Showing posts with label multi-country outbreak. Show all posts
Showing posts with label multi-country outbreak. Show all posts

Tuesday, August 25, 2026

#Mpox, Multi-Country #Outbreak - Rapid #risk #assessment V7 (#WHO, August 25 '26)



{Summary}

    ° Date and version of current assessment: 18 August 2026, v7

    ° Overal Global Risk statement: 

        § This global rapid risk assessment (RRA) assessesthe current public health  risk associated with the 2024 upsurge of mpox in Africa, in the context of the  continuing global occurrence of mpox in all regions since 2022, with a focus on  updates since the previous RRA in February 2026. 

        § The overall public health risk  posed by mpox remains unchanged from the last RRA. 


Global overview

    As of 30 June 2026, the monkeypox virus (MPXV) continues to spread  globally, causing both localized and extended mpox outbreaks driven by multiple  MPXV clades (Ia, Ib, IIa, and IIb) in diverse settings. The recombination of MPXV clades has also been documented, with the two previously reported cases  of a recombinant clade Ib/IIb MPXV strain detected in the United Kingdom of Great Britain and Northern Ireland in late 2025 and India in January 2026,  and one additional case reported in Qatar since the last RRA.

    Globally, from 1 January 2022 to 30 June 2026, 145 countries and  territories across all WHO regions reported 188 847 confirmed cases of mpox,  with 521 deaths [case fatality ratio (CFR) – 0.3%] and including two  additional countries: Comoros and Guinea-Bissau

    Since the last RRA, an additional 10 908 confirmed cases, 44 deaths,  and an average of 420 new confirmed mpox cases per week have been reported  across all affected countries. 

    As with the previous version, this RRA assesses the risk for three population groups

        i) global risk for individuals with multiple sexual partners, 

        ii) risk for children in mpox historically endemic areas where risk of zoonotic  transmission continues, and 

        iii) global risk for all other individuals. Updates in understanding of mpox  epidemiology within these groups are described herein.


Individuals with multiple sexual partners – global risk

    Since the start of the global mpox outbreak in 2022, sexual activity in  linked sexual networks has been the primary driver of sustained transmission and  geographic spread, particularly in newly affected areas. The major and  predominant contribution of sexual transmission, whether linked to  heterosexual or same-sex contact, to the introduction, spread and  establishment of mpox in communities has been recognized across all affected  settings. 

    Outside the WHO African Region, over 87% of reported cases have been among men who have sex with men (MSM), with transmission driven by  spread among individuals with multiple sexual partners in a short time span  and/or frequent partner change

    Outbreaks are commonly linked to a sex-on-premises location or event.  In Africa, transmission has often been reported to involve sex workers and their  clients, long-distance drivers and other sexual networks where people have  multiple partners and/or frequent partner change. In Africa, most transmission  appears to be heterosexual.

    In networks characterized by multiple partners and/or frequent partner  change over short periods (days to a few weeks), the secondary attack rate for  sexual contact may be high (estimated at 73% in some settings), facilitating epidemic spread. This pattern was observed during the initial spread of  clade IIb MPXV among MSM communities and more recently clade Ib and IIb  MPXV outbreaks in Africa and elsewhere, with amplification in key populations  such as female sex workers and their clients as well as others with multiple  partners, often in different locations. The recently identified recombinant clade  Ib/IIb strain of MPXV has also been identified in this group with similar risk factors  related to sexual contact. This risk group therefore includes people with multiple or frequently changing sex partners, including those with higher-risk  sexual behaviours.

    Sexual contact transmission likely occurs during various stages of  infection, including pre-symptomatic or less apparent stages, the duration of  which can vary between individuals. People with few or mild genital lesions might not recognise the infection. Studies have shown that the virus can be  present in genital and anal mucosae, as well as in seminal and vaginal fluids  of symptomatic infected individuals. Emerging data suggests that viral  shedding from the genitals may occur up to four days before symptom onset,  potentially contributing to undetected sexual contact transmission. This could  explain the persistence of the virus in communities and the challenges  encountered in interrupting human-tohuman transmission, while the contribution  of asymptomatic viral carriage to transmission remains unclear.

    In most healthy adults of this group, mpox is often self-limiting.  However, severe disease, including disabling complications, secondary infections,  long-term sequelae and death, continues to occur most particularly but not exclusively in people living with advanced HIV disease or uncontrolled HIV  infection, as well as other immunocompromising conditions. While overall case  fatality has remained below 1% in most settings, up to 15-fold or higher fatality has been observed among individuals with immunosuppression, as well as in vulnerable infants, and particularly neonates  in some settings. Notably, recent data from the African setting support  observations elsewhere that people living with HIV who have suppressed viral loads and preserved CD4 counts experience mortality equivalent to HIV-negative individuals, indicating that the HIV-associated  mortality risk is largely modifiable and deaths are preventable through sustained  viral suppression and immune reconstitution. Although most people living with HIV globally are on antiretroviral therapy, significant and growing gaps in  diagnosis and treatment persist in several lowand middle-income settings, with  26.3 million people estimated to be living with HIV in Africa in 2025, of which over 20% either do not know their status, are not on antiretroviral therapy or are  not successfully virally suppressed, a situation exacerbated by recent funding cuts  to HIV control programmes in many countries. In many contexts, over half of mpox cases are reported among people living with HIV, adding  more complexity to the convergence of risks faced by this group (risk of infection,  risk of severe disease, and risk of poorer health service access).

    Most countries globally have activated outbreak responses, including  surveillance, case investigation, contact tracing, case management, and infection  prevention and control. However, control efforts have been impeded when sexual contact transmission or other risk factors are not adequately recognized, or  when risk communication and community engagement do not effectively reach  key populations and other individuals within sexual networks. Furthermore, countries are increasingly tasking HIV/STI control programmes –  themselves heavily constrained by recent funding cuts – with participating in or  leading the response, as well as activating immunization policies and programme  capacity.

    While targeted mpox vaccination has been implemented for groups at  higher risk of mpox exposure in many countries in high and low-income settings,  including administration of more than two million doses in Africa, coverage  remains uneven or partial and most individuals in this group remain susceptible to  MPXV infection, particularly in countries outside Europe and North America. In  addition, younger cohorts are continually entering sexually active age groups.

    The duration and level of protection conferred by prior infection and/or vaccination remains uncertain

    Overall, transmission in these groups at higher risk is ongoing and likely  to continue to spread geographically, which can be expected to lead to  severe outcomes among immunocompromised individuals, thus focusing  risk of spread among individuals with multiple partners in interconnected sexual  networks who may not be aware of risk, and the risk of complications and death  among vulnerable individuals. 

    The overall public health risk for individuals with  multiple sexual partners is, therefore, assessed as moderate.


