Rapid #risk #assessment, acute event of potential public health concern: #Hantavirus #outbreak caused by #Andes virus (WHO, summary)

 

Risk statement

    -- This risk assessment provides an updated analysis of the current situation related to the hantavirus outbreak associated with the cruise ship MV Hondius. 

    -- The initial rapid risk assessment was issued on 5 May 2026 to the National International Health Regulations (IHR) Focal Points via the secure Event Information Site.

    -- The public health risk has been reassessed with the most current information available, and the global risk remains low. 

    -- The risk for passengers and crew who were onboard the cruise ship remains moderate, as individuals exposed prior to the implementation of control measures may still develop illness during the incubation period and should therefore be closely monitored. 

    -- This assessment takes into account that all the passengers have now disembarked and are under monitoring, although the ship continues with a reduced crew and a medical team to its home port. 

    -- It should also be noted that some passengers had disembarked in a limited number of other locations before the outbreak was identified and have likewise been placed under monitoring. 

    -- Additionally, identified passengers and crew members who travelled on associated flights are also under monitoring. 

    -- The assessment further considers identified risks, operational limitations, and the potential implications for ongoing public health response activities.

    -- Globally, hantavirus infections are considered a serious but generally low-incidence public health threat, primarily associated with environmental exposure to rodents and their excreta, with limited but important outbreak potential in specific geographic regions. 

    -- There are several variants of hantavirus, but Andes virus is the only hantavirus to have documented human-to-human transmission, which has been observed mainly in outbreaks in southern Argentina and Chile. 

    -- Hantavirus infection caused by Andes virus may cause hantavirus pulmonary syndrome (HPS; also called hantavirus cardiopulmonary syndrome, HCPS) and may lead to rapidly progressive severe respiratory distress and cardiogenic shock. 

    -- The case fatality rate (CFR) can reach up to 50%. 

    -- There is currently no approved antiviral treatment, and early clinical management remains primarily supportive.

    -- The current event is related to the notification on 2 May 2026, by the United Kingdom IHR National Focal Point to WHO of a cluster of severe acute respiratory illness cases aboard the Dutch-flagged cruise vessel MV Hondius. 

    -- The cluster initially included two deaths and one critically ill passenger, with the cause unknown at the time of notification. 

    -- On the same day, laboratory testing confirmed hantavirus infection in the critically ill passenger hospitalised in Johannesburg, South Africa. 

    -- Confirmation that the outbreak was caused by Andes virus was subsequently obtained on 5 May 2026 at the Geneva University Hospitals (HUG) laboratory in Geneva from a passenger that had disembarked earlier from the ship and returned to his home country with presentation of symptoms.

    -- The vessel departed from Ushuaia, Argentina on 1 April 2026, with 114 passengers and 61 crew, and followed an itinerary across the South Atlantic, including multiple stops in remote and ecologically diverse regions such as mainland Antarctica, South Georgia, Nightingale Island, Tristan da Cunha, Saint Helena, and Ascension Island. 

    -- During this period several passengers disembarked and embarked the ship at different stops, resulting in a total of 187 persons who were on the ship at some point during the journey. 

    -- From 11 April to 2 May, three passengers died. 

    -- On 3 May, MV Hondius moored off the coast of Cabo Verde where local health authorities visited the vessel to assess the condition of two remaining symptomatic individuals. These individuals and a high-risk contact were evacuated from the ship on 6 May, and the ship continued to the Canary Islands, Spain.

    -- The vessel arrived at the port of Granadilla, in Tenerife, Canary Islands, on 10 May, carrying 150 individuals, including 86 passengers, 60 crew members, and 4 health professionals from WHO, ECDC and the Netherlands. Passengers and crew represented 25 nationalities: Argentina, Australia, Belgium, Canada, the Democratic Republic of the Congo, France, Germany, Greece, Guatemala, India, Italy, Ireland, Japan, Montenegro, the Netherlands, New Zealand, Philippines, Poland, Portugal, the Russian Federation, Spain, Türkiye, Ukraine, the United Kingdom, and the United States. 

    -- Passengers and most of the crew disembarked on 10 and 11 May and were repatriated to their respective countries of residence 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 care workers to conduct their health monitoring and provide any healthcare that may be necessary.

    -- As of 15 May 2026, 10 cases (eight confirmed, and two probable cases), including three deaths (two confirmed and one probable), have been reported (CFR 30%). The contact from the United States of America that was previously reported as inconclusive has now been determined to be negative by serology.

    -- Of the eight laboratory-confirmed cases, three were genetically sequenced and identified as Andes virus. 

    -- Since the last RRA published on 5 May 2026, two additional confirmed cases (France=1, Spain=1) have been reported among the passengers. No secondary cases have been reported outside of the ship.

        • Epidemiological investigations traced the travel history of the first two cases, a couple who had spent approximately five months birdwatching across South America. This included visits to several areas where Oligoryzomys are known to occur and includes areas where Andes cases have been recorded in the past. Evidence suggests subsequent human-human transmission onboard the ship. This is also supported by a preliminary analysis of the sequences, which show a near-identical sequence from different cases.

        • Andes virus outbreaks that human-to-human transmission is limited, tends to remain clustered, and generally requires prolonged exposure. It can also be rapidly contained with control measures in place. However, infectious diseases pose an increased risk on cruise ships due to close living quarters, shared enclosed spaces, prolonged exposure, and frequent interpersonal contact, all of which can facilitate transmission. As a result, additional sporadic cases may still occur among previously exposed passengers and crew members.

