Computational #design of an ultrapotent #deltacoronavirus miniprotein #inhibitor

 

Significance

Multiple porcine deltacoronavirus (PDCoV) spillovers occurred in Haiti and there are currently no vaccines or therapeutics approved for use in humans. We computationally designed PDCoV miniprotein inhibitors and identified one (MB11) that potently and broadly neutralizes distantly related delta-coronaviruses. MB11 is resistant to multiple biochemical stresses, an ideal property for easy storage and delivery. These data pave the way for developing therapeutics to prepare for possible future PDCoV outbreaks.

Abstract

Multiple spillovers of porcine deltacoronavirus (PDCoV) into humans in Haiti highlight its zoonotic potential and the need for targeted interventions. No approved vaccines or therapeutics are available for use in humans against any DCoVs. Here, we report the de novo design of PDCoV miniprotein inhibitors (aka minibinders, MBs) and show that one of them, MB11, binds with picomolar affinity to the PDCoV receptor-binding domain (RBD). MB11 potently inhibits PDCoV, outcompeting monoclonal antibodies, and cross-reacts with and broadly neutralizes a panel of distantly related DCoVs. We determined a cryoelectron microscopy structure of MB11 bound to the PDCoV RBD which reveals the molecular basis of broad DCoV neutralization through interference with host receptor engagement. Deep mutational scanning of the PDCoV RBD reveals that MB11 has a high barrier to viral escape with only few mutations mediating escape without dampening APN receptor binding. MB11 resists stringent biochemical stresses, including high temperature, low pH, and proteolysis, which may enable delivery to various tissues for viral inhibition. This work delineates a prime candidate for clinical evaluation against PDCoV infection and for pandemic preparedness.

Source: 

Link: https://www.pnas.org/doi/abs/10.1073/pnas.2533456123?af=R

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Avian #Influenza #Report - April 26 – May 2 '26 (Wk 18) (HK CHP, May 5, 2026): 1 new #human #H5N1 case in #Bangladesh; 1 new #H9N2 case in #China

 

{Excerpt}

(...)

{H5N1}

-- Date of report: Late April 2026 

-- Country: Bangladesh 

-- Province / Region: Chattogram Division 

-- District / City: ...

-- Sex: ...

-- Age: Child 

-- Condition at time of reporting: Deceased 

-- Subtype of virus: H5N1

(...)

{H9N2}

1) Guangxi Zhuang Autonomous Region

-- A one-year-old boy with onset on April 12, 2026. 

(...)

Source: 

Link: https://www.chp.gov.hk/files/pdf/2026_avian_influenza_report_vol22_wk18.pdf

____

#Update: First locally acquired #human case of #H7N7 #influenza A was detected in #Taiwan (CDC, May 5 '26)

 

-- The Taiwan Centers for Disease Control (CDC) announced today (April 5) that regarding the first locally transmitted case of H7N7 novel influenza A reported on April 2 involving a poultry farmer, the CDC has completed gene sequence comparison and analysis. 

-- Furthermore, after joint assessment of the overall impact by agricultural and health authorities, the public health risk rating for Taiwan is "low risk."

-- The CDC pointed out that the patient was discharged from isolation on April 3, and the 33 identified contacts completed health monitoring on April 6, with no confirmed cases of novel influenza A. 

-- There is no risk of the outbreak expanding. 

-- This case was discovered due to the high level of vigilance of the hospital physician, who reported the case based on clinical symptoms, contact history, and preliminary test results, leading to confirmation of novel influenza A. 

-- Therefore, the CDC will award the reporting physician a NT$10,000 reporting bonus in accordance with Article 5, Paragraph 1, Item 1 of the Infectious Disease Prevention and Control Reward Regulations.

-- The CDC explained that this case was investigated and controlled through cooperation between health and agricultural authorities, based on the national integrated epidemic prevention action. 

-- Gene sequence comparison of the virus showed that it was most similar to the virus strain isolated from wild birds in Japan and South Korea in 2024, and all gene fragments originated from the Eurasian low pathogenic avian influenza virus gene pool, indicating that the virus is highly related to the virus circulating in wild bird populations. 

-- Further analysis showed that the virus's PB2 gene carries the E627K mutation (PB2 E627K). 

-- According to existing research, this mutation may enhance the virus's replication ability in mammalian cells. 

-- However, since it cannot be ruled out that this site is a mutation produced in humans after infection, and no virus with the same characteristics has been found in Taiwan recently, nor have any drug resistance-related mutations been detected, the current assessment is that the risk to the public is low. 

-- In addition, agricultural authorities actively completed sampling at other poultry farms of the case before the Qingming Festival holiday, expanded sampling at five poultry farms near the case, and cooperated with the Wild Bird Association to collect 92 wild bird specimens from the surrounding area, all of which did not detect avian influenza-related viruses.

-- The Taiwan Centers for Disease Control (CDC) stated that, based on the spirit of national epidemic prevention unity, the CDC also launched a joint risk assessment team with agricultural and health authorities on April 1st to conduct a domestic risk assessment of the H7 subtype viruses (including H7N7, H7N2, H7N3, and H7N4). 

-- This risk assessment primarily referenced the framework of the US CDC's Influenza Risk Assessment Tool (IRAT). 

-- Team members collected supporting data and scores for ten risk factors and corresponding assessment questions, followed by a comprehensive evaluation. 

-- The results showed that the overall risk of the four H7 subtype viruses was low. 

-- While the possibility of sporadic local cases in the future cannot be ruled out, direct and indirect contact with animals remains the main transmission route. 

-- No evidence of sustained human-to-human transmission has been found, and the possibility of further community spread is extremely low.

-- In response to the detection of the key PB2 E627K variant in the first domestic H7N7 human infection case and concerns about the lack of herd immunity among the Taiwanese public to the H7 subtype of avian influenza, the Taiwan Centers for Disease Control (CDC) is not only closely monitoring genomic evolution but also convening expert meetings to focus on assessing the risk of cross-species transmission to ensure the disease prevention system can effectively address potential public health threats. 

-- Furthermore, the CDC is continuously strengthening the One Health inter-ministerial surveillance mechanism, maintaining surveillance in poultry farms and wild animals, closely monitoring genomic evolution, raising clinicians' awareness of the need for testing cases of pneumonia of unknown cause with a history of contact with poultry or livestock, and enhancing related prevention and control measures such as antiviral drugs.