Children in historically endemic areas – local risk

    In historically endemic areas in West and Central African countries,  where viruses continue to circulate in animal hosts and zoonotic spillover  continues to occur, particularly in the Democratic Republic of the Congo, the  highest number of mpox cases and incidence of deaths has been documented  among young children (<5 years). Surveillance and diagnostic capacities in these  settings remain suboptimal and have continued to decline in 2026, making the interpretation of available data challenging.

    Among individuals younger than 50 years in the Democratic Republic of the Congo, age-specific mpox incidence appears broadly comparable across age  groups, largely reflecting the underlying age distribution of the population.  However, case fatality among suspected mpox cases in children under five years of age (CFR 3.0%) is higher  than that observed among individuals aged  five to 15 years (CFR 1.9%), and almost twice that observed among  individuals aged 15 years and older (1.7%). Of note, the case fatality ratio in  historically endemic areas of the Democratic Republic of the Congo remains much  higher across all age groups than elsewhere (about 7 to 20-fold higher). This may  arise from specific vulnerabilitiesincluding delayed or limited access to appropriate  health care, compounded by concomitant health risks, such as  malaria, varicella, measles, malnutrition, and complications of mpox such as  dehydration and secondary infections. This higher fatality is particularly observed  in infants and young children, who are largely immunologically naïve. At present,  mortality data from this setting are largely drawn from syndromic surveillance  and multiple studies are underway to better describe the risks  associated with mpox in these settings.

    While targeted vaccination has supported outbreak response, in the  absence of established vaccination programmes against mpox and limited access  to early and appropriate healthcare, children and pregnant women in the affected  settings are likely to continue experiencing elevated health risks from  mpox and MPXV infection.

    The risk of geographic spread associated with non-sexual contact transmission is predominantly local. Available data indicate secondary attack  rates of less than 20% following non-sexual household contact, suggesting that  while children are vulnerable to more severe disease, and outbreaks in schools  have been documented , children generally appear to have a limited role in  driving viral spread. In addition, children have not often been reported as a source  of introduction of mpox in new areas, and their contribution to wider  geographic or cross-border spread remains negligible, compared to spread among adults exposed through sexual contact.

    Most historically endemic areas are rural forested territories, where  there is a risk of insufficient control capacities of outbreak response, particularly  now as countries transition from an acute outbreak response approach to a  longerterm disease control programme. Mpox programmes in these settings have  previously been greatly under-resourced and will increasingly need to rely on  preventive strategies and routine care capacity.

    Overall, in the absence of vaccination programmes for mpox in  historically endemic areas, and resources for national programmes conducting  outbreak response activities, the virus will likely continue to circulate,  disproportionately affecting younger children. 

    The overall public health risk for children in historically endemic areas is,  therefore, assessed as moderate.


All other individuals – global risk

    For individuals outside the above two risk groups, the overall risk of acquiring mpox is lower. While illness in the general population is typically mild  and self-limiting, with most cases requiring only supportive care and no  hospitalization, severe disease and death can also occur, albeit less commonly.  While the risk of severe outcomes is much higher among individuals with  underlying immunocompromising conditions, these persons generally represent a  small proportion of cases reported in recent outbreaks, and thus the majority of  cases with complications or deaths may actually occur in persons without immune  suppression in some settings. As noted above, case fatality in historically endemic  areas of the Democratic Republic of the Congo remains much higher across all age  groups than elsewhere (about 7 to 20-fold higher). More research is needed  to characterise less studied risk factors for severe disease. 

    Some data suggest that adults vaccinated before the cessation of routine smallpox vaccination worldwide , in 1980 or earlier in many  countries, are likely to retain partial cross-protective immunity and present with  lower disease severity.

    While breakthrough cases of mpox have been documented in some older  previously vaccinated persons, epidemiological data indicate that few mpox  deaths have been reported in this group. New cases of mpox with clade Ib  MPXV in various regions have predominantly been associated with sexual contact  in people with a history of travel to outbreak-affected areas who developed  symptoms just prior to or upon return. Spread through sexual networks from  some cases has ultimately led to the establishment of community transmission of  clade Ib MPXV in several countries outside Africa.

    Overall, the spread of clade Ib MPXV in newly affected areas has remained largely confined to groups at risk. Since the start of the global  outbreak in 2022, the general population has not been widely affected by ongoing  circulation of clade IIb MPXV in high income settings, nor has it been implicated in  mpox introduction or establishment in new geographic areas. Secondary  transmission to non-sexual contacts has remained limited. Thus, individuals in this  risk group (“all other individuals”) affected by clade IIb have mainly been  infected through household or occupational contact, characterized by low  secondary attack rates and limited onward transmission. Nonetheless, explosive  outbreaks in West Africa have demonstrated that all age groups can be  significantly affected such that continued vigilance is required for all mpox clade  outbreaks in different settings. Within this broad group which includes most  people, there are also other individuals in settings where there is a higher risk of  onward mpox transmission, such as those in internally displaced person (IDP) and  refugee camps and other congregate, overcrowded settings. Furthermore,  some more vulnerable individuals are considered to face a higher risk of severe  disease and poorer disease outcomes if they fall ill, particularly pregnant  individuals, neonates, and infants. Poor outcomes have been documented among  pregnant individuals and their unborn children, including spontaneous  abortions, missed abortions, still births, congenital mpox and early neonatal  death, with recent studies reporting these adverse outcomes in about half of  pregnant individuals followed up. The healthcare-associated clade Ib mpox outbreak among neonates and infants in Pakistan in early 2026 which  resulted in a CFR higher than 20% also demonstrated that mpox transmission can  lead to severe consequences in highly vulnerable populations. In this instance,  mpox in a neonatal intensive care setting resulted in rapid amplification and disproportionate impact in neonates and infants.

    Public health control measures such as laboratory confirmation, rapid  contact tracing and isolation have generally been sufficient to manage mpox in the  general population, notably in high-income settings. Nonetheless, partner  notification strategies should supplement classic contact-tracing to reach non- disclosed sexual partners. Vaccination has been prioritized for groups at higher  risk of exposure with the intent to prevent and stop transmission. Where vaccines  have, in some settings, been mainly offered to health workers for their individual  protection, this strategy builds confidence and quality of care but cannot be  expected to play a major role in stopping outbreaks.

    In all settings therefore, the general population largely remains  immunologically naïve to mpox, while the risk to health, contribution to  international spread and burden of insufficient response capacities, remains low.  Exceptions to this include where mpox is inadvertently introduced into high-risk  settings, such as newborn and infant care units. 

    The overall public health risk for all other individuals without multiple sexual partners is, therefore, assessed as low.


Overall public health risk

    Mpox continues to pose a public health risk across all WHO regions,  with the likelihood and impact varying by population group, transmission context,  and local response capacity. The African Region will most likely continue observing  sustained community transmission in several countries  outside historically endemic areas, as well as recurrent outbreaks in countries  where zoonotic transmission occurs. While all countries remain at risk of  importation and limited local transmission, recent outbreaks (starting from 2022- 2023) have confirmed observations that sustained transmission and geographic  spread are largely driven by sexual contact in specific population groups and  network dynamics, rather than in the general population, with some notable  exceptions such as health facility-based outbreaks.