        • While additional cases may still occur among passengers and crew members exposed before containment measures were implemented, the risk of onward transmission is expected to be reduced following disembarkation and the implementation of control measures, including rapid identification and isolation of suspected cases. There is no approved antiviral treatment for HPS; suspected cases require prompt medical evaluation, close monitoring, and supportive management, including intensive care where necessary.

    -- Consequently, the overall risk at the global level remains assessed as Low.

    -- The epidemiological situation will continue to be monitored, and the risk assessment will be updated as needed.

(...)

Source: 

Link: https://www.who.int/publications/m/item/who-rapid-risk-assessment---hantavirus-outbreak-caused-by-andes-virus--global-v.2

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#Ebola disease caused by #Bundibugyo virus, #DRC & #Uganda (WHO D.O.N., May 17 '26)

 

Situation at a glance

    -- On 5 May 2026, the World Health Organization (WHO) was alerted of a high-mortality outbreak of unknown illness in Mongbwalu Health Zone, Ituri Province, Democratic Republic of the Congo (DRC), including deaths among health workers. 

    -- On 14 May 2026, the Institut national de recherche biomédicale (INRB) Kinshasa analyzed 13 blood samples from Rwampara Health Zone, Ituri Province. 

    -- Laboratory analysis confirmed Bundibugyo virus disease (BVD) in eight of these samples on 15 May, a species of Ebola. 

    -- The case fatality rates in the past two BVD outbreaks have ranged from 30% to 50%. 

    -- Unlike Ebola virus disease, there is no licensed vaccine or specific therapeutics against Bundibugyo virus, though early supportive care is lifesaving. 

    -- On 15 May 2026, the Ministry of Public Health, Hygiene and Social Welfare, DRC, officially declared the 17th Ebola Disease outbreak in DRC. 

    -- Concurrently, the Uganda Ministry of Health confirmed an outbreak of BVD following the identification of one imported case from DRC, a Congolese man who died in the capital city of Kampala. 

    -- On 16 May 2026, WHO Director-General, after having consulted the States Parties where the event is known to be currently occurring, determined that the Ebola disease caused by Bundibugyo virus in DRC and Uganda constitutes a public health emergency of international concern (PHEIC), as defined in the provisions of IHR. 

    -- Response measures include deployment of rapid response teams, delivery of medical supplies, strengthened surveillance, laboratory confirmation, infection prevention and control assessments, the set-up of safe treatment centers, and community engagement. 

    -- WHO is supporting the coordination of the response, case management, and cross-border preparedness. 

    -- WHO advice has been issued to countries.

Description of the situation

    -- On 5 May 2026, WHO received an alert regarding an unknown illness with high mortality reported in Mongbwalu Health Zone, Ituri Province, including four health workers who died within four days. 

    -- Following an in-depth investigation by the rapid response team in Mongbwalu and Rwampara health zones (HZ) on 13 May, the outbreak was subsequently confirmed as Bundibugyo virus disease (BVD) due to Bundibugyo virus (BDBV) (Orthoebolavirus bundibugyoense, species) on 15 May.

    -- On 15 May 2026, the Ministry of Public Health, Hygiene and Social Welfare officially declared the 17th Ebola Disease outbreak in the DRC, occurring in Rwampara, Mongwalu and Bunia HZ.

    -- The first currently known suspected case, a health worker, reported onset of symptoms including fever, hemorrhaging, vomiting and intense malaise on 24 April 2026. The case died at a medical centre in Bunia.

    -- As of 15 May, a total of 246 suspected cases and 80 deaths (four deaths among confirmed cases) have been reported from three HZ: Rwampara (six health areas affected), Mongbwalu (three health areas affected), and Bunia .  

    -- Twenty four suspected cases are currently in isolation facilities across the three HZ.  

    -- In addition, unusual clusters of community deaths with symptoms compatible with Bundibugyo virus disease (BVD) are being investigated across other HZ in Ituri and North Kivu.

    -- A further case reported on 16 May, an individual returning from Ituri to Kinshasa, has tested NEGATIVE for Bundibugyo virus on confirmatory testing by the Institut National de la Recherche Biomédicale (INRB) of DRC, and is therefore not considered a confirmed case.

    -- Most of the suspected cases are between 20 and 39 years old, with females accounting for over 60%, suggesting significant risks associated with household and caregiver transmission.

    -- Initial testing of 20 samples collected in Rwampara HZ and analysed at the Provincial Public Health Laboratory in Bunia using standard Ebola Xpert were negative for Ebola virus. 

    -- Samples were sent to INRB for further analysis, of which eight samples analysed were confirmed as Orthoebolavirus by polymerase chain reaction (PCR) on 15 May. Genomic sequencing confirmed the virus species as Bundibugyo virus (BDBV).

    -- As of 15 May, 65 contacts have been listed, with 15 identified as high-risk. However, follow-up remains weak due to insecurity and movement restrictions. Several listed contacts became symptomatic and died before they could be isolated.

    -- On 15 May 2026, the Ministry of Health of Uganda confirmed an outbreak of BVD following the identification of an imported case from the DRC. 

    -- The case is an elderly man who was admitted to a private hospital on 11 May with severe symptoms and died on 14 May. 

    -- The post-mortem transfer of the body to DRC was completed the same day. 

    -- A clinical sample collected when the case was admitted on 11 May was tested at the Central Emergency Surveillance and Response Support Laboratory, Wandegeya, and was confirmed as Bundibugyo virus on 15 May 2026. 