-- In its global risk assessment of the H7 subtype of avian influenza, the World Health Organization (WHO) stated that the global H7 subtype of avian influenza is mainly prevalent in wild and domestic poultry populations. 

-- Although there have been occasional cases of human infection through contact with infected animals in the past, these cases have mostly presented with mild symptoms such as conjunctivitis or influenza-like illness. 

-- The Netherlands reported one death case in 2003. 

-- Given the potential impact on public health, close monitoring of human infections of this virus is crucial. 

-- Based on the current lack of evidence of sustained human-to-human transmission or community spread, the WHO assesses the threat to public health as remaining low. 

-- While sporadic human cases cannot be ruled out, the probability of human-to-human transmission is extremely low.

Source: 

Link: https://www.cdc.gov.tw/Bulletin/Detail/N1P8C-k3KudXQW2VAkp9UQ?typeid=9

____

#Hantavirus #cluster linked to cruise #ship #travel, Multi-country (WHO D.O.N., May 5 '26)

 

Situation at a glance

-- On 2 May 2026, a cluster of passengers with severe respiratory illness aboard a cruise ship was reported to the World Health Organization. 

-- The ship is carrying 147 passengers and crew. 

-- As of 4 May 2026, seven cases (two laboratory confirmed cases of hantavirus and five suspected cases) have been identified, including three deaths, one critically ill patient and three individuals reporting mild symptoms. 

-- Illness onset occurred between 6 and 28 April 2026 and was characterized by fever, gastrointestinal symptoms, rapid progression to pneumonia, acute respiratory distress syndrome and shock. 

-- Further investigations are ongoing. 

-- The outbreak is being managed through coordinated international response, and includes: 

- in-depth investigations, 

- case isolation and care, 

- medical evacuation and 

- laboratory investigations. 

-- Human hantavirus infection is primarily acquired through contact with the urine, faeces, or saliva of infected rodents. 

-- It is a rare but severe disease that can be deadly. 

-- Although uncommon, limited human to human transmission has been reported in previous outbreaks of Andes virus (a specific species of hantavirus). 

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

Description of the situation

-- On 2 May 2026, WHO received notification from the National International Health Regulations (2005) (IHR) Focal Point of the United Kingdom of Great Britain and Northern Ireland (hereafter referred to as the United Kingdom) regarding a cluster of severe acute respiratory illness, including two deaths and one critically ill passenger, aboard a Dutch-flagged cruise ship. 

-- On 2 May 2026, laboratory testing conducted in South Africa confirmed hantavirus infection in one patient who is critically ill and in intensive care. 

-- On 3 May, one additional death was reported. 

-- A further three suspected cases remain on board. 

-- As of 4 May, a total of seven (two confirmed and five suspected) cases, including three deaths, have been reported.

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

-- The extent of passenger contact with local wildlife during the voyage, or prior to boarding in Ushuaia remains undetermined. 

-- The vessel carries a total of 147 individuals, including 88 passengers and 59 crew members. 

-- Onboard passengers and crew represent 23 nationalities.  

-- As of 4 May 2026, the vessel is moored off the coast of Cabo Verde.

Summary of cases:

-- Case 1: 

- An adult male developed symptoms of fever, headache, and mild diarrhoea on 6 April 2026 while on board the ship. 

- By 11 April, the case developed respiratory distress and died on board on the same day. 

- No microbiological tests were performed. 

- The body of the passenger was removed from the vessel to Saint Helena (a British Overseas Territory) on 24 April.

-- Case 2: 

- An adult female, who was a close contact of case 1, went ashore at Saint Helena on 24 April 2026 with gastrointestinal symptoms. 

- She subsequently deteriorated during a flight to Johannesburg, South Africa, on 25 April. 

- She later died upon arrival at the emergency department on 26 April. 

- On 4 May, the case was subsequently confirmed by PCR with hantavirus infection. 

- Contact tracing for passengers on the flight has been initiated.

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

-- Case 3: 

- An adult male presented to the ship's doctor on 24 April 2026 with febrile illness, shortness of breath and signs of pneumonia. 

- On 26 April, his condition worsened. 

- He was medically evacuated from Ascension to South Africa on 27 April, where he is currently hospitalised in an Intensive Care Unit (ICU). 

- Laboratory testing on an extensive respiratory pathogen panel was negative; however, polymerase chain reaction (PCR) testing confirmed hantavirus infection on 2 May 2026. 

- Serology, sequencing and metagenomics are ongoing.

-- Case 4: 

- An adult female, with presentation of pneumonia, died on 2 May 2026. 

- The onset of symptoms was on 28 April, with fever and a general feeling of being unwell.

-- Three suspected cases have reported high fever and/or gastrointestinal symptoms and remain on board. 

- Medical teams in Cabo Verde are evaluating the patients and collecting additional specimens for testing.

Public health response

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

- Ongoing engagement between WHO and the National IHR Focal Points of Cabo Verde, the Netherlands, South Africa, Spain and the United Kingdom, to ensure timely information sharing and coordination of response actions.

- WHO shared information about the events with National IHR Focal Points globally.

- Passengers onboard have been advised to practice maximal physical distancing and remain in their cabins where possible.

- Epidemiological investigations are underway to determine the source of exposure.

- The National IHR Focal Point of Argentina shared the passenger and crew lists with the National IHR Focal Points of the respective countries, according to each person’s nationality.

- In line with the Working Arrangement between the WHO Emergency Medical Team (EMT) Secretariat and the EU Emergency Response Coordination Centre (ERCC), the EMT Secretariat has launched formal discussions to support the clinical management and medical evacuation of symptomatic passengers.

- Logistic support has been provided, including sample collection items.

- Laboratory testing and confirmation of hantavirus infection have been conducted at the National Institute for Communicable Diseases (NICD) of South Africa. Serology, sequencing and metagenomics are ongoing.

- Additional laboratory samples from symptomatic passengers are being sent, with WHO support, to the Institut Pasteur de Dakar, Senegal, for testing.

- WHO has activated three-level coordination and is supporting national authorities in implementing risk-based, evidence-informed public health measures in accordance with the provisions of the IHR and related WHO technical guidance documents.