    While most countries have established outbreak response mechanisms,  such as early detection and contact tracing that help in controlling  viral spread, the effectiveness of classic contact-tracing for a sexually  transmissible infection remains very limited. Other countries are less prepared and  at a higher risk of missing chains of local transmission, especially where low  index of suspicion, stigma, and discrimination create barriers to access diagnostic testing, clinical care services and implementation of infection prevention and  control measures, and where political and socio-cultural  contexts or other  circumstances preclude timely information-sharing with communities, health  sector partners and timely and complete reporting to WHO.

    While improvements in understanding mpox transmission and risk have  improved since the first mpox public health emergency of international  concern (PHEIC) was declared in 2022, important knowledge gaps remain. These  include uncertainties regarding the role of asymptomatic or pauci-symptomatic  infections, the duration and extent of immunity  following infection or vaccination  (e.g., for immunocompromised individuals), risk factors for severe disease beyond known immunocompromising conditions, and the contribution of zoonotic  spillover and potential human-to-animal transmission. Limited data regarding  animal reservoirs and transmission at the human–animal–environmental interface further limits risk characterization in endemic settings. The lack of  reporting by some countries further limits overall community awareness,  appreciation of risk, and visibility on continuing evolution of the epidemic.

    Several cases and larger outbreaks have been reported in humanitarian emergency settings such as IDP and refugee camps and other congregate,  overcrowded settings, but the risk of spread and modes of transmission in these  settings, including the role of living conditions among other factors, are still poorly  understood. Additionally, transmission between children outside of the  household setting is not fully understood, and its potential to sustain spread of the  virus in the community context has not been quantified.

    In recent years, access to diagnostics, vaccines, and response tools has  improved through coordinated efforts by WHO and partners, and 19 countries  in Africa have implemented vaccination for populations at highest risk.  However, funding constraints, competing public health priorities, and reliance on  limited resources for vaccine supply continue to challenge sustained response  efforts, particularly in low- and middle-income countries. Delays in vaccine  introduction and limited coverage reduce the potential impact of vaccination,  underscoring the importance of prioritization and timely vaccine deployment. In  addition, data on the effectiveness of available therapeutics for mpox remain  limited, particularly in settings reporting the highest burden of disease.

    The detection of a recombinant MPXV strain with genetic elements of  both clade Ib and IIb MPXV warrants continued monitoring. To date, one  additional case has been detected since the last RRA, bringing the cumulative case  count to three. The geographic areas where the recombination event first  occurred remain unknown. While the public health risk associated with this  recombinant strain is currently considered low, ongoing genomic surveillance is  essential given uncertainties related to viral evolution and recombination.

    Overall, MPXV continues to circulate in all WHO regions and pose distinct risks across different population groups and  settings. Sustained  transmission of this still emerging and evolving orthopoxvirus continues, posing  health risks for vulnerable individuals of all ages and in all settings. While  response capacity continued to improve during the second PHEIC, it remains  uneven with suboptimal reporting practices, and highly dependent on dwindling or  non-existent resources as priorities shift. Transition to longer term disease  prevention and control programmes and strategies is still in early stages in most  settings and resources remain extremely limited as interest in mpox response  wanes. Taken together, this context creates additional risk that the gains made  over the past few years may erode. 

    Thus, the overall public health risk at the global level is assessed as moderate.

(...)

Source: 


Link: https://www.who.int/publications/m/item/who-rapid-risk-assessment-mpox--global-v.7

____

Tuesday, July 7, 2026

#Taiwan CDC: The #WMO predicts a strong #ElNiño event this year, which is conducive to spread of #arboviral diseases (July 7 '26)

 


    The latest forecast from the World Meteorological Organization (WMO) indicates that El Niño may intensify further in the coming months, potentially developing into a strong El Niño

    El Niño could further raise global temperatures and alter atmospheric circulation and rainfall patterns, increasing the risk of extreme weather events

    Some regions may face disasters such as short-duration heavy rainfall, torrential rain, and flooding due to more concentrated rainfall, while other regions may experience drought and water shortages

    International research shows that the high temperatures, warm winter, and abnormal rainfall brought about by El Niño may affect the growth and reproduction of disease-carrying mosquitoes, increasing the risk of dengue fever transmission

    Rising temperatures may shorten the growth cycle of disease-carrying mosquitoes, accelerating their reproduction rate; high temperatures may also shorten the time required for the dengue virus to multiply in mosquitoes to become infectious, increasing the chances of virus transmission

    On the other hand, after heavy rainfall, torrential rain, or continuous rainfall, various types of stagnant water environments easily form both indoors and outdoors, increasing the breeding opportunities for disease-carrying mosquitoes. 

    Due to the El Niño phenomenon facilitating dengue fever transmission and the ongoing international outbreaks of dengue fever and other mosquito-borne infectious diseases, coupled with the peak summer travel season, the public is urged to take mosquito prevention measures while traveling abroad and seek medical attention immediately if they experience any symptoms upon returning home, in order to jointly prevent dengue fever.

    Data from the Centers for Disease Control and Prevention (CDC) shows that as of July 6th this year, there have been a total of 83 confirmed dengue fever cases, including 7 local cases, all residing in Kaohsiung City; and 76 imported cases, all from Southeast and South Asian countries, with Indonesia (21 cases) being the most numerous, followed by the Maldives (14 cases) and Vietnam (11 cases). 

    The cumulative number of cases this year is lower than the same period last year (2025) (91 cases). 

    The global dengue fever outbreak remains severe, with over 1.44 million cases reported as of May this year

    The majority of cases are in the Americas, with Brazil having the highest number, followed by Bolivia and Colombia

    Neighboring Asian countries such as Vietnam, Malaysia, Sri Lanka, Cambodia, Bangladesh, and Laos have recently seen an increase in cases, with many exceeding the number from the same period last year, and showing a trend of co-circulation of multiple serotypes (DENV). 

    Given the current rainy season in Southeast Asia, the overall outbreak is expected to remain at its peak. 

    Health authorities are closely monitoring mosquito density in communities and strengthening patrols and prevention efforts in high-risk areas.

    The Centers for Disease Control (CDC) explained that with recent persistent high temperatures and frequent afternoon thunderstorms across Taiwan, post-rain environmental cleanup is crucial for dengue fever prevention. 

    Residents should proactively inspect their homes and surrounding areas, thoroughly removing water-collecting containers such as flowerpot saucers, discarded tires, and other stacked items. 

    Unused containers should be turned upside down or properly stored. A second inspection should be conducted after rain to ensure thorough cleaning and prevent mosquitoes from laying eggs and breeding.

