on 8 May, two additional confirmed cases and one inconclusive case have been reported among passengers.
-- These are one confirmed case from France, who became symptomatic during repatriation, one confirmed case from Spain, tested upon arrival following repatriation but currently well and asymptomatic, and one case considered inconclusive.
-- The latter was repatriated to the United States of America, is currently asymptomatic with inconclusive laboratory results (one positive and one negative result from two different laboratories), and is being retested.
-- The individual was sampled due to high-risk exposure to confirmed cases on board.
-- All laboratory-confirmed cases are confirmed for ANDV infection.
-- All were passengers onboard the MV Hondius.
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Figure 1. Epidemiological curve of Andes hantavirus cases (n = 11) reported to WHO as of 13 May 2026, 17:00.
{Click on Image ot Enlarge}
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-- Based on currently available information, the working hypothesis is that the first case acquired the infection prior to boarding the cruise, through exposure on land.
-- Investigations are ongoing to elucidate the potential circumstances of exposure and the source of the outbreak, in collaboration with authorities in Argentina and Chile.
-- Current evidence suggests subsequent human-to-human transmission onboard the ship.
-- This is also supported by a preliminary analysis of the sequences, which show a close, near-identical sequenced from different cases.[1]
-- The outbreak is being managed through a coordinated international response, including:
° in-depth epidemiological investigations,
° case isolation and clinical management,
° medical evacuations,
° laboratory testing and international contact tracing,
° quarantining and monitoring.
-- Recommendations may be updated as additional epidemiological and laboratory evidence, including genetic sequencing data, becomes available.
-- Follow-up and contact tracing for all contacts of hantavirus cases linked to the cruise ship is ongoing.
-- This includes passengers who disembarked in Saint Helena, United Kingdom, on 24 April; Praia, Cabo Verde, on 6 May; and Tenerife, Spain, on 10 and 11 May.
-- Passengers who travelled on flights who may have had exposure to subsequently confirmed cases have been identified and contacted.
-- Contacts are being monitored by local health authorities in their respective countries.
-- On 10 May, the ship arrived in the Canary Islands, Spain, where disembarkation began.
-- Passengers and most of the crew were repatriated from the Canary Islands to their respective residence countries or transit points via specially arranged non-commercial flights, with WHO and partners supporting the disembarkation process.
-- The ship left the Canary Islands on 11 May and is sailing to the Netherlands, with 25 crew members remaining on board, along with two Dutch health and care workers to conduct their health monitoring and provide any healthcare that may be necessary.
Epidemiology
-- 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.
-- Hantaviruses are associated with two major distinct clinical syndromes in humans: HPS predominantly reported in the Americas, and hemorrhagic fever with renal syndrome (HFRS), mainly reported in Europe and Asia.
-- However, human-to-human transmission has only been reported for HPS associated with Andes virus infection.
-- Andes virus is endemic in South America, with confirmed circulation and human cases reported primarily in Argentina and Chile, and additional cases and related strains identified in Uruguay, southern Brazil, and Paraguay.
-- 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 symptoms, such as nausea, vomiting, diarrhoea, and abdominal pain, followed by sudden onset of respiratory distress and hypotension. Symptoms of HPS typically occur from 1-6 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, in the Region of the Americas, eight countries reported HPS, 229 cases and 59 deaths with a CFR of 25.7%.[2]
-- HPS is not reported in other parts of the world.
-- In the European Region, 1885 hantavirus infections causing HFRS were reported in 2023 (0.4 per 100 000), marking the lowest rate observed between 2019 and 2023.[3]
-- In East Asia, particularly China and the Republic of Korea, HFRS continues to record thousands of cases annually, although incidence has declined in recent decades.
-- The overall CFR for HPS can be as high as 50%. While there are no licensed 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.
-- Secondary transmission appears most likely during the early phase of illness, when the virus is more transmissible.
-- Currently, little evidence is available due to the scarcity of hantavirus outbreak related to human-to-human transmission.
Public health response
-- Authorities from States Parties managing cases and/or contacts, WHO, and partners have initiated coordinated response measures, including:
° Ongoing engagement between WHO and the NFPs of countries managing cases and/or contacts to ensure timely information sharing and coordination of response actions.
° International contact tracing is ongoing.
° WHO is requesting regular information sharing and periodic updates from States Parties through IHR channels regarding contact monitoring and the health status of high-risk contacts
° Crew members still onboard, to take the MV Hondius to the Netherlands, have been advised to practice physical distancing and remain in their cabins where possible, while on the cruise ship.