WHO risk assessment

-- Hantavirus cardiopulmonary syndrome (HCPS), also known as hantavirus pulmonary syndrome (HPS), is a zoonotic, viral respiratory disease caused by hantaviruses of the genus Orthohantavirus, family Hantaviridae, order Bunyavirales. 

-- More than 20 viral species have been identified within this genus. 

-- In the Americas, Sin Nombre virus is the predominant cause of HPS in North America, while Orthohantavirus andesense is responsible for most cases in South America.

-- Human Hantavirus infection is primarily acquired through contact with the urine, faeces, or saliva of infected rodents or by touching contaminated surfaces. 

-- Exposure typically occurs during activities such as cleaning buildings with rodent infestations, though it may also occur during routine activities in heavily infested areas. 

-- Human cases are most commonly reported in rural settings, such as forests, fields, and farms, where rodents are present, and opportunities for exposure are greater. 

-- HPS is characterized by headache, dizziness, chills, fever, myalgia, and gastrointestinal problems, such as nausea, vomiting, diarrhoea, and abdominal pain, followed by sudden onset of respiratory distress and hypotension. 

-- Symptoms of HPS typically occur from 2-4 weeks after initial exposure to the virus. However, symptoms may appear as early as one week and as late as eight weeks following exposure.

-- Hantavirus infections are relatively uncommon globally.  

-- In 2025 (as of epidemiological week 47), in the Region of the Americas, eight countries reported 229 cases and 59 deaths with a CFR of 25.7%. [1] 

-- In the European Region, 1885 hantavirus infection reported in 2023 (0.4 per 100,000), marking the lowest rate observed between 2019 and 2023.[2] 

-- In East Asia, particularly China and the Republic of Korea, Hantavirus haemorrhagic fever with renal syndrome (HFRS) continues to account for many thousands of cases annually, although incidence has declined in recent decades.

-- Hantavirus infections are associated with a case fatality rate of <1–15% in Asia and Europe and up to 50% in the Americas. 

-- While there are no specific treatment nor vaccines for hantavirus infections, early supportive care and immediate referral to a facility with a complete ICU can improve survival.

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

-- Although uncommon, limited human‑to‑human transmission of HPS due to Andes virus has been reported in community settings involving close and prolonged contact. 

-- Secondary infections among healthcare workers have been previously documented in healthcare facilities, though remain rare.

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

WHO advice

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

-- In the context of the current outbreak, passengers and crew members should practice frequent hand hygiene, remain vigilant of Hantavirus symptoms and undertake active symptom monitoring for 45 days.  

-- Crew must ensure adequate environmental cleaning (avoiding dry sweeping) and ventilation in the ship. 

-- Passengers and crew members experiencing symptoms should inform medical professionals on board and self-isolate. 

-- If respiratory symptoms are present to practice respiratory etiquette and wear a medical mask.

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

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

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

-- In healthcare environments, standard precautions* should be applied for all patients, including hand hygiene and safe handling of blood and body fluids. 

-- In addition to standard precautions, transmission-based precautions should be implemented for management of suspect or confirmed cases. 

-- Standard precautions combined with droplet precautions during close contact are considered sufficient. 

-- Routine airborne precautions are not typically required, except during aerosol‑generating procedures. [3]

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

-- Initial management should include supportive care with antipyretics and analgesics as needed. 

-- For confirmed hantavirus, antibiotics are not routinely indicated. 

-- However, before a definitive diagnosis is established (and bacterial infection is a diagnostic possibility), or if superadded bacterial infection is suspected, empiric broad-spectrum antibiotics may be appropriate. 

-- Clinical management relies primarily on careful fluid administration, hemodynamic monitoring, and respiratory support. 

-- Given the rapid progression of HCPS, close monitoring and early transfer to ICU are critical for more severe cases. 

-- Mechanical ventilation, meticulous volume control, and vasopressors may be required. 

-- For severe cardiopulmonary insufficiency, extracorporeal mechanical oxygenation may be lifesaving. In severe cases of renal dysfunction, dialysis may be required.

-- Although ribavirin has shown efficacy against hantavirus haemorrhagic fever with renal syndrome, it has not demonstrated effectiveness for HCPS and is not licensed for either treatment or prophylaxis of hantavirus pulmonary syndrome. 

-- At present, there is no specific antiviral treatment approved for HCPS.

-- Public health awareness efforts should focus on improving early detection, ensuring timely treatment, and reducing exposure risks. 

-- Preventive measures should address occupational and ecotourism-related exposures, emphasize standard and transmission-based infection prevention and control practices, and include rodent control strategies. 

-- Most routine tourism activities carry little or no risk of exposure to rodents or their excreta.

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

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

-- Risk communication and community engagement interventions should prioritize transparent, timely, and culturally appropriate communication to raise awareness of hantavirus transmission risks—particularly exposure to rodent excreta in endemic areas—and promote practical preventive behaviours such as safe food storage, avoiding contact with rodents, wet-cleaning methods (no dry sweeping), and proper ventilation. 

-- Community engagement strategies should involve local leaders and workers in high-risk occupations to co-develop and disseminate tailored messages, address misinformation, and reinforce early care seeking.

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

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

___

{*} 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. Hantavirus fact sheet. https://www.who.int/news-room/fact-sheets/detail/hantavirus

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

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

-- Pan American Health Organization / World Health Organization (PAHO/WHO). 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.

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

-- 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

-- 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. Vector surveillance and control at ports, airports and ground crossings https://www.who.int/publications/i/item/9789241549592

-- Standard precautions for the prevention and control of infections: aide-memoire

___

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

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

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

__

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

Source: 

Link: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON599

____

Three dead in suspected #hantavirus infection #outbreak on cruise #ship: #WHO (UN News Centre, May 4 '26)

Three people have died and three others are ill following suspected cases of hantavirus infection on a cruise ship in the Atlantic, the World Health Organization (WHO) said on Sunday.

WHO is supporting the response, noting that one case of the rodent-borne disease has been confirmed so far and there are five additional suspected cases.  Detailed investigations are ongoing, including further laboratory testing.

Of the six people affected, three have died and one is currently in intensive care in South Africa. 

“Medical care and support are being provided to passengers and crew. Sequencing of the virus is also ongoing,” WHO said in a statement posted on X.