    The Taiwan Centers for Disease Control (CDC) reminds the public that the current climate is suitable for mosquito breeding and activity. 

    When engaging in outdoor activities, the public is advised to wear light-colored long-sleeved clothing and use government-approved mosquito repellents containing effective ingredients such as DEET, Picaridin, or Imamectin (IR-3535). 

    If you experience symptoms resembling dengue fever, such as fever, headache, retro-orbital pain, or muscle and joint pain, please seek medical attention immediately and inform your doctor of your travel history. 

    Medical institutions are also urged to be vigilant, implement TOCC (travel, occupation, contact, and social contact) inquiries, use the dengue NS1 rapid test kit to aid diagnosis, and report cases promptly to facilitate timely prevention and control measures by health authorities. 

    Furthermore, given the ongoing international dengue fever outbreak, if you experience symptoms resembling dengue fever, such as fever, headache, muscle and joint pain, or rash upon arrival in Taiwan, please inform airport quarantine personnel. 

    For information related to dengue fever, please visit the Taiwan Centers for Disease Control website (https://www.cdc.gov.tw) or call the toll-free epidemic prevention hotline 1922 (0800-001922).

Source: 


Link: https://www.cdc.gov.tw/Bulletin/Detail/iheCGS59dCugdGfswWuh5Q?typeid=9

____

Friday, July 3, 2026

#Hantavirus #outbreak linked to cruise #ship travel, Multi-locations (WHO, July 3 '26): End of the Event

 


Situation at a glance

    This is the fifth Disease Outbreak News posting on the Andes hantavirus (ANDV) outbreak linked to the cruise ship M/V Hondius

    The outbreak identification followed the notification to the World Health Organization (WHO) on 2 May 2026 of severe acute respiratory illness cases onboard. 

    Since the previous Disease Outbreak News was published on 28 May 2026, one of the probable cases from Tristan da Cunha, an Overseas Territory of the United Kingdom of Great Britain and Northern Ireland (hereafter referred to as the United Kingdom), was laboratory confirmed

    As of 2 July, a total of 13 cases, including three deaths, have been notified (case fatality ratio 23%). 

    Twelve cases have been laboratory-confirmed for ANDV infection, and one is a probable case. 

    All confirmed cases are among individuals who travelled onboard the M/V Hondius

    Among the ten cases admitted to hospitals, eight have recovered and have been discharged, while two are still undergoing medical treatment

    All identified contacts have completed the 42 day follow-up period by local health authorities in line with WHO guidance. 

    The completion of the contact follow up without detection of additional secondary cases demonstrates effective interruption of transmission and confirms outbreak containment

    This outbreak no longer poses a public health risk and no further related transmission is expected.


Description of the situation

    On 2 May 2026, in accordance with the International Health Regulations (2005) (IHR), WHO received a notification from the National IHR Focal Point (NFP) of the United Kingdom of a cluster of severe acute respiratory illness aboard the Netherlands-flagged cruise ship M/V Hondius, with further details rapidly notified authorities in the Netherlands and South Africa.

    As of 2 July, a total of 13 cases (12 confirmed and one probable case), including three deaths (two confirmed and one probable), have been reported globally linked to the cruise ship. 

    The case fatality ratio for this outbreak to date is 23%. 

    Since the last Disease Outbreak News was published on 28 May 2026, ANDV infection was laboratory confirmed in a probable case in Tristan da Cunha who developed signs and symptoms after disembarkation from the cruise ship. 

    The early detection and isolation of the case prevented further transmission of the virus, but the limited diagnostic capacities on the island delayed the confirmation of the case until a sample was shipped and tested in the United Kingdom. 

    The patient has recovered and has been discharged.

    Among the confirmed cases admitted to hospital, eight have recovered and been discharged, while two, one in South Africa and one in France, continue to be hospitalized

    All 13 cases are among people who travelled on board the M/V Hondius.

(...)

    Nine of the reported cases were males, and four were females. The median age was 65-years-old (IQR 56-70), similar to the median age of the passengers onboard the ship (...). The ages of the three deceased cases were 69, 70 and 79-years-old.

(...)

    Currently available information suggests that infection of initial cases was likely acquired on land prior to embarkation, although the exact source and route of exposure remain undetermined, with subsequent human-to-human transmission occurring aboard the vessel. 

    Investigations remain underway to establish the circumstances and source of the outbreak, including genomic sequencing of ANDV samples from surveillance cases in Chile and Argentina, and will be published as soon as these are available.

    This outbreak was managed through a coordinated international response, which included comprehensive epidemiological investigations, case isolation and clinical management, medical evacuations, laboratory testing, repatriation of passengers and crew from the ship and international contact tracing, as well as quarantine and monitoring measures.

    Contact identification and follow-up of contacts of hantavirus cases linked to the cruise ship has been conducted in 33 countries and overseas territories. 

    This included passengers and crew onboard the ship, contacts of the case on Tristan da Cunha, contacts from two different international flights, healthcare workers and airport crew who assisted cases before the detection of the outbreak. 

    As of 2 July 2026, 317 high-risk contacts have completed quarantine and monitoring by local health authorities in the countries and territories where they were repatriated, evacuated or identified. 

    Some 336 low-risk contacts completed self-monitoring in line with the updated guidance on management of contacts of Andes virus (ANDV) cases from the MV Hondius cruise ship published on 17 May 2026. 


Epidemiology

    Hantavirus disease is a zoonotic viral disease caused by hantaviruses of the genus Orthohantavirus, family Hantaviridae, order Elliovirales, class Bunyaviricetes. More than 20 viral species have been identified within this genus. 

    Human hantavirus infection is primarily acquired through contact with the urine, faeces, or saliva of certain species of (specific) 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.

    Limited human-to-human transmission has currently only been reported for hantavirus pulmonary syndrome (HPS) associated with ANDV virus infection

    ANDV is endemic in South America, with confirmed circulation and human infections reported primarily in Argentina and Chile, and additional cases and related strains identified in Uruguay, southern Brazil, and Paraguay.


Andes virus transmission between humans

    Based on the available information and the existing observations of the current outbreak, limited human-to-human transmission of ANDV is known to occur. 

    However, no large-scale human-to-human outbreaks have been observed historically.[1] 

    ANDV circulates in specific species of rodents in the Americas, and there have been many sporadic cases reported in Argentina and Chile that have not led to onward transmission.[2]  

    Clusters of human cases have been reported in multiple past outbreaks and have been typically associated with close and prolonged interactions, often in shared indoor environments such as households.  

    The largest reported outbreak of ANDV was reported in Argentina in 2018-2019,2 where high viral titres in combination with attendance at large social gatherings or extensive contacts among people were associated with higher transmission.  

    While the available evidence suggests that there are multiple modes of transmission that occur with ANDV, the probability of onward transmission between humans remains low.