    -- A second imported case was confirmed on 16 May in Kampala, in an individual returning from DRC with no apparent links to the first case. 

    -- At the time of reporting, no local transmission has been identified in Uganda.

    -- On 16 May 2026, the Director-General of WHO, after having consulted the States Parties where the event is known to be currently occurring as defined in the provisions of the International Health Regulations (2005) (IHR), determined that the Ebola disease caused by Bundibugyo virus in DRC and Uganda constitutes a PHEIC.

    -- It is currently thought that the event originated in the Mongbwalu HZ, DRC, a high-traffic mining area, with cases subsequently migrating to Rwampara and Bunia to seek medical care. 

    -- Ituri province borders South Sudan and Uganda (and Bunia HZ is less than 500km from Uganda). 

    -- A full epidemiological investigation and trace back exercise is ongoing.

    -- Ituri’s role as a commercial and migratory hub and proximity to Uganda and South Sudan increases the risk of regional exportation and cross-border transmission.

Epidemiology

    -- Bundibugyo virus disease (BVD) is a severe and often fatal form of Ebola disease caused by the Bundibugyo virus, one of the Orthoebolavirus species. 

    -- It is a zoonotic disease, with fruit bats suspected to be the natural reservoir. 

    -- Human infection occurs through close contact with the blood or secretions of infected wildlife, such as bats or non-human primates, and subsequently spreads from person to person through direct contact with the blood, secretions, organs, or other bodily fluids of infected individuals or contaminated surfaces. 

    -- Transmission is particularly amplified in health-care settings when infection prevention and control (IPC) measures are inadequate, and during unsafe burial practices involving direct contact with the deceased.

    -- The incubation period for BVD ranges from 2 to 21 days, and individuals are usually not infectious until symptom onset. 

    -- Early symptoms are non-specific, including fever, fatigue, muscle pain, headache, and sore throat, which complicates clinical diagnosis and can delay detection. 

    -- These progress to gastrointestinal symptoms, organ dysfunction, and in some cases haemorrhagic manifestations. 

    -- Case fatality rates in the past two BVD outbreaks, reported in Uganda and in DRC in 2007 and 2012, have ranged from approximately 30% to 50%.

    -- Differentiating BVD from other endemic febrile illnesses such as malaria is challenging without laboratory confirmation using PCR or antigen/antibody-based assays. 

    -- Control relies on rapid case identification, isolation and care, contact tracing, safe burials, and strong community engagement, as no approved vaccines or specific treatments currently exist for BVD.

Public health response

    -- Health authorities in DRC are implementing public health measures, including but not limited to the following:

Coordination

    ° Rapid response teams have been deployed to Rwampara and Mongbwalu HZ.

    ° Provincial coordination and emergency meetings by le centre d’operation des urgences en sante publique (COUSP) have been held.

Surveillance and Laboratory

    ° Surveillance for suspected and probable cases is ongoing (including at relevant Points of Entry and borders).

    ° Operational case definitions have been elaborated in Ituri.

    ° Sequencing confirmed Bundibugyo virus in positive RT-PCR samples.

Risk Communication and Community Engagement (RCCE)

    ° Social mobilization meeting was held with community leaders in the Rural commune of Mongbwalu under the leadership of the Mayor.

Infection Prevention and Control (IPC)

    ° IPC assessment in key health facilities is ongoing: Bunia Hospital Centre of the Evangelical Medical Centre (CME), Mongbwalu General Referral Hospital and Abelkozo Health Centre.

    ° CME Bunia is maintaining isolation protocols. Healthcare workers have been briefed on the specific diagnostic profile of this strain.

Logistics

    ° Logistical support has been provided for investigations in Mongbwalu and Rwampara Health Zones.

    ° Support has been provided for the transportation of samples to INRB Kinshasa.

    ° Health authorities in Uganda are implementing public health measures, including but not limited to the following:

    -- Activating national and district-level emergency measures, including enhanced surveillance, screening at borders, deployment of rapid response teams, isolation of a high-risk contact, and quarantine of all identified contacts.

    -- Strengthening of preparedness activities such as mobile laboratory deployment, infection prevention, and risk communication.

    -- Rapid response readiness teams have been deployed at all official and informal points of entry along the western border, major transit routes, and pilgrimage corridors.

    -- Advising health workers to remain vigilant and adhere strictly to infection prevention measures.

    -- WHO is supporting the national authorities, including through:

        - Deployment of technical expertise and rapid response teams to support response efforts.

        - Deployment of IPC, clinical management and sample collection kits.

        - Identification of isolation facilities for case management in Bunia, Rwampara, and Mongbwalu HZ .

        - Dissemination of WHO case management protocol.

        - In-depth investigations and listing of contacts of suspected/probable cases.

        - Strengthening epidemiological surveillance, IPC and RCCE at all points of entry.

        - Strengthening Point of Entry (PoE) screening and cross border coordination, including mass gatherings.

        - Supporting the Ministry of Health in implementation of the Response Plan and WHO internal Response Plan.

        - Following up with the IHR National Focal Points (IHR NFP) in DRC and Uganda on the official IHR notification while concurrently managing communication across the IHR NFP network to ensure timely coordination.

        - Coordinating the delivery of key supplies.

        - Engaging experts on research and development priorities. 

WHO risk assessment

    -- On 16 May 2026, WHO Director-General, after having consulted the States Parties where the event is known to be currently occurring, determined that the Ebola disease caused by Bundibugyo virus in the Democratic Republic of the Congo and Uganda constitutes a public health emergency of international concern (PHEIC), as per the provisions of the IHR. Temporary recommendations for State Parties will be issued.  In the meantime, WHO issued advice to countries, as stated below.