Rapid action critical

In a separate tweet, WHO chief Tedros Adhanom Ghebreyesus said the agency “is facilitating medical evacuation of two symptomatic passengers, conducting a full risk assessment, and supporting affected people onboard.”

He stressed that “rapid, coordinated action is critical to contain risks and protect public health.”

Hantavirus infection is a rare disease linked to infected rodent droppings or urine that can cause life-threatening respiratory problems. 

The cruise liner—operated by a Dutch company—left Argentina three weeks ago and was ultimately heading for the Canary Islands but is currently sitting off the coast of Cabo Verde in West Africa, according to media reports.

WHO has also informed its National Focal Points in accordance with the International Health Regulations, the 2005 treaty that outlines countries' rights and obligations in managing public health risks, events and emergencies that could potentially cross borders.

A public notice also will be issued.

Source: 

Link: https://news.un.org/en/story/2026/05/1167431

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#Replication Efficiency of Contemporary Highly Pathogenic Avian #Influenza #H5N1 Virus Isolates in #Human #Nasal Epithelium Model

 

Abstract

Replication of influenza A virus in human nasal epithelium affects transmissibility and disease. We compared virus replication and immune responses in human nasal epithelium infected with seasonal and highly pathogenic avian influenza A(H5N1) viruses. Contemporary H5N1 viruses replicated better than the historical isolate; however, interferon response to B3.13 genotype viruses was dampened.

Source: 

Link: https://wwwnc.cdc.gov/eid/article/32/5/26-0053_article

____

#Human #infections with avian #influenza #H5 viruses with potential #pandemic #risk: 1997–2025

 

ABSTRACT

Highly pathogenic avian influenza (HPAI) A(H5) viruses have caused sporadic human infections since 1997, with recent detections in the Americas and Asia. However, the evolutionary dynamics of different HPAI A(H5) viruses at the animal–human interface, along with their associated disease severity, propensity for animal-to-human (zoonotic) spillover, and human-to-human transmission potential, remain unclear. Here, we combine available genetic and epidemiological data with mechanistic models to better understand the global spread of HPAI A(H5) viruses that spilled over to humans in 1997–2025. Analysis of 7445 subsampled hemagglutinin gene sequences revealed frequent regional succession of HPAI A(H5) virus clades that varied by geographic location. The 1104 reported human HPAI A(H5) cases exhibited subtype- and clade-specific heterogeneity in age, gender, and exposure sources (p < 0.001). After adjusting for under-reporting, we estimated case-fatality risk to be low for HPAI A(H5N1) clade 2.3.4.4b (0.7%, 95%CI: 0.02%–3.9%) and for A(H5N6) clades 2.3.4x (0%, 0%–1.1%) and 2.3.4.4b (1.6%, 0.7%–3.2%), compared with other A(H5) clades (range: 4.7%–15.0%). We also show that, while the transmissibility of HPAI A(H5) viruses between humans remains very low to date (mean Rt: 0.10–0.23), zoonotic transmission has increased with the emergence of bovine-origin clade 2.3.4.4b (incidence: 7.85 per million people per year), relative to other avian-origin A(H5) clades (range: 1.54–5.04 per million people per year). Although other factors such as exposure sources, routes of transmission, immune function, underlying medical conditions, and clinical management can influence outcomes of case-patients, these findings highlight the ongoing pandemic threat posed by HPAI A(H5) viruses and the need for ongoing comprehensive surveillance, genotypic and phenotypic characterization, and preparedness.

Source: 

Link: https://academic.oup.com/nsr/article/13/7/nwaf471/8317928

____

Mechanistic #modelling of highly pathogenic avian #influenza: A scoping #review revealing critical gaps in cross-species #transmission models

 

Abstract

Background

Highly pathogenic avian influenza (HPAI) viruses, particularly subtypes such as H5N1 and H7N9, have caused widespread outbreaks in wild birds, poultry, livestock and occasionally humans, raising concerns about cross-species transmission and pandemic potential. Effective control and surveillance strategies require a thorough understanding of HPAI transmission dynamics, which can be supported by mathematical modelling.

Objective

This scoping review aimed to identify mechanistic models used to study HPAI transmission. Specifically, we sought to categorize model types, describe their application contexts (e.g., wild birds, poultry, livestock, and humans), and highlight modelling gaps relevant to understanding and mitigating the risks of HPAI spread.

Methods

Following PRISMA guidelines and the PRISMA extension for scoping reviews (PRISMA-ScR), we conducted systematic searches of PubMed and Web of Science to identify peer-reviewed studies employing deterministic and stochastic models to analyze HPAI transmission. Eligible articles published between January 2023 and June 2025 were screened and grouped by model structure, host populations, transmission pathways, and modelling objectives.

Results

After screening, 30 studies published after 2023 were included in this scoping review. Compartmental models were the most common (26 studies), with 16 deterministic and 10 stochastic approaches. These models were primarily used to describe transmission among wild birds, poultry, livestock, and humans and to evaluate interventions such as culling, vaccination, and movement restrictions. Agent-based models (2 studies) captured individual-level interactions and spatial heterogeneity, while network models (2 studies) represented contact structures and transmission pathways between farms or species.

Conclusions

Currently, mechanistic modelling of HPAI is dominated by compartmental approaches, including both deterministic and stochastic formulations, whereas agent-based and network models remain relatively underused. Although most studies focus on transmission in wild birds and poultry, and in some cases spillover infections to humans, few explicitly examine infection dynamics in livestock or in transmission between livestock and humans, despite the importance of livestock (e.g., cattle) as potential intermediaries in human infection. Key gaps persist in the integration of empirical data, representation of multi-host interactions, and evaluation of realistic intervention strategies. Addressing these limitations is essential to improve predictive accuracy and to strengthen the role of modelling in informing HPAI surveillance and control.

Source: 

Link: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0347929

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#Influenza at human-animal interface - Summary & #risk #assessment (23 Jan. - 31 March 2026) (WHO, Apr. 29 '26): #H5N1, #H9N2, #H10N3, #H1N1v, #H3N2v cases reported

 

New human cases {2}: 

-- From 23 January to 31 March 2026, based on reporting date, detections of  influenza A(H5N1) in four humans, influenza A(H9N2) in five humans, influenza A(H10N3) in one human, an influenza A(H1N1) variant ((H1N1)v) virus in one human, an influenza A(H1N2)v virus in one human, and influenza A(H3N2)v virus in one human were reported officially. 