    Initial epidemiological investigation and the genomics analysis[3] of the identified cases show that in this outbreak of ANDV infection, human-to-human transmission has occurred on the ship

    While detailed information on the interaction between cases or with a contaminated environment aboard the ship is currently not available, these exact modes of transmission might be elucidated by upcoming results from an in-depth epidemiological investigation, as well as publication of the environmental sampling performed after the disembarkation.  


Response activities operated under the assumption that ANDV transmission:

    ° may have included contact with an infected individual or contaminated surfaces;

    ° and/or through-the-air transmission (via direct deposition of infectious respiratory particles onto exposed facial mucosal surfaces—mouth, nose, or eyes);

    ° and/or airborne transmission (via inhalation of infectious respiratory particles).

    Given the attack rate among the ship passengers, as well as the absence of secondary cases among contacts off the ship, the virus did not exhibit transmission dynamics consistent with highly transmissible airborne pathogens (such as measles).


Public health response

    Authorities from States Parties managing cases and/or contacts, WHO, and partners such as the European Centre for Disease Prevention and Control have coordinated response measures, including:

        ° Ongoing engagement between WHO and the NFPs of countries managing cases and/or contacts ensured timely information sharing and coordination of response actions.

        ° International contact tracing and follow-up of contacts was conducted by local health authorities in line with national arrangements.

        ° WHO requested regular information sharing and periodic updates from States Parties through IHR channels regarding the follow-up of contacts and their health status.

        ° Ongoing epidemiological investigations to define epidemiological links between cases and exposure factors on the ship, as well as to try to understand the potential source of exposure.

    A prospective natural history study designed to improve understanding of Andes virus (ANDV) transmission dynamics, incubation periods, immune responses, viral kinetics, and the determinants of severe disease through harmonised longitudinal follow-up of exposed individuals. The study uses a standardised prospective protocol implemented across 21 participating countries.[4]

    WHO developed and published specific technical guidance documents to support response to the event, including:

        ° Technical guidance on the management of hantavirus onboard ships was shared with States Parties through IHR channels

        ° Technical note for the disembarkation and onward management of passengers and crew in the context of an ANDV-associated cluster;

        ° Management of contacts of Andes Virus (ANDV) cases from the MV Hondius cruise ship

        ° Laboratory testing of Andes virus (Orthohantavirus andesense) infection: Interim guidance

    The NFPs of countries managing cases and/or contacts have been exchanging passenger- and crew-related information.

    WHO provided risk communication coordination and support, ensured timely evidence-based information sharing, activated the coordination mechanisms across the three organizational levels, and supported national authorities in implementing public health measures, including in accordance with IHR provisions.

    WHO convened regular Member State briefings, expert discussions covering key technical, laboratory, clinical care and infection prevention and control (IPC) topics, and global webinars via the EPI-WIN knowledge platform to facilitate experience sharing and coordinate support.

    WHO supported the development of research protocols with national and international partners and planned a hantavirus consultation on medical countermeasures.

    WHO coordinated the distribution of the laboratory testing and reference materials made available by Chile and Argentina, as well as diagnostic protocols and information on available test kits and their performance.


WHO risk assessment

    The ANDV outbreak associated with the MV Hondius cruise ship no longer poses a public health risk and no further related transmission is expected.  

    ANDV remains endemic in South America, and it is associated with hantavirus pulmonary syndrome with substantial case fatality, its transmissibility remains limited, typically requiring close and prolonged exposure, and tends to result in temporally and spatially restricted clusters.

    While the confined maritime environment of this event likely facilitated transmission during the voyage, epidemiological and genomic evidence supports a point source outbreak, originating either from contact with an infected animal or infected person, followed by limited chains of human-to-human secondary transmission, without evidence of sustained transmission.

    The completion of the 42-day follow-up period for all identified contacts without further detection of additional secondary cases demonstrates effective interruption of transmission and confirms outbreak containment

    Additionally, IPC measures continue to be applied for the management of the two cases still hospitalized.


WHO advice

    WHO advises all countries to sustain strong engagement and collaboration to document and learn from this outbreak response, including both successes and operational challenges, and to apply the lessons identified to strengthen preparedness, surveillance including international tracing and follow up of contacts, clinical care, IPC, risk communication, and response capacities for future public health emergencies.

    WHO further encourages the continuation of epidemiological, clinical, laboratory, and ecological studies to better understand the outbreak, its transmission dynamics, risk factors, and determinants of disease severity.

    In areas where hantavirus is endemic, WHO recommends strengthening measures to prevent and control transmission through enhanced surveillance, public awareness, environmental management, reduction of exposure to rodent reservoirs and contaminated environments, and early detection, implementation of IPC measures and management of cases.

    WHO also encourages continued investment in research and development to advance the availability of effective diagnostics, therapeutics, and vaccines, and to improve preparedness and response capabilities for future hantavirus outbreaks.


Further information

    ° 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

    ° 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

    ° World Health Organization. Hantavirus fact sheet. https://www.who.int/news-room/fact-sheets/detail/hantavirus 

    ° 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

    ° World Health Organization. Handbook for management of public health events on board ships. https://www.who.int/publications/i/item/9789241549462

    ° World Health Organization. Guide to Ship Sanitation, 3rd edition https://www.who.int/publications/i/item/9789241546690

    ° World Health Organization. Handbook for management of public health events in air transport, https://www.who.int/publications/i/item/9789241510165

    ° World Health Organization. Guide to hygiene and sanitation in aviation, 3rd edition, https://www.who.int/publications/i/item/9789241547772

    ° 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

    ° 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

    ° 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

    ° World Health Organization. Hantavirus outbreak toolbox. https://www.who.int/emergencies/outbreak-toolkit/disease-outbreak-toolboxes/hantavirus-outbreak-toolbox

    ° 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

    ° 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

    ° 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

    ° World Health Organization Health Emergencies EPI-WIN webinar: Hantavirus in Focus I: what we know and what it means. https://www.who.int/news-room/events/detail/2026/05/20/default-calendar/hantavirus-in-focus-i-what-we-know-and-what-it-means

    ° World Health Organization Health Emergencies EPI-WIN webinar: Hantavirus in Focus II: hantavirus natural history, infection control and clinical management of patients in hospital. https://www.who.int/news-room/events/detail/2026/05/22/default-calendar/who-health-emergencies-epi-win-webinar-hantavirus-in-focus-ii-hantavirus-in-an-international-maritime-setting-natural-history-infection-control-and-clinical-management-of-patients-in-hospital

    ° World Health Organization Health Emergencies EPI-WIN webinar: Hantavirus in focus III: reflections from the IHR Border Health and Points of Entry perspective. https://www.who.int/news-room/events/detail/2026/06/04/default-calendar/who-health-emergencies-epi-win-webinar--hantavirus-in-focus-iiireflections-from-a-border-health-and-point-of-entry-perspective