    -- This is the 17th Ebola disease outbreak in the DRC since 1976. The last Ebola disease outbreak in the country was declared on 4 September 2025 with total of 64 cases (53 confirmed, 11 probable), including 45 deaths (CFR 70.3%), reported from six health areas in Bulape Health Zone, Kasai Province. 

    -- The end of outbreak was declared on 1 December 2025. 

    -- The last BVD outbreak was reported on 17 August 2012 by the DRC Ministry of Health in Province Orientale.  A total of 59 cases, 38 confirmed and 21 probable cases, including 34 deaths were reported. The outbreak was declared over on 26 November 2012 by the MOH.

    -- This outbreak is occurring in a complex epidemiological and humanitarian context. 

    -- A critical four-week detection gap between the onset of symptoms of the presumed index case (25 April 2026) and the laboratory confirmation of the outbreak (14 May 2025) suggests a low clinical index of suspicion among healthcare providers. This is compounded by the presence of co-circulating arboviruses and influenza-like illnesses, masking the initial index of suspicion for Ebola disease and exacerbating community transmission. 

    -- Furthermore, the infection and death of four healthcare workers within a four-day span at Mongbwalu General Referral Hospital underscores critical breaches in IPC protocols. A large number of community deaths has been reported potentially associated with unsafe burial practices.

    -- Ongoing conflict in Ituri province restricts the movement of surveillance teams, limits the deployment of Rapid Response Teams, and hinders the secure transport of laboratory samples. Contact tracing is challenging due to difficult access and highly mobile populations, increasing the risk of high-risk contacts being lost to follow up or never identified.

    -- Ituri’s role as a commercial and migratory hub increases the risk of regional exportation. The proximity to Uganda and South Sudan increases the risk of cross-border transmission if PoE screening and cross border coordination and information sharing are not immediately reinforced. On 15 May 2026, the Ministry of Health of Uganda reported an imported case of BVD.

    -- Humanitarian needs in the area are dire. Ituri has 273 403 displaced people, with a total of 1.9 million people in need according to the Humanitarian Response Plan 2026 for DRC. From January to March 2026, 32 600 newly displaced and 30 200 returnees were recorded. The province recorded 5800 protection incidents and 11 incidents against humanitarian actors.

    -- Unlike Ebola virus disease, there is no licensed vaccine or specific therapeutics against BDBV. Research and development activities are activated to coordinate efforts to advance potential candidate medical countermeasures. Response and outbreak control relies entirely on a range of interventions and public health measures that will need to be thoroughly implemented, including supportive care, early detection, adequate IPC, rigorous contact tracing, safe burials, and community engagement.

WHO advice

    -- For countries where the event is occurring (the Democratic Republic of the Congo and Uganda)

Coordination and high-level engagement

    ° Activate their national disaster/emergency management mechanisms and establish an emergency operation centre, under the authority of the Head of State and relevant government authority, to coordinate response activities across partners and sectors to ensure efficient and effective implementation and monitoring of comprehensive Bundibugyo virus disease control measures. These measures must include enhanced surveillance including contact tracing, infection prevention and control (IPC), risk communication and community engagement, laboratory diagnostic testing, and case management. Coordination and response mechanisms should be established at national level, as well as at subnational level in affected areas and at-risk areas.

    ° Should national capacities be overwhelmed, collaboration with partners should be enhanced to strengthen operations and ensure the ability to implement control measures in all affected and neighbouring areas. 

Risk communication and community engagement 

    ° Ensure that there is a large-scale and sustained effort to fully engage the community – through local, religious and traditional leaders and healers – so communities play a central role in case identification, contact tracing and risk education; the population should be made fully aware of the benefits of early treatment.

    ° Strengthen community awareness, engagement, and participation in particular to identify and address cultural norms and beliefs that serve as barriers to their full participation in the response, and integrate the response within the wider response required to address the needs of the population, particularly in contexts of the protracted humanitarian crisis in Eastern DRC.

Surveillance and laboratory  

    ° Strengthening surveillance and laboratory capacity across affected provinces and neighbouring provinces, through the establishment of (1) dedicated surveillance and response cells within affected health zones and across key at-risk neighbouring health zones; (2) enhanced community surveillance, particularly focused on community deaths; and (3) decentralized laboratory capacity for testing of Bundibugyo virus. 

Infection prevention and control in health facilities and in the context of care

    ° Strengthen measures to prevent nosocomial infections, including systematic mapping of health facilities, triage, targeted IPC interventions and sustained monitoring and sustained supervision.

    ° Ensure healthcare workers receive adequate training on IPC, including the proper use of PPE, and that health facilities have appropriate equipment to ensure the safety and protection of their staff, their timely payment of salaries and, as appropriate, hazard pay.

    ° Patients’ referral pathway and access to safe and optimized intensive care. 

    ° Ensure that suspected cases can be safely transferred to specialized clinical units for their isolation and management in a human and patient-centred approach.

    ° Establish specialized treatment centers or units, located close to outbreak epicenter(s), with staff trained and equipped to implement optimized intensive supportive care. 

Research and development of medical countermeasures

    ° Implement clinical trials to advance the development and use of candidate therapeutics and vaccine, supported by partners. 

Border health, travels and mass-gathering events 

    ° Undertake cross-border screening and screening at main internal roads to ensure that no suspected case is missed and enhance the quality of screening through improved sharing of information with surveillance teams.