° Experts from WHO and the European Centre for Disease Prevention and Control (ECDC) were deployed on board the ship to support epidemiological investigation and provide public health advice before disembarkation in the Canary Islands, Spain.
° Two Dutch medical doctors boarded the ship in Cabo Verde to conduct health monitoring and provide any health care that may be necessary. One disembarked in Tenerife, while a Dutch nurse boarded, to assist in monitoring and providing any healthcare to the remaining crew members on board.
° WHO Director-General Dr Tedros Adhanom Ghebreyesus travelled to the Canary Islands on 9 May, along with other experts from WHO, to meet with the national authorities, including ministers, and support the coordination of the operations. He met with the Prime Minister of Spain on 12 May.[4]
° Epidemiological investigations continue to better define epidemiological links between cases and exposure factors on the ship, as well as to try to understand the potential source of exposure
-- WHO has developed and published specific technical guidance documents to support response to the event, including:
° Technical guidance on the management of hantavirus on board the ship;
° Technical note for the disembarkation and onward management of passengers and crew in the context of an Andes-virus-associated cluster;
° Management of contacts of Andes Virus (ANDV) cases from the MV Hondius cruise ship
-- NFPs of affected countries have been in contact about passenger and crew information through established IHR channels for those on the ship, as well as on planes where a known case was on board.
-- The NFP of Argentina aided in the reconstruction of the travel itinerary of the first two cases in the Southern Cone subregion of the Americas and assess any potential exposure to hantavirus. They also shared the National Hantavirus Epidemiological Circular: Update epidemiological Surveillance and Management Standards on Hantavirus.
-- WHO supported collaboration across relevant laboratories with prior experience to ensure timely testing, with further analyses ongoing, including serology, molecular diagnostics, sequencing, and metagenomics.
-- Risk communication coordination and support are being provided to ensure sharing of regular, timely and evidence-based information. 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 regularly convenes expert calls across laboratory, clinical management, epidemiology, and Infection prevention and control (IPC) domains to facilitate timely experience sharing and coordinated expert support.
-- WHO supported the streamlining and development of research protocols on the natural clinical history in collaboration with national partner institutions and planned a hantavirus scientific consultation on medical countermeasures.
WHO risk assessment
-- WHO currently assesses the public health risk for those who were onboard the cruise ship as moderate, and at the Global level as low for the following reasons:
° Andes virus has demonstrated limited human-to-human transmission in previous outbreaks, typically occurring among close contacts and within household settings, generally requiring prolonged close exposure. Transmission can be contained through early detection, isolation of cases, clinical management, and contact management. However, the ship environment presented an increased risk due to close living quarters, shared indoor spaces, prolonged exposure, and frequent interpersonal interactions, all of which likely facilitated transmission.
° The HCPS with hantaviruses in the Americas, including Andes can have a high case fatality ratio, reaching 40-50%, particularly among elderly individuals and those with co-morbidities. The average age of passengers on board the ship was 65 years old.
° Investigations on the travel history and potential exposures of the first case in the Southern Cone subregion of the Americas are ongoing and suggest possible exposure to rodents during bird watching activities. Viral sequencing analyses are also ongoing and will compare the ANDV strain associated with this outbreak with strains circulating in Argentina and Chile, where the disease is enzootic. The preliminary sequencing analysis for the cases indicates a high degree of genetic similarity—showing no more than one single nucleotide polymorphisms (SNP) difference per individual—strongly indicates that the outbreak likely arose from a single zoonotic spillover event, or from a very small number of closely related spillover events.[1]
° Additional cases may occur among individuals exposed before implementation of containment measures. However, the current response, including quarantine for those who have left the ship and rapid isolation of any new suspect cases and the monitoring of contacts, is expected to limit the risk of further spread.
° As there is no specific antiviral treatment for HPS, suspected cases require prompt transfer to an adequately equipped emergency department or intensive care unit, where available, for close monitoring and supportive management to improve chances of recovery. Consequently, for remote areas, rapid transfer to a mainland healthcare facility is required, which may be challenging under the current conditions.
° For the general public, including people not exposed on board the ship or through close contact with a confirmed case, the overall probability of infection remains low. Current evidence indicates that transmission occurs through close and prolonged contact, and can be effectively limited through early detection, isolation of cases, and contact tracing.
-- More detailed epidemiological, clinical and laboratory investigations are required to inform further iterations of this risk assessment.
WHO advice
-- WHO advises that States Parties involved in this event continue public health coordination and management efforts related to the ship and relevant flights, and in countries where cases and/or contacts are present or will be returning to.