    ° World Health Organization Health Emergencies EPI-WIN webinar: Hantavirus in focus IV: Infection prevention and control: from isolation to safe discharge and quarantine. https://www.who.int/news-room/events/detail/2026/06/16/default-calendar/who-health-emergencies-epi-win-webinar-hantavirus-in-focus-iv-infection-prevention-and-control-from-isolation-to-safe-discharge-and-quarantine

    ° Pan American Health Organization / World Health Organization. Infection prevention and control of hantavirus infection, including Andes virus disease. Interim regional guidance for suspected or confirmed cases. https://iris.paho.org/items/bc5a7b5a-5a0a-4407-829e-663c762ad615

    ° Pan American Health Organization / World Health Organization. Clinical management of hantavirus infection, including Andes virus disease: Interim regional guidance for suspected or confirmed cases. https://iris.paho.org/items/0fa0dcb1-4395-467d-a431-5408b4eff337    

    ° 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

    ° Epidemiological Alert Hantavirus Pulmonary Syndrome. https://www.paho.org/en/documents/epidemiological-alert-hantavirus-pulmonary-syndrome-americas-region-19-december-2025  

    ° Hantavirus in the Americas: Guidelines for diagnosis, treatment, prevention and control. Available at: https://iris.paho.org/handle/10665.2/40176

    ° Hantavirus Prevention, CDC: https://www.cdc.gov/hantavirus/prevention/?CDC_AAref_Val=https://www.cdc.gov/hantavirus/hps/prevention.html

    ° 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.

    ° US CDC. How to Clean Up After Rodents: https://www.cdc.gov/healthy-pets/rodent-control/clean-up.html

    ° Hantavirus, Washington State Department of Heath, https://doh.wa.gov/sites/default/files/2025-08/420-056-Guideline-Hantavirus.pdf

    ° Hantavirus Infection, MDS Manual, professional version: https://www.msdmanuals.com/professional/infectious-diseases/arboviruses-arenaviridae-and-filoviridae/hantavirus-infection

    ° Hantavirus pulmonary syndrome, https://www.mayoclinic.org/diseases-conditions/hantavirus-pulmonary-syndrome/symptoms-causes/syc-20351838

___

    [1] “Super-Spreaders” and Person-to-Person Transmission of Andes Virus in Argentina | New England Journal of Medicine. https://www.nejm.org/doi/full/10.1056/NEJMoa2009040

    [2] Padula PJ, Edelstein A, Miguel SD, López NM, Rossi CM, Rabinovich RD. Hantavirus pulmonary syndrome outbreak in Argentina: molecular evidence for person-to-person transmission of Andes virus. Virology. 1998 Feb 15;241(2):323-30. doi: 10.1006/viro.1997.8976. PMID: 9499807.  https://pubmed.ncbi.nlm.nih.gov/9499807/

    [3] 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

    [4] Twenty-one countries launch coordinated Andes virus research initiative following hantavirus outbreak. https://www.who.int/news/item/12-06-2026-twenty-one-countries-launch-coordinated-andes-virus-research-initiative-following-hantavirus-outbreak  

__

Citable reference: World Health Organization (2 July 2026). Disease Outbreak News. Hantavirus outbreak linked to cruise ship travel, Multi-locations. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON611

Source: 


Link: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON611

____

Thursday, June 11, 2026

#Andes #hantavirus #outbreak in cruise ship (ECDC, June 11 '26): 1 case reclassified from probable to confirmed

 


    This page is updated as more information becomes available. It was last updated 11 June at 13:05.


    On 2 May 2026, ECDC was notified of a cluster of severe respiratory illness on MV Hondius, a Dutch-flagged cruise ship with passengers and crew from 23 countries, including nine EU/EEA countries. 

    The virus has been identified as Andes hantavirus.

    As of 11 June 2026, 13 cases have been reported in total, including 12 confirmed and one probable case.

    Since the last update on 26 May 2026, one of the previously reported probable cases was reclassified as confirmed following positive laboratory result for hantavirus infection.

    The identification of additional cases after former passengers and crew returned to their home country is possible given the long incubation period of Andes hantavirus and the possibility that some infections occurred on board on the ship. 

    The risk to the EU/EEA general population remains very low.


    ° Confirmed cases12

    ° Probable cases1

    ° Suspected cases0

    ° Number of deaths3

(...)

Source: 


Link: https://www.ecdc.europa.eu/en/infectious-disease-topics/hantavirus-infection/surveillance-and-updates/andes-hantavirus-outbreak

____

Thursday, May 28, 2026

#Hantavirus #outbreak linked to cruise ship #travel, Multi-locations (WHO D.O.N., May 28 '26)

 


Situation at a glance

    -- This is the fourth Disease Outbreak News report on the Andes hantavirus outbreak linked to cruise ship travel, following the notification to the World Health Organization (WHO) on 2 May 2026 of severe respiratory illness cases aboard M/V Hondius, a cruise ship

    -- Since the last DON was published on 13 May, three additional confirmed cases were reported, from Canada, the Netherlands, and Spain

    -- The previously reported inconclusive case from the United States of America was subsequently determined to be negative following further laboratory testing and has been removed from the total case count. 

    -- All cases to date have been passengers or crew members on the ship. 

    -- As of 27 May, a total of 13 cases, including three deaths, have been reported (case fatality ratio 23%). 

    -- Eleven cases have been laboratory-confirmed for Andes virus (ANDV) infection, and two are probable cases

    -- Given the long incubation period of up to six weeks, it is not unexpected that cases continue to be reported until the end of the six weeks since last exposure. 

    -- Through the International Health Regulations (2005) (IHR) channels, National IHR Focal Points (NFPs) have all been informed and are supporting international contact tracing and monitoring 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 Netherlands-flagged cruise ship M/V Hondius.

    -- As of 27 May, a total of 13 cases (eleven confirmed and two probable cases), including three deaths (two confirmed and one probable), have been reported. 

    -- Since the last Disease Outbreak News was published on 13 May, three additional confirmed cases have been reported among passengers or crew members, one each from Canada, the Netherlands, and Spain

    -- The case in Canada developed symptoms during contact follow-up, whereas the cases in the Netherlands and Spain were identified through routine weekly testing of high-risk contacts during follow-up. 

    -- The previously reported inconclusive case from the United States of America was subsequently determined to be negative following further laboratory testing and has been removed from the total count on 15 May. 

    -- All confirmed cases are among people who travelled onboard the M/V Hondius.

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Figure 1. Epidemiological curve of Andes hantavirus cases (n = 13) reported to WHO as of 27 May 2026, 17:00


{Ckick on Image to 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, however, the time between the individual’s visit to Chile and the onset of symptoms exceeds the maximum incubation period. 

    -- Therefore, based on the information currently available, exposure in Chile can be ruled out

    -- 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 near-identical sequence from different cases.[1]

    -- This outbreak is being managed through a coordinated international response

    -- This includes comprehensive epidemiological investigations, case isolation and clinical management, medical evacuations, laboratory testing, and international contact tracing, as well as quarantine and monitoring measures. 