    ° There should be no international travel of Bundibugyo virus disease contacts or cases, unless the travel is part of an appropriate medical evacuation. To minimize the risk of international spread of Bundibugyo virus disease:

    ° Confirmed cases should immediately be isolated and treated in a Bundibugyo virus disease Treatment Centre with no national or international travel until two Bundibugyo virus-specific diagnostic tests conducted at least 48 hours apart are negative;

    ° Contacts (which do not include properly protected health workers and laboratory staff who have had no unprotected exposure) should be monitored daily, with restricted national travel and no international travel until 21 days after exposure;

    ° Probable and suspect cases should immediately be isolated and their travel should be restricted in accordance with their classification as either a confirmed case or contact.

    ° Implement exit screening of all persons at international airports, seaports and major land crossings, for unexplained febrile illness consistent with potential Bundibugyo virus disease. The exit screening should consist of, at a minimum, a questionnaire, a temperature measurement and, if there is a fever, an assessment of the risk that the fever is caused by Bundibugyo virus disease. Any person with an illness consistent with Bundibugyo virus disease should not be allowed to travel unless the travel is part of an appropriate medical evacuation.

    ° Consider postponing mass gatherings until BVD transmission is interrupted.

Safe and dignified burials 

    ° Ensure funerals and burials are conducted by well-trained personnel, with provision made for the presence of the family and cultural practices, and in accordance with national health regulations, to reduce the risk of Bundibugyo virus infection. The cross-border movement of the human remains of deceased suspect, probable or confirmed Bundibugyo virus disease cases should be prohibited unless authorized in accordance with recognized international biosafety provisions.

Operations, supplies and logistics

    ° Strong supply pipeline needs to be established to ensure that sufficient medical and laboratory commodities and other critical items, especially personal protective equipment (PPE), are available to those who appropriately need them. WHO advises against any restrictions on travel and/or trade to DRC or Uganda based on available information for the current outbreak.

For countries with land borders adjoining countries with documented Bundibugyo virus disease 

    ° Unaffected States Parties with land borders adjoining States Parties with documented Bundibugyo virus disease  transmission should urgently enhance their preparedness and readiness capacity, including active surveillance across health facilities with active zero reporting, enhancement of community surveillance for clusters of unexplained deaths; establish access to a qualified diagnostic laboratory; ensure that health workers are aware of and trained in appropriate IPC procedures; and establish rapid response teams with the capacity to investigate and manage BVD cases and their contacts.

    ° Dedicated coordination mechanisms should be in place at national and subnational level in all Unaffected States Parties with land borders adjoining States Parties with documented cases of Bundibugyo virus disease. States should be prepared to detect, investigate, and manage Bundibugyo virus disease cases; this should include assured access to a qualified diagnostic laboratory for Bundibugyo virus disease, isolation and case management capacity and activation of rapid response teams. 

    ° Any State Parties newly detecting a suspected or confirmed Bundibugyo virus disease case or contact, or clusters of unexplained deaths should treat this as a health emergency, take immediate steps in the first 24 hours to investigate and stop a potential outbreak by instituting case isolation, case management, establishing a definitive diagnosis, and undertaking contact tracing and monitoring as required.

    ° If Bundibugyo virus disease is confirmed to be occurring in the State Party, the full recommendations for State Parties with Bundibugyo virus disease transmission should be implemented, on either a national or subnational level, depending on the epidemiologic and risk context. State Parties should immediately report the confirmation of Bundibugyo virus disease to WHO.

    ° Risk communications and community engagement, especially at points of entry, should be increased.

    ° At-risk countries should put in place approvals for investigational therapeutics as an immediate priority for preparedness.

For all other countries

    ° No country should close its borders or place any restrictions on travel and trade. Such measures are usually implemented out of fear and have no basis in science. They push the movement of people and goods to informal border crossings that are not monitored, thus increasing the chances of the spread of disease. Most critically, these restrictions can also compromise local economies and negatively affect response operations from a security and logistics perspective.

    ° National authorities should work with airlines and other transport and tourism industries to ensure that they do not exceed WHO’s advice on international traffic.

    ° States Parties should provide travelers to Bundibugyo virus disease affected and at-risk areas with relevant information on risks, measures to minimize those risks, and advice for managing a potential exposure.

    ° The general public should be provided with accurate and relevant information on the Bundibugyo virus disease outbreak and measures to reduce the risk of exposure.

    ° State Parties should be prepared to facilitate the evacuation and repatriation of nationals (e.g. health workers) who have been exposed to Bundibugyo virus disease.

    ° Entry screening at airports or other ports of entry outside the affected region are not considered needed for passengers returning from areas at risk.

Further information

-- Epidemic of Ebola Disease caused by Bundibugyo virus in the Democratic Republic of the Congo and Uganda determined a public health emergency of international concern.  https://www.who.int/news/item/17-05-2026-epidemic-of-ebola-disease-in-the-democratic-republic-of-the-congo-and-uganda-determined-a-public-health-emergency-of-international-concern

-- The Ministry of Public Health, Hygiene and Social Welfare, DRC, officially declares the 17th Ebola Disease outbreak. https://administration.sante.gouv.cd/wp-content/uploads/2026/05/Declaration-de-la-17e-Epidemie-de-la-maladie-a-virus-Ebola-dans-les-zones-de-sante-de-Rwampara-Mongwalu-et-Bunia-dans-la-province-dIturi.pdf

