#Ensitrelvir for #Covid19 Postexposure #Prophylaxis in #Household Contacts

 

Abstract

Background

Ensitrelvir, an oral inhibitor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 3C-like protease, is approved in Japan for the treatment of mild-to-moderate coronavirus disease 2019 (Covid-19). Previously, no antiviral agents were approved for postexposure prophylaxis in household contacts of patients with Covid-19.

Methods

In this double-blind, randomized, placebo-controlled trial, we randomly assigned persons who were SARS-CoV-2–negative on local diagnostic testing but were household contacts of a patient with Covid-19 (the index patient) to receive either ensitrelvir (375 mg on day 1 and 125 mg daily on days 2 through 5) or placebo within 72 hours after symptom onset in the index patient. The primary end point was Covid-19 (defined by a central laboratory–confirmed positive reverse-transcriptase–polymerase-chain-reaction assay and the presence of ≥1 of 14 prespecified Covid-19 symptoms lasting ≥48 hours) by day 10 in a household contact in the modified intention-to-treat population (all the participants who underwent randomization, had a central laboratory–confirmed negative RT-PCR test for SARS-CoV-2 at baseline, and received at least one dose of the trial drug or placebo).

Results

The modified intention-to-treat population included 1030 participants in the ensitrelvir group and 1011 in the placebo group. The mean age of the participants was 42.4 years; 71.1% had undergone randomization within 48 hours after symptom onset in the index patient, and 37.0% had at least one risk factor for severe Covid-19. The incidence of Covid-19 was lower in the ensitrelvir group than in the placebo group (2.9% vs. 9.0%; risk ratio, 0.33; 95% confidence interval [CI], 0.22 to 0.49; P<0.001). The incidence of adverse events during the trial was similar in the two groups (15.1% in the ensitrelvir group and 15.5% in the placebo group), as was the incidence of serious adverse events (0.2% in each group). No Covid-19–related hospitalizations or deaths were reported.

Conclusions

Ensitrelvir administered to household contacts of a patient with Covid-19 within 72 hours after symptom onset in the index patient was effective in preventing Covid-19 in the contacts. (Funded by Shionogi; SCORPIO-PEP Japan Registry for Clinical Trials number, jRCT2031230124; ClinicalTrials.gov number, NCT05897541.)

Source: 

Link: https://www.nejm.org/doi/full/10.1056/NEJMoa2509306?query=TOC

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#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.

___

    -- 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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#Outbreak of #H9N2 avian #influenza viruses in lesser #rhea in #Peru, June-July 2025

 

Abstract

Avian influenza viruses (AIVs) are endemic in the Americas and responsible for outbreaks in both domestic and wild birds that occasionally spill over into humans. We report the first known outbreak of AIV H9N2 in lesser rhea (Rhea pennata), also known as Darwin’s rhea, in the region of Puno-Peru. The animals in this study lived in an isolated conservation center located in remote highlands above 4,000 m.a.s.l. Between June and July 2025, a total of 46/92 animals were recorded sick, with symptoms including greenish diarrhea (100%), hyporexia (24%), dyspnea (76%), nasal discharge (42%), drowsiness (18%) and isolation from the flock (73%), and 94% later died. Gross pathology exams revealed septicemia characterized by severe hepatitis, pneumonia, tracheitis, enteritis, and encephalitis. Swab and necropsy samples tested positive for Influenza A by PCR and were later identified as H9N2 through whole genome sequencing. We generated complete H9N2 genomes for two individuals. No additional pathogens were found. Phylogenetic analysis across all eight segments revealed that the viruses were low pathogenicity H9N2 AIV strains of North American origin, which indicated this outbreak was a new introduction of the virus into South America. We also performed a comparative mutational analysis and identified multiple mutations previously associated with mammalian host adaptation, increased virulence, increased pathogenicity, and increased virus binding to α2-6 receptors, which may explain the high mortality rates observed despite the supposedly low pathogenicity of the strain. We also identified novel mutations specific to rhea viruses that will need to be experimentally validated. This is the first report of a natural H9N2 systemic infection in an avian host, highlighting a need for increased surveillance efforts for zoonotic influenza viruses with pandemic potential.

Competing Interest Statement

The authors have declared no competing interest.

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.05.08.723762v1

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#UK Health Security Agency #update on the #hantavirus #outbreak (May 13 '26)

 

Latest update

    -- The UK Health Security Agency is paying thanks to everyone who has isolated at Arrowe Park since Sunday evening and to all the staff at the facility and within the wider system for supporting them, commending them for their ‘incredible effort’.  