    -- Recommendations are subject to change as new epidemiological and laboratory evidence becomes available, including findings from genetic sequencing.

    -- 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; Ascension, United Kingdom, on 27 April; Praia, Cabo Verde, on 6 May; and Tenerife, Spain, on 10 and 11 May, the remaining 25 crew members and the two healthcare workers from the Netherlands who disembarked in the Netherlands on 18 May and 23 May. Passengers who travelled on flights who may have had exposure to subsequently confirmed cases have been identified and contacted.

    -- High-risk contacts are being quarantined and monitored by local health authorities either in their respective countries or in the ship’s flag country, the Netherlands, or third countries (Table 1). 

    -- As of 22 May 2026, more than 600 contacts, including 53% high-risk and 47% low-risk contacts, have been identified across 32 countries, territories and areas, and are either under close monitoring or self-monitoring in line with the updated guidance on management of contacts of Andes virus (ANDV) cases from the MV Hondius cruise ship   published on 17 May.

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Table 1. Contacts being traced for the Andes hantavirus outbreak on a cruise ship reported to WHO as of 25 May 2026, 17:00.


{Click on Image to Enlarge}

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Epidemiology

    -- Hantavirus disease is a zoonotic viral disease caused by hantaviruses of the genus Orthohantavirus, family Hantaviridae, order Bunyavirales. More than 20 viral species have been identified within this genus.  

    -- Human hantavirus infection is primarily acquired through contact with the urine, faeces, or saliva of certain species of (specific) 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.

    -- Human-to-human transmission has currently only been reported for hantavirus pulmonary syndrome (HPS) associated with Andes virus infection

    -- Andes virus (ANDV) 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.


Andes virus transmission between humans

    -- Based on the available information and the existing observations of the current outbreak, limited human-to-human transmission of ANDV is known to occur

    -- However, no large-scale human-to-human outbreaks have been observed historically,[2] suggesting a low probability of transmission per contact. 

    -- ANDV circulates in specific species of rodents in the Americas, and there have been many sporadic cases reported in Argentina and Chile that have not led to onward transmission.[3] 

    -- Clusters of human cases have been reported in multiple past outbreaks and have been typically associated with close and prolonged interactions, often in shared indoor environments such as households.  

    -- The largest reported outbreak of ANDV was reported in Argentina in 2018-2019,[2] where high viral titres in combination with attendance at large social gatherings or extensive contacts among people were associated with higher transmission.  

    -- While the available evidence suggests that there are multiple modes of transmission that occur with ANDV, the probability of onward transmission between humans remains low.

    -- In this recent outbreak of ANDV infection reported on a cruise ship, human-to-human transmission has also occurred

    -- Considering the ongoing epidemiological studies and environmental sampling after the disembarkation of all passengers from MV Hondius, the exact mode(s) through which human-to-human transmission occurred and their relative contributions are yet to be fully understood

    -- Therefore, at present, WHO is operating under the assumption that ANDV transmission:

        ° may include contact with an infected individual or contaminated surfaces,

        ° and/or through-the-air transmission (via direct deposition of infectious respiratory particles onto exposed facial mucosal surfaces--mouth, nose or eyes)

        ° and/or airborne transmission (via inhalation of infectious respiratory particles).

    -- The virus does not exhibit transmission dynamics consistent with highly transmissible airborne pathogens (such as measles).

    -- This information is up to date as of 27 May 2026. It will be updated as new evidence becomes available and the understanding of transmission evolves.

    -- Using data from the previously documented human-to-human outbreaks in Argentina [2] and the 13 cases so far recorded from the cruise ship outbreak, WHO estimates that the mean incubation period is 22 days, corresponding to a probability of safe release from quarantine of 96% at 42 days, reducing to 91% at 35 days. This reaffirms WHO’s recommendation of 42 days of quarantine for high-risk contacts and self-monitoring for low-risk contacts.

    -- Using case incidence data from the ANDV outbreak associated with the cruise ship, the effective reproduction number (Rt) for this outbreak as of 22 May is estimated to be 0.7, where anything less than 1.0 indicates that the spread of disease is declining. 


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 IHR NFPs of countries managing cases and/or contacts to ensure timely information sharing and coordination of response actions.

        ° International contact tracing and follow up of contacts 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.

        ° 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 onboard ships was shared with States Parties through IHR channels

        ° 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

    -- IHR NFPs of affected countries have been in contact about passenger and crew    information through established IHR channels for those who were on the ship, as well as on planes where a known case was on board. Nearly 1000 communications have occurred through these established channels.

    -- 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, infection prevention and control (IPC), and border health and points of entry domains to facilitate timely experience sharing and coordinated expert support.

    -- WHO has 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 continues to assess the risk for passengers and crew who were onboard the cruise ship as 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.

    -- The risk at the global level is assessed 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.

        ° Human Pulmonary Syndrome caused by hantaviruses in the Americas, including Andes virus, 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 recreational activities. Viral sequencing analyses are also ongoing and are comparing 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 amongst sequenced cases —showing no more than one single nucleotide polymorphisms difference per individual – which 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 well-resourced 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 human-to-human transmission occurs through close and prolonged contact, and can be effectively limited through early detection, isolation of cases, and contact tracing. 


WHO advice

    -- WHO advises States Parties involved in this event to continue coordinated public health management efforts related to the management of cases and contacts associated with the affected ship and flights, as well as in countries where cases and/or contacts have been identified. 

    -- WHO has advised and continues to advise a precautionary approach for management of the outbreak related to the ship, with focus on total containment to minimize the onward risk of transmission to other persons. 

    -- This strategic decision is guided by:

        ° To date, most of the evidence of human-to-human transmission shows it has required prolonged close exposure, although it is possible that some highly infectious individuals could infect others through a lower degree of exposure.

        ° Mode(s) of transmission and which mode is dominant if multiple routes of transmission exist are still uncertain.

        ° Infection is a result of not only exposure, but the setting and duration where exposure has taken place, how infectious the infected person is, and whether personal protective equipment is used.

    -- Although the probability of infection is uncertain, if infection occurs, it can be severe. Currently, there is no specific treatment available and severe disease requires advanced critical care.

    -- There is a relatively low burden of additional infection prevention and control measures.

    -- At this time, WHO does not recommend any changes to routine activities for the general public. People who were on board the affected ship, or who have had close contact with a confirmed case, should follow national health advice. Guidance may be updated as further evidence becomes available.

    -- Recommendations remain dynamic and will be updated as additional epidemiological and laboratory evidence, including genetic sequencing data, becomes available.


Coordination

    -- WHO advises States Parties involved in this event to continue public health coordination related to the management of cases and contacts in countries where they are present or expected to return, as well as of affected conveyances, as applicable and in close coordination with travel and transport authorities, conveyance operators, and other relevant stakeholders at points of entry.