Circulation of influenza viruses with zoonotic potential in animals: 

-- High pathogenicity avian influenza (HPAI) events in poultry and non-poultry animal species continue to be reported to the World Organisation for Animal Health (WOAH).{3} 

-- The Food and Agriculture Organization of the United Nations (FAO) also provides a global update on avian influenza viruses with pandemic potential.{4} 

-- Additionally, low pathogenicity avian influenza viruses as well as swine influenza viruses continue to circulate in animal populations. 

Risk assessment {5}: 

-- Sustained human to human transmission has not been reported associated with the above-mentioned human infection events. 

-- Based on information available at the time of this risk assessment update, the overall public health risk from currently known influenza A viruses detected at the human-animal interface has not changed and remains low. 

-- The occurrence of sustained human-to-human transmission of these viruses is currently considered unlikely. 

-- Although human infections with viruses of animal origin are infrequent, they are not unexpected at the human-animal interface.  

Risk management: 

-- Candidate vaccine viruses (CVVs) for zoonotic influenza viruses for pandemic preparedness purposes were reviewed and updated at the February 2026 WHO consultation on influenza vaccine composition for use in the northern hemisphere 2026-2027 influenza season. 

-- A detailed summary of zoonotic influenza viruses characterized since September 2025 is published here and updated CVVs lists are published here.  

IHR compliance {6}: 

-- This includes any influenza A virus that has demonstrated the capacity to infect a human and its haemagglutinin (HA) gene (or protein) is not a mutated form of those, i.e. A(H1) or A(H3), circulating widely in the human population. 

-- Information from these notifications is critical to inform risk assessments for influenza at the human-animal interface.  

Avian influenza viruses in humans -  Current situation:  

-- Since the last risk assessment of 22 January 2026, four laboratory-confirmed human cases of A(H5N1) infection were detected in Bangladesh (one case) and Cambodia (three cases).  

-- A(H5N1), Bangladesh  

- On 9 February 2026, the National International Health Regulations Focal Point of Bangladesh notified WHO of a laboratory-confirmed human case of avian influenza A(H5) infection in a child from Chattogram Division. 

- The patient, with no known comorbidities, developed symptoms on 21 January 2026 and was admitted to hospital on 28 January.  

- A nasopharyngeal swab was collected on 29 January as part of the Hospital-based Influenza Surveillance (HBIS) platform for influenza-like illness (ILI) and severe acute respiratory infection (SARI) sentinel surveillance in Bangladesh. 

- The patient was referred to a specialized private hospital and admitted to intensive care on 31 January. 

- The patient died on 1 February.  

- On 7 February, the Institute of Epidemiology, Disease Control and Research (IEDCR), serving as the National Influenza Centre (NIC), received and tested the sample, confirming influenza A(H5) by realtime reverse transcription polymerase chain reaction (RT-PCR) on the same day. 

- Virus characterization and whole genome sequencing was conducted at International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), which confirmed that the A(H5N1) virus belongs to clade 2.3.2.1a of highly pathogenic avian influenza A(H5N1) virus (Gs/GD lineage), similar to the clade of viruses circulating in local poultry since around 2011. 

- Genetic sequence data are available in GISAID (EPI_ISL_20367262; submission date 19 Feb 2026; Institute of Epidemiology, Disease Control & Research (IEDCR)). 

- The case had exposure to household poultry, with two ducks and one chicken reportedly dying shortly before the case’s illness onset. 

- Animal and environmental samples were collected and tested with RT-PCR and serology by the zoonotic investigation team of icddr,b. 

- Two samples from ducks in the community and two samples from chicken meat in the freezer of household tested positive for influenza A(H5). 

- Samples from symptomatic close human contacts tested negative for influenza.  

- This is the first confirmed human case of avian influenza A(H5) reported in Bangladesh in 2026. 

- In 2025, four human cases of avian influenza A(H5) were reported.  

- According to reports received by WOAH, various influenza A(H5) subtypes continue to be detected in wild and domestic birds in Africa, the Americas, Asia and Europe. 

- Infections in non-human mammals are also reported, including in marine and land mammals.{7} 

- A list of bird and mammalian species affected by HPAI A(H5) viruses is maintained by FAO.{8}   

-- A(H5N1), Cambodia 

- Between 15 February and 31 March 2026, Cambodia notified WHO of three laboratory-confirmed cases of A(H5N1) virus infection. 

(...)

- All cases above had exposure to sick or dead backyard poultry. 

- The first case was detected through SARI surveillance. 

- The other two cases were detected following the detection of A(H5N1) in sick and dead poultry which initiated deployment of rapid response teams from the public health sector and active case finding. 

- The last case was identified as having had exposure to sick and dead poultry, sampled and then developed ILI symptoms. 

- Three human infections with A(H5N1) viruses have been confirmed in Cambodia in 2026 and none have been fatal. 

- Influenza A(H5N1) viruses continue to be detected in domestic birds in Cambodia in 2026, including in areas where human cases have been detected.{9} 

- Where the information is available, the genetic sequence data from the viruses from the human cases closely matches that from recent local animal viruses and are identified as clade 2.3.2.1e viruses. 

- From the information available thus far on these recent human cases, there is no indication of human-to-human transmission of the A(H5N1) viruses.   

-- A(H9N2), China  

- Between 9 February and 20 March 2026, China notified WHO of four laboratory-confirmed cases of A(H9N2) virus infection. 

(...)

-- A(H9N2), Italy, ex-Senegal {10} 

- On 21 March 2026, Italy notified WHO of the detection of A(H9N2) virus in an adult male. 

- The case had travelled to Senegal for more than six months and returned to Italy in mid-March 2026. 

- Upon arrival in Italy, the case sought medical care, presenting with fever and persistent cough that had been present since mid-January. 

- Laboratory investigations conducted on a bronchoalveolar lavage specimen on 16 March showed a positive Mycobacterium tuberculosis result, as well as detection of an un-subtypeable influenza A virus. 

- The case was admitted to an isolation room under airborne precautions in a negative-pressure room and received antitubercular and antiviral treatment. 

- As of 24 March, the patient was clinically stable and improving.  