    -- Today, 6 individuals from Arrowe Park are returning home or to other suitable accommodation to complete their 45 day isolation period. 

    -- Public health and clinical specialists have assessed each individual’s circumstances and following their latest negative PCR test, tailored support packages are being provided to enable people to isolate at home. 

    -- Arrangements for onward travel from Arrowe Park will be managed with appropriate public health protections in place at every stage of the journey. 

    -- All contacts who remain at Arrowe Park remain asymptomatic; they have no symptoms. 

    -- All testing of contacts has been negative for Hantavirus. 

    -- Health protection teams across the UK will continue to monitor and support everyone after they leave the facility, with daily contact throughout the isolation period to ensure appropriate health and wellbeing support.  

    -- Contact tracing, regular monitoring and testing of contacts continues by UKHSA specialist teams. 

    -- Over the coming days, UKHSA will also support relocation of some more contacts who are already isolating, to places where they can do so more easily.   

    -- Medical staff monitoring contacts on Ascension and St Helena have confirmed that one contact, a medic on Ascension island, has developed symptoms. 

    -- Their samples were taken to the UK on 8 May and tested negative. 

    -- Testing is underway to establish whether this is an unrelated illness, with the individual being offered all necessary care. 

    -- We continue to work closely with the FCDO to provide support to the islands of the territories.     

    -- UKHSA continues to work closely with public health teams in devolved administrations and UK Overseas Territories to identify and support those who may have had close contact with cases.  

    -- The risk to the general public remains very low.

    -- Professor Robin May, Chief Scientific Officer at UKHSA, said:

    ''Our teams are working closely with FCDO colleagues and leaders on Ascension island to repatriate British nationals who are currently isolating on the island. Testing is underway to confirm the cause of illness for the person displaying symptoms and we will take all necessary action to support this person and the wider island population whilst continuing to protect public health in England and UK overseas territories.

    ''Once again I must commend those who have cooperated so selflessly with the isolation arrangements at Arrowe Park, and we are pleased that they will now begin to return home to isolate after a very unsettling period for all involved. Thanks also to the NHS and UKHSA colleagues caring for them throughout their time there.

    ''Together this has been an incredible demonstration of international efforts to contain the outbreak. Our priority remains to ensure everyone is safe and well supported, wherever they complete their isolation, and our teams will continue to work closely with all of those affected by this outbreak.

    ''We would ask the media and the public to respect the privacy of the passengers, contacts and their families at what has been a very difficult and distressing time for everyone involved.

Source: 

Link: https://www.gov.uk/government/news/ukhsa-update-on-the-hantavirus-cruise-ship-outbreak

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Emerging and re-emerging vector-borne and other #zoonotic #RNA #viruses: #pathogenesis, #climate-driven dynamics, and strategies for global control

 

Abstract

Vector-borne and other zoonotic RNA viruses provide a significant and growing threat to global health, especially in areas where climate change, urbanization, and population growth facilitate the proliferation of arthropod vectors. This review offers an extensive examination of the biology, epidemiology, and pathogenesis of numerous important viruses, including dengue, Zika, chikungunya, yellow fever, Japanese encephalitis, Crimean–Congo hemorrhagic fever, Nipah, Ebola, and hantaviruses. We underscore how environmental and social factors, particularly increasing temperatures, modified precipitation patterns, and accelerated urbanization, transform vector habitats and spillover dynamics. The article further analyzes host–virus and virus–vector interactions, highlighting mechanisms of immune evasion, neurotropism, and vascular disease. Computational and machine learning models are examined as novel instruments for forecasting outbreaks and developing early warning systems. Finally, a summary of present and prospective control options is provided, covering integrated vector management, Wolbachia-based biological control, vaccinations, and antiviral immunotherapies.

Source: 

Link: https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2026.1755594/full

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#WHO DG's opening #remarks at 44th meeting of PBAC of the Executive Board – 13 May 2026 (#Hantavirus section only, edited)

 

{Excerpt}

Excellencies, Honourable Ministers,

Our Chair, Dr Aspect Maunganidze,

Members of the PBAC, Member States, dear colleagues and friends,

Good morning and welcome once again.

Thank you all for your continuing commitment to the work of WHO through this committee.

Just yesterday I returned from Spain, where I was working with Minister Monica Garcia Gomez and other ministers on the disembarkation and repatriation of passengers and crew aboard the MV Hondius.

As Spain is a PBAC member, and as we are honoured to be joined by Ambassador Martinez, I would like to place on record my thanks to Prime Minister Pedro Sanchez, Minister Gomez, and the government of Spain for their outstanding leadership and partnership over the past week. Muchas gracias.