    -- Coordination should ensure the implementation of risk-based, evidence-informed public health measures.


Surveillance

    -- Ongoing epidemiological investigations include detection, investigation, and reporting of suspected cases, as well as contact tracing and monitoring.

    -- As a precautionary measure, high-risk contacts should undergo active monitoring and home or facility quarantine for 42 days following their last exposure.

    -- Current evidence does not support routine laboratory testing or quarantine of low-risk contacts; instead, they should undertake passive self-monitoring and seek medical evaluation if symptoms develop.

    -- Contact tracing and listing should utilize all available information sources, including interviews and relevant conveyance-related documentation (passenger manifests, passenger locator forms, and other relevant activity logs), to ensure completeness.

    -- Early recognition and prompt isolation of suspected cases remain critical to reduce further transmission.


Laboratory

    -- Laboratory testing of suspected cases should be conducted as part of the outbreak response.

    -- Laboratory investigations may include molecular detection, serology, and sequencing to support case confirmation and better understand the outbreak.

    -- Recommendations on laboratory approaches will continue to evolve as new evidence becomes available.


Case management

    -- Early identification, prompt isolation, and clinical evaluation of suspected cases are essential.

    -- When HPS is suspected, patients should be promptly referred for close monitoring and supportive care, including admission to emergency or intensive care settings when needed.

    -- Clinical management is primarily supportive and may include antipyretics, careful fluid management, hemodynamic monitoring, respiratory support, and escalation to advanced interventions for severe cases.

    -- Mechanical ventilation, vasopressors, extracorporeal membrane oxygenation[4] (ECMO), or dialysis may be required for severe disease.

    -- Antibiotics are not routinely indicated for confirmed hantavirus infection, but may be used empirically if bacterial infection cannot be ruled out or is suspected.

    -- Currently, there is no approved specific antiviral treatment for HPS.


Infection Prevention and Control

    -- Suspected or confirmed cases should be isolated in a single, well-ventilated room.

    -- Standard precautions* should be applied at all times for all patients, including hand hygiene, environmental cleaning, and appropriate waste management, outlined in the interim guidance published on 8 May

    -- Transmission-based precautions should be implemented in addition to standard precautions. Health and care workers should use appropriate personal protective equipment, including respirators, eye protection, gowns, and gloves.

    -- Suspected or confirmed cases should be isolated in a single, well-ventilated room.

    -- Transmission-based precautions should be implemented in addition to standard precautions.

    -- Hand hygiene should be performed before and after the use of PPE.

    -- Waste from suspected or confirmed cases should be managed as infectious waste.

    -- Airborne precautions should be applied during aerosol-generating procedures.

    -- The duration of standard and transmission-based precautions should be determined on a case-by-case basis.


Risk Communication and Community Engagement (RCCE)

    -- Communication strategies should prioritize transparent, timely, and culturally appropriate information to affected individuals and the general public.

    -- Risk Communication and Community Engagement (RCCE) efforts should provide clear, consistent, and actionable information, including explanations of the public health measures being implemented.

    -- Messaging should address public concerns regarding transmissibility, severity, and international travel, and clarify recommended actions for different population groups.

    -- Public health awareness should focus on early detection, timely healthcare seeking, and reducing exposure risks, including occupational and environmental exposures.

    -- RCCE activities should be integrated throughout all phases of the response and align with broader public health measures.

    -- Environmental management strategies, including rodent control, should be included as part of prevention efforts.

    -- 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

    -- 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

    -- 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

    -- World Health Organization. Hantavirus fact sheet. https://www.who.int/news-room/fact-sheets/detail/hantavirus 

    -- 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

    -- World Health Organization. Handbook for management of public health events on board ships. https://www.who.int/publications/i/item/9789241549462

    -- World Health Organization. Guide to Ship Sanitation, 3rd edition https://www.who.int/publications/i/item/9789241546690

    -- World Health Organization. Handbook for management of public health events in air transport, https://www.who.int/publications/i/item/9789241510165

    -- World Health Organization. Guide to hygiene and sanitation in aviation, 3rd edition, https://www.who.int/publications/i/item/9789241547772

    -- 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

    -- 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

    -- 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

    -- World Health Organization. Hantavirus outbreak toolbox. https://www.who.int/emergencies/outbreak-toolkit/disease-outbreak-toolboxes/hantavirus-outbreak-toolbox

    -- 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

    -- 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

    -- 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

    -- Pan American Health Organization / World Health Organization. Infection prevention and control of hantavirus infection, including Andes virus disease. Interim regional guidance for suspected or confirmed cases. https://iris.paho.org/items/bc5a7b5a-5a0a-4407-829e-663c762ad615

    -- Pan American Health Organization / World Health Organization. Clinical management of hantavirus infection, including Andes virus disease: Interim regional guidance for suspected or confirmed cases. https://iris.paho.org/items/0fa0dcb1-4395-467d-a431-5408b4eff337    

    -- 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

    -- Epidemiological Alert Hantavirus Pulmonary Syndrome (HPS). https://www.paho.org/en/documents/epidemiological-alert-hantavirus-pulmonary-syndrome-americas-region-19-december-2025  

    -- Hantavirus in the Americas: Guidelines for diagnosis, treatment, prevention and control. Available at: https://iris.paho.org/handle/10665.2/40176

    -- Hantavirus Prevention, CDC: https://www.cdc.gov/hantavirus/prevention/?CDC_AAref_Val=https://www.cdc.gov/hantavirus/hps/prevention.html

    -- 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.

    -- US CDC. How to Clean Up After Rodents: https://www.cdc.gov/healthy-pets/rodent-control/clean-up.html

    -- Hantavirus, Washington State Department of Heath, https://doh.wa.gov/sites/default/files/2025-08/420-056-Guideline-Hantavirus.pdf

    -- Hantavirus Infection, MDS Manual, professional version: https://www.msdmanuals.com/professional/infectious-diseases/arboviruses-arenaviridae-and-filoviridae/hantavirus-infection

    -- 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] “Super-Spreaders” and Person-to-Person Transmission of Andes Virus in Argentina | New England Journal of Medicine. https://www.nejm.org/doi/full/10.1056/NEJMoa2009040

[3] Padula PJ, Edelstein A, Miguel SD, López NM, Rossi CM, Rabinovich RD. Hantavirus pulmonary syndrome outbreak in Argentina: molecular evidence for person-to-person transmission of Andes virus. Virology. 1998 Feb 15;241(2):323-30. doi: 10.1006/viro.1997.8976. PMID: 9499807.  https://pubmed.ncbi.nlm.nih.gov/9499807/

[4] 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. 


Citable reference: World Health Organization (28 May 2026). Disease Outbreak News. Hantavirus outbreak linked to cruise ship travel, Multi-locations. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON604

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Link: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON604

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