- On 20 March 2026, the regional reference laboratory confirmed the A(H9) subtype, and on 21 March, influenza A(H9N2) was confirmed by next-generation sequencing. 

- Initial genetic findings suggest the infection was likely acquired from an avian source linked to Senegal. 

- Additional samples have been sent to Italy’s National Influenza Center, where further characterization confirmed virus subtype Influenza A(H9N2), with close genetic similarity to strains previously identified in poultry in Senegal. 

- No direct exposure to animals, wildlife or rural environments was identified. 

- There was also no reported contact with symptomatic or confirmed human cases. 

- Further epidemiological investigations on the source of exposure are ongoing. 

- Contacts identified in Senegal were asymptomatic. 

- All identified and traced contacts in Italy have tested negative for influenza and completed the period of active monitoring for the onset of symptoms and the quarantine required by national guidelines. 

- Human infections with influenza A(H9) viruses have been reported from countries in Africa and Asia, where these viruses are also detected in poultry. 

- This is the first imported human case of avian influenza A(H9N2) reported in the European Region. 

-- Risk Assessment for avian influenza A(H9N2):  

- 1. What is the global public health risk of additional human cases of infection with avian influenza A(H9N2) viruses?  

Most human cases follow exposure to the A(H9N2) virus through contact with infected poultry or contaminated environments. 

Most human infections of A(H9N2) to date have resulted in mild clinical illness. 

Since the virus is endemic in poultry in multiple countries in Africa and Asia, additional human cases associated with exposure to infected poultry or contaminated environments are expected but remain unusual. 

The impact to public health if additional sporadic cases are detected is minimal. 

The overall global public health risk is low.  

- 2. What is the likelihood of sustained human-to-human transmission of avian influenza A(H9N2) viruses related to these events?  

At the present time, no sustained human-to-human transmission has been identified associated with the recently reported human infections with A(H9N2) viruses. 

Current evidence suggests that A(H9N2) viruses from these cases did not acquire the ability of sustained transmission among humans, therefore sustained human-to-human transmission is thus currently considered unlikely.  

- 3. What is the likelihood of international spread of avian influenza A(H9N2) virus by travellers?  

Should infected individuals from affected areas travel internationally, their infection may be detected in another country during travel or after arrival, such as in the case reported by Italy. 

If this were to occur, further community level spread is considered unlikely as current evidence suggests the A(H9N2) virus subtype has not acquired the ability to transmit easily among humans.  

-- A(H10N3), China  

- On 9 February 2026, China notified WHO of one laboratory-confirmed case of human infection with an avian influenza A(H10N3) virus in a 34-year-old man from Guangdong province who developed symptoms on 29 December 2025. 

- On 1 January 2026, he was admitted to hospital and diagnosed with severe pneumonia, severe acute respiratory distress syndrome (ARDS) and sepsis. 

- Oseltamivir treatment was initiated on 3 January. 

- The patient's condition was stable at the time of reporting. 

- On 12 January, the sample was sent to the provincial laboratory for testing. 

- The result was positive for A(H10N3). On 14 January, the National Influenza Center confirmed the positive result.    

- The patient works near two establishments that keep live poultry on the premises and chickens are present at the household. 

- Environmental samples collected from sites related to likely poultry exposure, including the patient's home, the workplace and a nearby poultry market tested negative for A(H10N3) influenza virus. 

- No further cases were detected among contacts of these cases.   

- A total of 98 close contacts of the patient were traced.  

- Since 2021, a total of seven cases of human avian influenza A(H10N3) virus infection have been reported globally and all were from China.   

-- Risk Assessment for avian influenza A(H10N3):   

- 1. What is the global public health risk of additional human cases of infection with avian influenza  A(H10N3) viruses?   

Human infections with avian influenza A(H10) viruses have been detected and reported previously.   

The circulation and epidemiology of these viruses in birds have been previously reported.{12} 

Avian influenza A(H10N3) viruses with different genetic characteristics have been detected previously in wild birds since the 1970s and more recently spilled over to poultry in some countries. 

As long as the virus continues to circulate in birds, further human cases can be expected but remain unusual. 

The impact to public health if additional sporadic cases are detected is minimal. 

The overall global public health risk of additional sporadic human cases is low.    

- 2. What is the likelihood of sustained human-to-human transmission of avian influenza A(H10N3)   viruses?   

No sustained human-to-human transmission has been identified associated with the event described above or past events with human cases of influenza A(H10N3) viruses. 

Current epidemiologic and virologic evidence suggests that contemporary influenza A(H10N3) viruses assessed by the Global Influenza Surveillance and response System (GISRS) have not acquired the ability of sustained transmission among humans, therefore sustained human-to-human transmission is thus currently considered unlikely.    

- 3. What is the likelihood of international spread of avian influenza A(H10N3) virus by travellers?   

Should infected individuals from affected areas travel internationally, their infection may be   detected in another country during travel or after arrival. 

If this were to occur, further community   level spread is considered unlikely based on current limited evidence.  

Swine influenza viruses in humans  

-- Influenza A(H1N1)v, China  

- On 20 March 2026, China notified WHO of a laboratory-confirmed case of A(H1N1)v influenza virus infection in a child from Yunnan province. 

- The patient had onset of illness on 30 January 2026, was hospitalized on 2 February with pneumonia, and recovered in a few days. 

- The patient had reported exposure to domestic pigs prior to illness onset.  

-- Influenza A(H1N2)v, China 

- On 3 February 2026, China notified WHO of a laboratory-confirmed case of A(H1N2)v influenza virus infection in a child from Yunnan province. 

- The patient had onset of mild illness on 20 January 2026, and the infection was laboratory-confirmed on 2 February 2026. 

- The patient had reported exposure to domestic pigs prior to illness onset. This case and the one above are not epidemiologically linked.  

-- Influenza A(H3N2)v, Brazil 

- On 26 January 2026, Brazil notified WHO of a laboratory-confirmed case of A(H3N2)v influenza virus infection. 

- On 1 September 2025, a male child residing in the state of Mato Grosso do Sul presented with ILI symptoms and was taken to a health unit on 2 September. 

- The patient had no reported comorbidities or recent travel history and reported being vaccinated against seasonal influenza in the last campaign. 

- On 9 September, a respiratory sample was collected at the health unit, which is a sentinel unit for ILI. 