-- WHO Democratic Republic of Congo confirms new Ebola outbreak.  https://www.afro.who.int/countries/democratic-republic-of-congo/news/democratic-republic-congo-confirms-new-ebola-outbreak-who-scales-upsupport

-- Ebola  disease fact sheet: http://www.who.int/en/news-room/fact-sheets/detail/ebola-virus-disease

-- Disease Outbreak News. Ebola outbreak in Democratic Republic of Congo – update. WHO. 14 September 2012: Ebola outbreak in Democratic Republic of Congo – update

-- Disease Outbreak News. Ebola outbreak in Democratic Republic of Congo – update. WHO. 26 October 2012: Ebola outbreak in Democratic Republic of Congo – update

-- WHO Launches Online Training to Strengthen Filovirus Outbreak Response. https://www.who.int/news/item/26-03-2025-who-launches-online-training-to-strengthen-filovirus-outbreak-response#

-- Infection prevention and control guideline for Ebola and Marburg disease. WHO. August 2023: https://www.who.int/publications/i/item/WHO-WPE-CRS-HCR-2023.1

-- Infection prevention and control and water, sanitation and hygiene in health facilities during Ebola or Marburg disease outbreaks: rapid assessment tool, user guide https://www.who.int/publications/i/item/9789240107205

-- Assessment and management of health and care workers with possible occupational exposures to Orthoebolavirus or Orthomarburgvirus: implementation guidance https://www.who.int/publications/i/item/9789240107328

-- Optimized Supportive Care for Ebola Virus Disease. Clinical management standard operating procedures. WHO. 2019. https://www.who.int/publications/i/item/9789241515894 

-- Ebola clinical management. https://www.who.int/teams/health-care-readiness/ebola-clinical-management 

-- Framework and toolkit for infection prevention and control in outbreak preparedness, readiness and response at the national level. https://www.who.int/publications/i/item/framework-and-toolkit-for-infection-prevention-and-control-in-outbreak-preparedness--readiness-and-response-at-the-health-care-facility-level

-- Considerations for border health and points of entry for filovirus disease outbreaks: https://www.who.int/publications/m/item/considerations-for-border-health-and-points-of-entry-for-filovirus-disease-outbreaks

-- Diagnostic testing for Ebola and Marburg virus diseases: interim guidance, 20 December 2024: https://www.who.int/publications/i/item/B09221 

Citable reference: World Health Organization (17 May 2026). Disease Outbreak News; Bundibugyo Virus Disease, Democratic Republic of the Congo (The) and Uganda. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON602 

Source: 

Link: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON602

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#Statement on the #antigen #composition of #COVID19 #vaccines (#WHO, May 16 '26)

 

Key points:

    -- The WHO Technical Advisory Group on COVID-19 Vaccine Composition (TAG-CO-VAC) held its twice-yearly decision-making meeting in May 2026 to review the evolution of SARS-CoV-2, the effectiveness of currently approved COVID-19 vaccines and the implications for COVID-19 vaccine antigen composition.

    -- The objective of any update to COVID-19 vaccine antigen composition is to enhance vaccine-induced immune responses to circulating SARS-CoV-2 variants, when needed.

    -- Following this meeting, the TAG-CO-VAC advises vaccine manufacturers that monovalent LP.8.1 is the recommended vaccine antigen.

    -- Other antigens (e.g. XFG, NB.1.8.1) or other approaches that demonstrate broad and robust neutralizing antibody responses or efficacy against currently circulating SARS-CoV-2 variants could also be used.

    -- Vaccination remains an important public health countermeasure against COVID-19 and vaccination should not be delayed in anticipation of access to vaccines with an updated antigen composition. As per the March 2026 WHO Strategic Advisory Group of Experts on Immunization (SAGE) recommendations, Member States should consider routine COVID-19 vaccination of groups at highest risk of severe COVID-19 disease.

    -- The WHO Technical Advisory Group on COVID-19 Vaccine Composition (TAG-CO-VAC) continues to closely monitor the genetic and antigenic evolution of SARS-CoV-2 variants, immune responses to SARS-CoV-2 infection and COVID-19 vaccination, and the effectiveness of COVID-19 vaccines against circulating variants. 

    -- Based on these evaluations, WHO advises vaccine manufacturers and regulatory authorities on the implications for future updates to COVID-19 vaccine antigen composition. 

    -- In December 2025, the TAG-CO-VAC advised vaccine manufacturers that monovalent LP.8.1 is the recommended vaccine antigen. Multiple manufacturers (using mRNA or recombinant protein-based vaccines) have updated COVID-19 vaccine antigen composition to monovalent LP.8.1 formulation. Several of these vaccines have been approved for use by regulatory authorities and have been introduced into vaccination programmes. Previous statements from the TAG-CO-VAC can be found on the WHO website.

    -- The TAG-CO-VAC reconvened on 7-8 May 2026 to review the genetic and antigenic evolution of SARS-CoV-2; immune responses to SARS-CoV-2 infection and/or COVID-19 vaccination; the effectiveness of currently approved vaccines against circulating SARS-CoV-2 variants; and the implications for COVID-19 vaccine antigen composition.