By the way, I learned a word, “vamos vamos” because they needed to complete on time, and they did, and that was the most frequent word they were using: “vamos vamos”.

Not only did Spain fulfil its legal duty under the International Health Regulations, but it also met its moral duty to show kindness and compassion to the passengers and crew on the ship.

If there’s one thing our divided world needs right now, it’s kindness and compassion.

I would also like to thank the people of Tenerife for their support and solidarity throughout this period, and the European Union for its support.

But of course, many other countries have been involved.

I also thank South Africa, which was the first to confirm hantavirus at the National Institute for Communicable Diseases, after the first patient was evacuated there.

I thank the United Kingdom for notifying WHO and all countries through the IHR.

I thank Cabo Verde for helping with the evacuation of the three symptomatic patients. 

I thank the Netherlands, which has been actively involved through every stage of the outbreak, and has received the evacuees from the ship.

And as Poland is also a PBAC member, I would also like to acknowledge the leadership of the Polish captain of the ship, Captain Jan Dobrogowski.

I have been in regular contact with Captain Jan over the past week, and I would like to thank him and his crew for everything they have done to keep the passengers safe in a very difficult situation.

The ship is now sailing for the Netherlands with the crew, and one of the first messages I received this morning was from Captain Dobrogowski. It said, “Good morning dear Tedros. I am happy to report that so far we don’t have any symptoms onboard.” He has been doing that every morning, by the way.

The passengers have now all been repatriated and will be monitored until the quarantine period ends, on the 21st of June.

But that doesn’t mean the danger is over. In fact, it has entered a new phase as the passengers and crew return home.

    WHO’s advice is that they should be monitored actively at a specified quarantine facility or at home for 42 days from the last exposure, which is the 10th of May, meaning the quarantine period will end on the 21st of June.

    Anyone who becomes symptomatic should be isolated and treated immediately.

    WHO will continue to work closely with experts in all affected countries.

    We ask all countries to report regularly to WHO on the health and well-being of passengers and crew through the International Health Regulations.

I would also like to acknowledge the incredible efforts of all of my WHO colleagues, including Freddy Banza, who boarded the ship in Cabo Verde and stayed there until the disembarkation was complete in Tenerife, monitoring the health of the passengers and crew, and ensuring they were kept safe.

(...)

Source: 

Link: https://www.who.int/news-room/speeches/item/who-director-general-s-opening-remarks-at-the-44th-meeting-of-the-programme--budget-and-administration-committee-of-the-executive-board---13-may-2026

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Weekly Communicable #Disease #Threats #Report, Wk 20, 9–15 May 2026 (ECDC, #Hantavirus section only)

 {Excerpt}

4. Hantavirus disease outbreak on cruise ship - South Atlantic - 2026 

Overview: Update (data cut-off 10.00 a.m.) 

Updates on new reported cases 

-- As of 13 May, and since the previous update on 12 May 2026, no new cases or deaths have been reported. 

-- A repatriated asymptomatic passenger from the United States had inconclusive test results and has been reclassified as such pending additional laboratory tests. 

-- A second US citizen was reported who developed mild symptoms during evacuation and tested negative for the Andes virus. 

Other news 

-- The cruise ship MV Hondius arrived at the port of Granadilla, Tenerife on Sunday 10 May. 

-- Disembarkation of passengers and part of the crew was carried out and completed on 11 May. 

-- The passengers and crew members were transported to the airport and repatriated via evacuation flights throughout 10 and 11 May. 

-- Evacuation was carried out from Tenerife to the following countries: 

    - Spain (14), 

    - France (5), 

    - Canada (4), 

    - the Netherlands (26), 

    - UK (22), 

    - Ireland (2), 

    - Turkey (3), and 

    - the US (17). 

-- Preliminary analysis of genome sequences from some of the positive cases confirmed a high level of genetic similarity between isolates, likely indicating an initial zoonotic spillover event followed by human-to-human transmission. 

-- Further results from genomic sequences are pending. 

Summary 

-- Since the start of the outbreak and as of 12 May 2026, 11 cases (eight confirmed, two probable and one inconclusive) have been reported. 

-- Of these, three have passed away. 

-- Infection prevention measures, including use of personal protective equipment, isolation of symptomatic individuals and social distancing, have been recommended. 

-- Further investigations are ongoing to identify a potential source of exposure. 

Background 

-- On 2 May 2026, the Netherlands informed ECDC about an outbreak of unknown aetiology on a cruise liner under the Dutch flag, the MV Hondius. 

-- The ship had been on a cruise in the Southern Atlantic after departing from Argentina on 1 April and was en route to Cabo Verde. 