- On 12 September, the Central Public Health Laboratory of Mato Grosso do Sul (Lacen/MS) reported that the RT-qPCR test for influenza A virus subtyping amplified the influenza A marker along with the H3 marker, indicating a swine-origin variant of the influenza H3 virus. 

- The sample was sent to the National Influenza Center (NIC) of the Adolfo Lutz Institute, where the A(H3N2)v was confirmed by molecular tests and genomic sequencing. 

- The sequences were entered into GISAID on 1 October. 

- The sample was also shared with the WHO Collaborating Centre at the US Centers for Disease Control and Prevention (CDC), where it was genomically and antigenically characterized. 

- An epidemiological investigation was conducted, which identified the case as a student at an agricultural school where pigs and laying hens are raised, although the institution's coordinators reported that the students had not had direct contact with pigs recently. 

- It was reported that the case had contact with classmates who presented ILI symptoms during this period. 

- All household contacts were vaccinated against seasonal influenza in the 2025 season, except for the patient's mother. 

- To date, no other human cases of infection with the A(H3N2)v virus have been detected in association with this case. 

-- Risk Assessment:   

- 1. What is the public health risk of additional human cases of infection with swine influenza viruses?   

Swine influenza viruses circulate in swine populations in many regions of the world. 

Depending on geographic location, the genetic characteristics of these viruses differ. 

Most human cases are exposed to swine influenza viruses through contact with infected animals or contaminated environments. 

Human infection tends to result in mild clinical illness in most cases. 

Since these viruses continue to be detected in swine populations, further human cases are expected. 

The impact to public health if additional sporadic cases are detected is minimal. 

The overall risk of additional sporadic human cases is low.   

- 2. What is the likelihood of sustained human-to-human transmission of swine influenza viruses?    

No sustained human-to-human transmission was identified associated with the events described above. 

Current evidence suggests that contemporary swine influenza viruses have not acquired the ability of sustained transmission among humans, therefore sustained human-to-human transmission is thus currently considered unlikely.  

- 3. What is the likelihood of international spread of swine influenza viruses by travelers?    

Should infected individuals from affected areas travel internationally, their infection may be detected in another country during travel or after arrival. 

If this were to occur, further community level spread is considered unlikely as current evidence suggests that these viruses have not acquired the ability to transmit easily among humans.  

For more information on zoonotic influenza viruses, see the report from the WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2026-2027 Northern Hemisphere Influenza Season that was held on 23-26 February 2026 at this link.  

Overall risk management recommendations: 

Surveillance and investigations 

• Due to the constantly evolving nature of influenza viruses, WHO continues to stress the importance of global strategic surveillance in animals and humans to detect virologic, epidemiologic and clinical changes associated with circulating influenza viruses that may affect human (or animal) health. 

- Continued vigilance is needed within affected and neighbouring areas to detect infections in animals and humans. 

- Close collaboration with the animal health and environment sectors is essential to understand the extent of the risk of human exposure and to prevent and control the spread of animal influenza. 

- WHO has published guidance on surveillance for human infections with avian influenza A(H5) viruses. 

• As the extent of influenza virus circulation in animals is not clear, epidemiologic and virologic surveillance and the follow-up of suspected human cases should continue systematically. 

- Guidance on investigation of non-seasonal influenza and other emerging acute respiratory diseases has been published on the WHO website. 

• Countries should: 

- increase avian influenza surveillance in domestic and wild birds, 

- enhance surveillance for early detection in cattle populations in countries where HPAI is known to be circulating, include HPAI as a differential diagnosis in non-avian species, including cattle and other livestock populations, with high risk of exposure to HPAI viruses; 

- monitor and investigate cases in non-avian species, including livestock, report cases of HPAI in all animal species, including unusual hosts, to WOAH and other international organizations, 

- share genetic sequences of avian influenza viruses in publicly available databases, 

- implement preventive and early response measures to break the HPAI transmission cycle among animals through movement restrictions of infected livestock holdings and strict biosecurity measures in all holdings, 

- employ good production and hygiene practices when handing animal products, and 

- protect persons in contact with suspected/infected animals.{11} 

- More guidance can be found from WOAH and FAO. 

• When there has been human exposure to a known outbreak of an influenza A virus in domestic poultry, wild birds or other animals – or when there has been an identified human case of infection with such a virus – enhanced surveillance in potentially exposed human populations becomes necessary. 

- Enhanced surveillance should consider the health care seeking behaviour of the population, and could include a range of active and passive health care and/or communitybased approaches, including: 

* enhanced surveillance in local influenza-like illness (ILI)/SARI systems, 

* active screening in hospitals and of groups that may be at higher occupational risk of exposure, and 

* inclusion of other sources such as traditional healers, private practitioners and private diagnostic laboratories. 

• Vigilance for the emergence of novel influenza viruses with pandemic potential should be maintained at all times including during a non-influenza emergency. 

- In the context of the cocirculation of SARS-CoV-2 and influenza viruses, WHO has updated and published practical guidance for integrated surveillance. 

Notifying WHO 

• All human infections caused by a new subtype of influenza virus are notifiable under the International Health Regulations (IHR, 2005).{12,13} 

- State Parties to the IHR (2005) are required to immediately notify WHO of any laboratory-confirmed{14} case of a recent human infection caused by an influenza A virus with the potential to cause a pandemic{15}. 

- Evidence of illness is not required for this report. Evidence of illness is not required for this report. 

• WHO published the case definition for human infections with avian influenza A(H5) virus requiring notification under IHR (2005): https://www.who.int/teams/global-influenzaprogramme/avian-influenza/case-definitions. 

Virus sharing and risk assessment 

• It is critical that these influenza viruses from animals or from humans are fully characterized in appropriate animal or human health influenza reference laboratories. 

- Under WHO’s Pandemic Influenza Preparedness (PIP) Framework, Member States are expected to share influenza viruses with pandemic potential on a timely basis16 with a WHO Collaborating Centre for influenza of GISRS. 

- The viruses are used by the public health laboratories to assess the risk of pandemic influenza and to develop candidate vaccine viruses.  

• The Tool for Influenza Pandemic Risk Assessment (TIPRA) provides an in-depth assessment of risk associated with some zoonotic influenza viruses – notably the likelihood of the virus gaining human-to-human transmissibility, and the impact should the virus gain such transmissibility. 