Evidence reviewed

    -- The published and unpublished evidence reviewed by the TAG-CO-VAC included: 

    (1) SARS-CoV-2 genetic evolution, with additional support from the WHO Technical Advisory Group on Virus Evolution (TAG-VE); 

    (2) Antigenic characterization of previous and emerging SARS-CoV-2 variants using virus neutralization tests with animal antisera and further analysis of antigenic relationships using antigenic cartography; 

    (3) Immunogenicity data on the breadth of neutralizing antibody responses elicited by currently approved vaccine antigens against circulating SARS-CoV-2 variants using animal and human sera, with additional support from WHO Coronavirus Network (CoViNet); 

    (4) Preliminary clinical immunogenicity data on immune responses following infection with circulating SARS-CoV-2 variants; 

    (5) Available COVID-19 vaccine effectiveness (VE) estimates of currently approved vaccines; and 

    (6) Preliminary non-clinical and clinical immunogenicity data on the performance of candidate vaccines with updated antigens shared by vaccine manufacturers with TAG-CO-VAC. 

    Further details on the data reviewed by the TAG-CO-VAC can be found in the accompanying data annex. Confidential data reviewed by the TAG-CO-VAC are not shown.

Summary of available evidence

    There are persistent and increasing gaps and delays in the surveillance and reporting of cases, hospitalizations and deaths from WHO Member States, limiting the interpretation and comparability of epidemiological trends over time. 

    In 2026, SARS-CoV-2 continues to circulate globally, causing severe disease, post COVID-19 condition, and death. 

    However, the impact on health systems has reduced substantially compared to 2020-2021 due to multiple factors, including increased population immunity from infection and/or vaccination and improved clinical management. 

    In 2026, all WHO regions are reporting lower SARS-CoV-2 test positivity rates than during the corresponding period in previous years.

    Globally, the current predominant variant among SARS-CoV-2 sequences remains Variant Under Monitoring (VUM) XFG, however the weekly proportion is now declining. 

    In contrast, in countries in the WHO Western Pacific Region where sequencing continues, VUM NB.1.8.1 is the predominant variant. 

    Globally, the proportion of VUM BA.3.2 is increasing, with heterogeneous dynamics across countries where genomic surveillance continues. 

    BA.3.2 appears to have lower fitness than JN.1-descendant variants, which may explain why BA.3.2 has not displaced JN.1-descendant variants in regions where it has been detected. 

    To date, the increase in the proportion of BA.3.2 does not appear to be associated with a substantial increase in disease burden, unlike increases associated with previous Variants of Interest and JN.1-descendant variants. 

    In several countries, BA.3.2 appears to account for a higher proportion of sequences from young children than adults, suggesting possible differences in susceptibility to BA.3.2 related to a lack of cross-reactive immunity generated by previous exposure to early SARS-CoV-2 variants. 

    However, sequence numbers and the reported number of infected individuals, including those with severe disease, remain low; this observation should therefore be interpreted with caution.

    Neutralization data using antisera from naïve animals infected or vaccinated with JN.1, LP.8.1, NB.1.8.1 or XFG, indicated that recent JN.1-descendant variants are antigenically closely related. 

    These variants differed by approximately 1 antigenic unit in cartographic analyses, corresponding to a two-fold-difference in neutralization, with XFG often the most antigenically distant from JN.1 within the JN.1 cluster. 

    In contrast, these antisera showed limited neutralizing activity against BA.3.2. 

    Antisera from naïve animals infected with BA.3.2 showed very limited cross-reactivity with recent JN.1-descendant variants. 

    Together, these results indicate that BA.3.2 is antigenically distinct from JN.1- descendant variants.

    Sera from cohorts that are representative of recent population immunity and pre-LP.8.1 vaccination sera demonstrated cross-reactivity with recent JN.1-descendant variants and with BA.3.2.

    Pre- and post-vaccination sera from individuals immunized with LP.8.1 demonstrated significant increases in neutralizing activity against JN.1 and its descendant variants, including NB.1.8.1 and XFG. 

    Post-vaccination neutralizing antibody titers and the fold change against BA.3.2 were lower than against the homologous LP.8.1 antigen and other JN.1- descendant variants.

    Pre- and post-vaccination sera from individuals immunized with JN.1 or KP.2 demonstrated significant increases in neutralizing activity against JN.1 and its descendant variants. 

    However, post-vaccination neutralizing antibody titers against NB.1.8.1 and XFG were lower than those against the homologous JN.1 or KP.2 antigens, with even larger reductions typically observed for BA.3.2.

    Contemporary vaccine effectiveness (VE) estimates are relative (rVE) and demonstrate the added or incremental protection of recent vaccination over and above pre-existing infection- and vaccine-derived immunity. 

    Monovalent JN.1 and KP.2 mRNA vaccines demonstrated additional protection—relative to pre-existing immunity—against symptomatic and severe COVID-19. 

    The limited number of rVE estimates using monovalent LP.8.1 vaccines also demonstrated additional protection against symptomatic and severe COVID-19.

    Data shared with the TAG-CO-VAC by vaccine manufacturers showed that:

      - Immunization of naïve mice with monovalent LP.8.1, XFG or NB.1.8.1 induced high neutralizing antibody titers against the homologous antigen, as well as other JN.1-descendant variants. 

    - Low or non-detectable neutralizing antibody titers were consistently observed against BA.3.2. 

    - In contrast, immunization of naïve mice with monovalent BA.3.2 induced immune responses largely restricted to the homologous antigen. 

    - Overall immunogenicity of BA.3.2 was lower than after LP.8.1, XFG or NB.1.8.1 immunization.

    - Immunization of mice previously immunized with SARS-CoV-2 variants and then immunized with LP.8.1, XFG or NB.1.8.1 induced high neutralizing antibody titers against JN.1-descendant variants. 

    - Lower neutralizing antibody titers against BA.3.2 were observed. 

    - Immunization with BA.3.2 induced neutralizing titers against the homologous antigen, and to a lesser extent against JN.1-descedant variants. 