-- The cruise followed an itinerary including stops on mainland Antarctica, South Georgia, Nightingale Island, Tristan da Cunha, St Helena, and Ascension Island with Cabo Verde as the next port of call.

-- A total of 149 persons embarked the ship at the beginning of the journey, including 88 passengers and 61 crew. 

-- Passengers and crew represent 23 nationalities, including several EU/EEA countries as well as other countries: Argentina, Australia, Belgium, Canada, France, Germany, Greece, Guatemala, India, Ireland, Japan, Montenegro, the Netherlands, New Zealand, the Philippines, Poland, Portugal, the Russian Federation, Spain, Türkiye, Ukraine, the United Kingdom, and the United States. 

(...)

ECDC assessment: 

-- Person-to-person transmission of ANDV has only been documented following close and prolonged contact. 

-- The current hypothesis is that some passengers were exposed to ANDV while spending time in Argentina (where ANDV is endemic) before embarking the ship, and may subsequently have transmitted the virus to other passengers onboard. 

-- Measures are already implemented onboard to reduce the likelihood of infection for passengers and crew on the cruise ship. 

-- The cruise ship company and the relevant port authorities have also been advised on how to prepare for the management of cases and contacts (e.g. isolation of cases, use of appropriate personal protective equipment, testing, etc). 

-- Even if transmission of ANDV were to happen from passengers evacuated from the ship, ANDV does not transmit easily so it is unlikely that it would cause many cases or a widespread outbreak in the community, if infection prevention and control measures are applied. 

-- In addition, the natural reservoir for ANDV is not present in Europe, so introduction to the rodent population and potential rodent-to-human transmission in Europe is not expected. 

-- The risk to the general population in the EU/EEA from ANDV spreading from this cruise ship outbreak is very low. 

Actions: 

-- ECDC is liaising with Member States, WHO, and the European Commission to collect more information and coordinate actions. 

-- ECDC is supporting response operations through the EUHTF remotely, on site and on the ship in coordination with the affected countries. 

-- ECDC published a Threat Assessment Brief on 6 May 2026, and is providing regular updates on its website.

(...)

Source: 

Link: https://www.ecdc.europa.eu/en/publications-data/communicable-disease-threats-report-9-13-may-2026-week-20

____

#Andes #hantavirus {multi-country} #outbreak, #Update: 13 May 2026 (ECDC, edited)

 

    ECDC was notified on 2 May 2026 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. 

As of 13 May, a total of eleven cases have been reported, including eight confirmed, two probable, and one inconclusive. 

No new cases or deaths have been reported since the previous update. 

The MV Hondius cruise ship arrived at the port of Granadilla, Tenerife, on Sunday 10 May. 

Disembarkation of passengers and part of the crew was completed on 11 May and repatriation of all passengers and crew members to their countries was completed. 

The ship departed from Tenerife on 11 May and is scheduled to arrive in the Netherlands on 17 or 18 May.

The virus has been identified as Andes hantavirus, the only hantavirus that can be transmitted person-to-person, typically requiring close, prolonged contact. 

Measures are already in place on board of the ship to reduce the likelihood of infection among passengers and crew.

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

___

-- Confirmed cases***: 8

-- Probable cases**: 2

-- Suspected cases*: 0

-- Inconclusive cases****: 1

-- Number of deaths: 3

____

{*} A suspected case is a person who:

    ° Has been on or visited the same transport (e.g. ship or plane) where a confirmed or probable Andes hantavirus (ANDV) case was present, 

    - OR - 

    ° Has been in contact with a passenger or crew member of the MV Hondius since 5 April,

    - AND - 

    ° Has a fever (currently or recently),

    ° Plus at least one of the following symptoms: 

        - muscle aches

        - chills

        - headache

        - stomach problems (such as nausea, vomiting, diarrhoea, or abdominal pain)

        - breathing problems (such as cough, shortness of breath, chest pain, or difficulty breathing)

{**} A probable case is a person who:

    ° Has the symptoms listed above, and

    ° Is known to have been in contact with a confirmed or probable ANDV case

{***} A confirmed case is a person who:

    ° Meets the suspected or probable case definition, and

    ° Has a laboratory test that confirms ANDV infection (PCR or antibody test)

{****} An inconclusive case means awaiting further laboratory investigations.

Non-case

° A non-case is a person who was initially considered a suspected or probable case, but tests negative for ANDV using laboratory tests (PCR or antibody test).