- TIPRA maps relative risk amongst viruses assessed using multiple risk elements. 

- The results of TIPRA complement those of the risk assessment provided here, and those of prior TIPRA risk assessments are published at  http://www.who.int/teams/global-influenza-programme/avianinfluenza/tool-for-influenza-pandemic-risk-assessment-(tipra).  

Risk reduction 

• Given the observed extent and frequency of avian influenza in poultry, wild birds and some wild and domestic mammals, the public should avoid contact with animals that are sick or dead from unknown causes, including wild animals, and should report dead birds and mammals or request their removal by contacting local wildlife or veterinary authorities.  

• Eggs, poultry meat and other poultry food products should be properly cooked and properly handled during food preparation. Due to the potential health risks to consumers, raw milk should be avoided. WHO advises consuming pasteurized milk. If pasteurized milk isn’t available, heating raw milk until it boils makes it safer for consumption. 

• WHO has published practical interim guidance to reduce the risk of infection in people exposed to avian influenza viruses. 

Trade and travellers 

• WHO advises that travellers to countries with known outbreaks of animal influenza should avoid farms, contact with animals in live animal markets, entering areas where animals may be slaughtered, or contact with any surfaces that appear to be contaminated with animal excreta. Travelers should also wash their hands often with soap and water. All individuals should follow good food safety and hygiene practices.  

• WHO does not advise special traveller screening at points of entry or restrictions with regards to the current situation of influenza viruses at the human-animal interface. 

- For recommendations on safe trade in animals and related products from countries affected by these influenza viruses, refer to WOAH guidance.  

Links:  

- WHO Human-Animal Interface web page https://www.who.int/teams/global-influenza-programme/avian-influenza 

- WHO Influenza (Avian and other zoonotic) fact sheet https://www.who.int/news-room/fact-sheets/detail/influenza-(avian-and-other-zoonotic) 

- WHO Protocol to investigate non-seasonal influenza and other emerging acute respiratory diseases https://www.who.int/publications/i/item/WHO-WHE-IHM-GIP-2018.2 

- WHO Public health resource pack for countries experiencing outbreaks of influenza in animals:  https://www.who.int/publications/i/item/9789240076884 

- Cumulative Number of Confirmed Human Cases of Avian Influenza A(H5N1) Reported to WHO  https://www.who.int/teams/global-influenza-programme/avian-influenza/avian-a-h5n1-virus 

- Avian Influenza A(H7N9) Information https://www.who.int/teams/global-influenza-programme/avian-influenza/avian-influenza-a-(h7n9)virus 

- World Organisation of Animal Health (WOAH) web page: Avian Influenza  https://www.woah.org/en/home/ 

- Food and Agriculture Organization of the United Nations (FAO) webpage: Avian Influenza https://www.fao.org/animal-health/avian-flu-qa/en/ 

- WOAH/FAO Network of Expertise on Animal Influenza (OFFLU) http://www.offlu.org/ 

___

{1} This summary and assessment covers information confirmed during this period and may include information received outside of this period. 

{2} For epidemiological and virological features of human infections with animal influenza viruses not reported in this assessment, see the reports on human cases of influenza at the human-animal interface published in the Weekly Epidemiological Record here.  

{3} World Organisation for Animal Health (WOAH). Avian influenza. Global situation. Available at: https://www.woah.org/en/disease/avian-influenza/#ui-id-2. 

{4} Food and Agriculture Organization of the United Nations (FAO). Global Avian Influenza Viruses with Zoonotic Potential situation update. Available at: https://www.fao.org/animal-health/situation-updates/global-aiv-withzoonotic-potential. 

{5} World Health Organization (2012). Rapid risk assessment of acute public health events. World Health Organization. Available at: https://iris.who.int/handle/10665/70810. 

{6} World Health Organization. Case definitions for the four diseases requiring notification in all circumstances under the International Health Regulations (2005). Available at: https://www.who.int/publications/m/item/case-definitions-for-the-four-diseases-requiring-notification-towho-in-all-circumstances-under-the-ihr-(2005).  

{7} World Organisation for Animal Health (WOAH). Avian influenza. Global situation. Available at: https://www.woah.org/en/disease/avian-influenza/#ui-id-2. 

{8} Food and Agriculture Organization of the United Nations. Global Avian Influenza Viruses with Zoonotic Potential situation update. Available at: https://www.fao.org/animal-health/situation-updates/global-aiv-withzoonotic-potential/bird-species-affected-by-h5nx-hpai/en. 

{9} World Organisation for Animal Health. WAHIS. https://wahis.woah.org/#/in-review/7409. 

{10} World Health Organization. World Health Organization (10 April 2026). Disease Outbreak News: Avian Influenza A(H9N2) in Italy (https://www/who.int/emergencies/disease-outbreak-news/item/2026-DON597). 

{11} World Organisation for Animal Health. Statement on High Pathogenicity Avian Influenza in Cattle, 6 December 2024 (https://www.woah.org/en/high-pathogenicity-avian-influenza-hpai-in-cattle/). 

{12} World Health Organization. International Health Regulations (2005), as amended through resolutions WHA67.13 (2014), WHA75.12 (2022), and WHA77.17 (2024) (https://apps.who.int/gb/bd/pdf_files/IHR_20142022-2024-en.pdf). 

{13} World Health Organization. Case definitions for the four diseases requiring notification in all circumstances under the International Health Regulations (2005) (https://www.who.int/publications/m/item/casedefinitions-for-the-four-diseases-requiring-notification-to-who-in-all-circumstances-under-the-ihr-(2005)). 

{14} World Health Organization. Manual for the laboratory diagnosis and virological surveillance of influenza (2011) (https://apps.who.int/iris/handle/10665/44518). 

{15} World Health Organization. Pandemic influenza preparedness framework for the sharing of influenza viruses and access to vaccines and other benefits, 2nd edition (https://iris.who.int/handle/10665/341850). 

{16} World Health Organization. Operational guidance on sharing influenza viruses with human pandemic potential (IVPP) under the Pandemic Influenza Preparedness (PIP) Framework (2017) (https://apps.who.int/iris/handle/10665/259402). 

Source: 

Link: https://www.who.int/publications/m/item/influenza-at-the-human-animal-interface-summary-and-assessment--31-march-2026

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