    - However, overall immunogenicity of BA.3.2 was lower than after LP.8.1, XFG or NB.1.8.1 immunization.

    - In humans, vaccination with 8.1 induced strong increases in neutralizing antibody titers against JN.1, LP.8.1, NB.1.8.1 and XFG. 

    - As in mice, post- vaccination neutralizing antibody titers against BA.3.2 were lower than those against the homologous LP.8.1 antigen. 

    - A single clinical immunogenicity study using a BA.3.2 vaccine candidate showed increased neutralizing antibody titers against the homologous antigen, and a back boost against JN.1-descendant variants, but overall lower immunogenicity than the LP.8.1 vaccine.

    - Overall, LP.8.1 as a vaccine antigen in populations with high levels of prior infection and / or vaccination continues to induce broadly cross-reactive immune responses to circulating SARS-CoV-2 variants.

    -- The TAG-CO-VAC acknowledges several limitations of available data:

    - There are persistent and increasing gaps and delays in the reporting of cases, hospitalizations and deaths, from WHO Member States, as well as in genetic/genomic surveillance of SARS-CoV-2 globally, including low numbers of samples sequenced and limited geographic diversity. The TAG-CO-VAC strongly supports the ongoing work of the WHO Coronavirus Network (CoViNet) and the Global Influenza Surveillance and Response System (GISRS) to address this information gap.

    - The timing, specific mutations and antigenic characteristics of emerging and future variants are difficult to predict, and the potential public health impact of these variants remain unknown. Currently, two antigenically distinct lineages (JN.1-descendant and BA.3.2-descendant variants) are circulating and the comparative evolutionary potential of these lineages remains uncertain. Variants derived from these lineages will continue to be monitored and/or characterized, and the TAG-CO-VAC strongly supports the ongoing work of the TAG-VE. 

    - Although neutralizing antibody titers have been shown to be important correlates of protection from SARS-CoV-2 infection and of estimates of vaccine effectiveness, there are multiple components of immune protection elicited by infection and/or vaccination. Data on the immune responses following JN.1-descendant variant infection or monovalent LP.8.1 vaccination are largely restricted to neutralizing antibodies. Data and interpretation of other aspects of the immune response, including cellular immunity, are limited. 

    - Immunogenicity data against currently circulating SARS-CoV-2 variants are not available for all COVID-19 vaccines. 

    - Recent estimates of rVE are limited in terms of the number of studies, geographic diversity, vaccine platforms evaluated, populations assessed, duration of follow-up, and contemporary comparisons of vaccines with different antigen composition. There are currently only a limited number of available rVE estimates using monovalent LP.8.1 mRNA vaccines; there are no rVE estimates in populations in which BA.3.2 was the predominant variant.

Recommendations for COVID-19 vaccine antigen composition

    -- Monovalent LP.8.1 (Nextstrain: 25A; GenBank: PV074550.1; GISAID: EPI_ISL_19467828) is the recommended COVID-19 vaccine antigen.

    -- Other antigens (e.g. XFG, NB.1.8.1) or other approaches that demonstrate broad and robust neutralizing antibody responses or efficacy against currently circulating SARS-CoV-2 variants could also be used.

    -- As per the March 2026 WHO Strategic Advisory Group of Experts on Immunization (SAGE) recommendations, Member States should consider routine COVID-19 vaccination of groups at highest risk of severe COVID-19 disease and vaccination should not be delayed in anticipation of access to vaccines with an updated antigen composition.

Further data requested

    -- Given the limitations of the evidence upon which the recommendations above are derived and the anticipated continued evolution of the virus, the TAG-CO-VAC strongly encourages generation of the following data (in addition to the types of data outlined in March 2026)

    - Immune responses and clinical endpoints (i.e. VE and/or comparator rates of infection and severe disease) in varied human populations who receive currently approved COVID-19 vaccines against emerging SARS-CoV-2 variants, across different vaccine platforms.

    - Strengthened epidemiological and virological surveillance, as per the Standing Recommendations for COVID-19 in accordance with the International Health Regulations (2005), to determine if emerging variants are antigenically distinct and able to displace circulating variants.

    - Strengthened epidemiological surveillance to characterize disease severity in immunologically naïve and/ or immature individuals (e.g. young pediatric cohorts), particularly for BA.3.2 infections.

    - Non-clinical and clinical immunogenicity data against circulating SARS-CoV-2 variants for vaccine candidates with different SARS-CoV-2 antigens.

    - As previously stated, the TAG-CO-VAC continues to encourage the further development of vaccines that may improve protection against infection and reduce transmission of SARS-CoV-2.

    -- The TAG-CO-VAC will continue to closely monitor the genetic and antigenic evolution of SARS-CoV-2 variants, immune responses to SARS-CoV-2 infection and COVID-19 vaccination, and the effectiveness of COVID-19 vaccines against circulating variants. The TAG-CO-VAC will also continue to reconvene every six months, or as needed, to evaluate the implications for COVID-19 vaccine antigen composition. At each meeting, recommendations to either maintain current vaccine composition or to consider updates will be issued. Prior to each meeting, the TAG-CO-VAC will publish an update to the statement on the types of data requested to inform COVID-19 vaccine antigen composition deliberations.

Source: 

Link: https://www.who.int/news/item/16-05-2026-statement-on-the-antigen-composition-of-covid-19-vaccines

____

#Hantavirus #cluster linked to cruise ship travel, Multi-country (#WHO D.O.N., May 13 '26)

 

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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