Source: 

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

____

Pre-existing systemic and #nasal #antibodies against avian #H5 #influenza A viruses vary according to #childhood imprinting

 

Abstract

Avian influenza A viruses (IAV) pose a constant pandemic threat, with the recent 2.3.4.4b clade of the H5 subtype causing high pathogenicity and spreading across animal species and geographic locations. Understanding human pre-existing immunity to avian H5 IAV can inform on population susceptibility, a critical aspect of pandemic preparedness. To that end, we analysed the IAV HA-specific antibodies across individuals born between 1928-1999 with different early life exposures to IAV subtypes. Individuals born prior to 1957 had the highest pre-existing serum antibodies to group 1 HA antigens, including the 2.3.4.4b H5 and a group 1 HA stem antigen. These birth-year-specific patterns were not reflected in the limited pre-existing serum neutralising antibodies detectable against a 2.3.4.4b H5 IAV or in H5-specific memory B cell populations. They were however evident in pre-existing nasal IgG and IgA titres to H5, which were greater in individuals born prior to 1957. Our findings demonstrate that the immunological biases afforded by early life exposure extend to antibodies detected in the nasal mucosa, the site of IAV replication.

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.05.08.723737v1

____

G4 #Eurasian avian-like #H1N1 swine #influenza viruses exhibit enhanced #pathogenicity potential in mice and #pigs

 

Abstract

Currently circulating swine influenza viruses (SIVs) mainly include H1N1, H1N2, and H3N2 subtypes. In this study, two G4 genotype Eurasian avian-like (EA) H1N1 SIVs were isolated from 556 samples collected between 2023 and 2026. A systematic analysis was conducted on the two EA H1N1 isolates (FYD30 and YZF69) to assess their pandemic potential. The hemagglutinin (HA) proteins of both H1N1 viruses possessed residues 225E and 228S, indicating enhanced affinity for human-like alpha-2,6-linked sialic acid receptors, which was confirmed by receptor-binding assays. Polymerase activity tests demonstrated that the two SIVs exhibited significantly higher activity in mammalian cells, relative to avian cells, which is consistent with the efficient replication in mammalian cells. Challenge experiments revealed that both H1N1 caused significant pathogenicity in mice and pigs, with YZF69 exhibited higher virulence than FYD30. The higher virulence of YZF69 may be attributed to its molecular features, including the NP Q357K mutation, and an additional glycosylation site in HA. In conclusion, currently circulating EA H1N1 SIVs have acquired key molecular signatures of mammalian adaptation, exhibit enhanced virulence in mammals, and continue to undergo extensive reassortment driven by international swine trade. These findings highlight the potential pandemic risk of SIVs and underscore the urgent need for strengthened surveillance.

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.05.12.724537v1

____

The #Coinfection of #Bartonella spp. and #Hantavirus in Wild #Rodent and #Shrew Species in Eastern #China

 

Abstract

Background:

Bartonella spp. are Gram-negative bacteria that cause diseases including endocarditis, lymphadenopathy, and neuroretinitis. Hantavirus (HV), belonging to the family Hantaviridae, induces illnesses such as hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome. Both pathogens exhibit host specificity—defined as a preference or restriction to specific host species or ranges. Rodents and shrews are primary hosts for these pathogens, and their high coinfection rates often indicate elevated risk of human exposure. To our knowledge, however, data on Bartonella spp.–HV coinfection in rodents and shrews from Eastern China remain limited.

Materials and Methods:

Between 2020 and 2023, rodents (n = 311) and shrews (n = 16) were investigated for coinfection with Bartonella spp. and HV in Qingdao, eastern China. Nested Polymerase Chain Reaction (PCR) was used for the detection of RNA-dependent RNA polymerase (RdRp) gene of HV and the Internal Transcribed Spacer, citrate synthase (gltA) and RNA polymerase beta subunit (rpoB) genes of Bartonella spp.

Results:

The overall infection rates of Bartonella spp., HV, and coinfection were 21.4%, 6.7%, and 4.0%, respectively. The highest rates were observed in Apodemus agrarius (53.8%, 21.3%, and 15.0%). Coinfection rates differed significantly by species (p < 0.05), with A. agrarius exhibiting the highest rate (15.0%). Notably, the coinfection rate was significantly higher in male (28.9%) than female A. agrarius (7.1%) (p < 0.05).

Conclusions:

This study confirms the coinfection of Bartonella spp. and HV in rodents in the eastern region of China. Enhanced monitoring of rodent and shrew densities, as well as their carried pathogens, is essential. Additionally, timely screening, diagnosis, and treatment should be conducted for high-risk populations in the region to reduce the incidence of related zoonoses.

Source: 

Link: https://journals.sagepub.com/doi/10.1177/15303667261448824

____