-- Based on information available and ongoing epidemiological, clinical and environmental investigations, and applying the precautionary principle, this includes:
° contact tracing and monitoring,
° detection, investigation, reporting of suspected cases,
° laboratory testing of suspected cases,
° case management,
° infection prevention and control measures, and
° clear and transparent communication to affected individuals and the general public.
-- Outside the context of the ship, high-risk contacts may include intimate partners, household members and persons with prolonged close indoor exposure, healthcare workers with unprotected exposure, and individuals handling contaminated materials or body fluids without appropriate personal protective equipment, outlined in the interim guidance published on 8 May.
-- Given that infectiousness peaks in the early phase of illness, and that pre-symptomatic transmission cannot be entirely ruled out, as a precautionary principle, WHO recommends active monitoring and home or facility quarantine of high-risk contacts for 42 days following last exposure.
-- Current evidence does not support routine laboratory testing of contacts for outbreak control nor the quarantine of low-risk contacts; low-risk contacts should undertake passive self-monitoring and seek medical evaluation if symptoms occur. Recommendations are dynamic and will be adapted as more evidence emerges.
-- Contact investigations should use available information sources, including interviews, passenger manifests, seating arrangements and activity logs, to improve completeness of contact identification.
-- Early recognition of suspected cases, prompt isolation, and consistent adherence to recommended infection prevention and control measures remain essential to protect healthcare personnel, other passengers and crew members.
-- In healthcare settings:
° Apply standard precautions* at all times for all patients, including hand hygiene, environmental cleaning, and waste management.
° Isolate any suspected or confirmed case in a single, well‑ventilated room with doors closed.
° Implement transmission‑based precautions in addition to standard precautions for suspected or confirmed cases.
° Ensure health and care workers wear appropriate personal protective equipment (respirators, eye protection, gowns, and gloves).
° Perform hand hygiene before and after the use of personal protective equipment.
° Manage waste generated from suspected or confirmed cases as infectious waste.
° Apply airborne precautions during aerosol‑generating procedures.
-- 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 secondary 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 HPS, close monitoring and early transfer to ICU are critical for more severe cases.
-- Mechanical ventilation, judicious fluid management, and vasopressors may be required.
-- For severe cardiopulmonary insufficiency, extracorporeal membrane oxygenation may be lifesaving.[5] 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 HPS and is not licensed for either treatment or prophylaxis of hantavirus pulmonary syndrome.
-- At present, there is no specific antiviral treatment approved for HPS; a number of existing drugs have antiviral activity in laboratory studies but not yet demonstrated in human disease.
-- 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 infection prevention and control measures, and include rodent control strategies. Most routine tourism activities carry little or no risk of exposure to rodents or their excreta.
-- Risk communication and community engagement (RCCE) interventions should prioritize transparent, timely, and culturally appropriate communication to raise awareness of hantavirus transmission risks.
-- RCCE strategies should support coordinated, timely and aligned evidence-based information to ensure concerned people receive clear, consistent and actionable information, including explanations of the public health measures being implemented.
-- RCCE activities should explicitly address public concerns regarding transmissibility, severity, and international travel, and clarify what actions are and are not necessary for different population groups.
-- Operational measures should integrate RCCE activities throughout all phases of the event. The implementation of integrated environmental management strategies aimed at reducing rodent populations is also recommended.
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-- At this time, WHO does not recommend any changes to routine activities for the general public.
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-- People who were on board the affected ship, or who have had close contact with a confirmed case, should follow the specific monitoring and public health advice outlined above. Guidance may be updated as further evidence becomes available.
-- Based on the current information available on this event, WHO advises against the application of any travel or trade restrictions beyond the restriction of movement of identified high-risk contacts.
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{*} 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
Further information
1) World Health Organization. Management of contacts of Andes virus (ANDV) cases from the MV Hondius cruise ship. https://www.who.int/publications/m/item/management-of-contacts-of-andes-virus-(andv)-cases-fromthe-mv-hondius-cruise-ship
2) World Health Organization. WHO Technical note for the disembarkation and onward management of passengers and crew in the context of an Andes virus-associated cluster MV Hondius cruise ship. https://www.who.int/publications/m/item/who-technical-note-for-the-disembarkation-and-onward-management-of-passengers-and-crew-in-the-context-of-an-andes-virus-associated-cluster-mv-hondius-cruise-ship
3) World Health Organization. Hantavirus fact sheet. https://www.who.int/news-room/fact-sheets/detail/hantavirus
4) World Health Organization.WHO’s response to hantavirus cases linked to a cruise ship. https://www.who.int/news/item/07-05-2026-who-s-response-to-hantavirus-cases-linked-to-a-cruise-ship
5) World Health Organization. Handbook for management of public health events on board ships https://www.who.int/publications/i/item/9789241549462
6) World Health Organization. Guide to Ship Sanitation, 3rd edition https://www.who.int/publications/i/item/9789241546690
7) Preliminary analysis of Orthohantavirus andesense virus sequences from a cruise-ship related cluster, May 2026. https://virological.org/t/preliminary-analysis-of-orthohantavirus-andesense-virus-sequences-from-a-cruise-ship-related-cluster-may-2026/1029
8) World Health Organization. Standard precautions for the prevention and control of infections: aide-memoire. https://www.who.int/publications/i/item/WHO-UHL-IHS-IPC-2022.1
9) World Health Organization. Transmission-based precautions for the prevention and control of infections: aide-memoire. https://www.who.int/publications/i/item/WHO-UHL-IHS-IPC-2022.2
10) World Health Organization. Hantavirus outbreak toolbox. https://www.who.int/emergencies/outbreak-toolkit/disease-outbreak-toolboxes/hantavirus-outbreak-toolbox
11) World Health Organization (8 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-DON600
12) 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
13) World Health Organization. A decision framework for effective, equitable and context-specific public health and social measures during public health emergencies: decision navigator: https://iris.who.int/server/api/core/bitstreams/ceaf4aa7-00c8-4681-9c35-965e231a3706/content
14) Pan American Health Organization / World Health Organization. PAHO supports the international response to hantavirus pulmonary syndrome cases linked to a cruise ship in the Atlantic. https://www.paho.org/en/news/7-5-2026-paho-supports-international-response-hantavirus-pulmonary-syndrome-cases-linked
15) Epidemiological Alert Hantavirus Pulmonary Syndrome (HPS). https://www.paho.org/en/documents/epidemiological-alert-hantavirus-pulmonary-syndrome-americas-region-19-december-2025
16) Hantavirus in the Americas: Guidelines for diagnosis, treatment, prevention and control. Available at: https://iris.paho.org/handle/10665.2/40176
17) Hantavirus Prevention, CDC: https://www.cdc.gov/hantavirus/prevention/?CDC_AAref_Val=https://www.cdc.gov/hantavirus/hps/prevention.html
18) Martínez Valeria, Paola N, et al.. (2020). “Super-Spreaders” and Person-to-Person Transmission of Andes Virus in Argentina. New England Journal of Medicine. 383. 2230-2241. 10.1056/NEJMoa2009040.
19) US CDC. How to Clean Up After Rodents: https://www.cdc.gov/healthy-pets/rodent-control/clean-up.html
20) Hantavirus, Washington State Department of Heath, https://doh.wa.gov/sites/default/files/2025-08/420-056-Guideline-Hantavirus.pdf
21) Hantavirus Infection, MDS Manual, professional version: https://www.msdmanuals.com/professional/infectious-diseases/arboviruses-arenaviridae-and-filoviridae/hantavirus-infection
22) Handbook for management of public health events on board ships. https://www.who.int/publications/i/item/9789241549462
23) Hantavirus pulmonary syndrome, https://www.mayoclinic.org/diseases-conditions/hantavirus-pulmonary-syndrome/symptoms-causes/syc-20351838
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[1] Preliminary analysis of Orthohantavirus andesense virus sequences from a cruise-ship related cluster, May 2026. https://virological.org/t/preliminary-analysis-of-orthohantavirus-andesense-virus-sequences-from-a-cruise-ship-related-cluster-may-2026/1029
[2] 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
[3] Hantavirus infection - Annual Epidemiological Report for 2023. https://www.ecdc.europa.eu/en/publications-data/hantavirus-infection-annual-epidemiological-report-2023
[4] WHO Director-General's opening remarks at the media briefing on hantavirus – 12 May 2026. https://www.who.int/news-room/speeches/item/who-director-general-s-opening-remarks-at-the-media-briefing-on-hantavirus---12-may-2026
[5] Dietl CA, Wernly JA, Pett SB, et al. Extracorporeal membrane oxygenation support improves survival of patients with severe Hantavirus cardiopulmonary syndrome. The Journal of Thoracic and Cardiovascular Surgery. 2008;135(3):579-584. doi:10.1016/j.jtcvs.2007.11.020.
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Citable reference: World Health Organization (13 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-DON601
Source:
Link: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON601
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