Seasonal #surveillance in #humans in 2026 for West Nile virus (#WNV) (ECDC, July 31 '26): 158 cases so far of which 94 from #Italy

 

{Summary}

Week 31, 2026 | Produced on 30 July 2026 at 12:00, based on data submitted up until and including 29 July 2026.

Current situation

    ° Since the beginning of the 2026 transmission season, and as at 29 July, 49 areas affected by West Nile virus (WNV) have been identified in seven countries across Europe.

    ° These areas are located in: 

        § Italy (30), 

        § Greece (eight), 

        § Romania (four), 

        § France (two), 

        § North Macedonia (two), 

        § Spain (two) and 

        § Germany (one).

    ° The seven countries have reported 158 locally acquired human cases of WNV infection: 

        § Italy has reported 94, 

        § Greece 42, 

        § North Macedonia seven, 

        § Spain seven, 

        § Romania five, 

        § France two and 

        § Germany one case.

    ° This week, 14 areas are reported as affected for the first time this season. The affected areas identified as at 29 July 2026 are listed in Table 1 and shown in Map 1 below.

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{In Yellow, areas already affected since the beginning of the season.}

{In Red, areas newly affected this week.}

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Source: 

Link: https://www.ecdc.europa.eu/en/west-nile-fever/surveillance-and-disease-data/disease-data-ecdc

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#Zoonotic neglected tropical #diseases at the animal-human interface in the Greater #Mekong Subregion: Two decades of surveillance in #Laos and #Cambodia

 

Abstract

Zoonotic neglected tropical diseases (NTDs) remain a substantial but under-recognised source of human morbidity and economic concern in the Greater Mekong Subregion, particularly in settings characterised by close human–animal interaction. This article represents a narrative synthesis of zoonotic disease research conducted in Laos and Cambodia between 2000 and 2025. The review integrates published literature with findings from long-term surveillance programmes conducted by the authors and collaborating institutions in Laos, with comparative insights from Cambodia, to examine the presence, distribution, diversity, and drivers of zoonotic pathogens at the human–animal interface. Evidence demonstrates the endemic presence of a wide range of parasitic, bacterial, and viral zoonoses, including Taenia solium, Trichinella spp., Streptococcus suis, rickettsial infections, melioidosis, hepatitis E virus, and Japanese encephalitis virus. Some of these pathogens are sustained within smallholder livestock systems, informal slaughter, farming practises, food networks, and wet market environments, where limited diagnostic capacity and fragmented surveillance obscure true disease presence. Surveillance innovations, including abattoir-based sampling, cross-sectoral serological studies, environmental surveillance approaches, and molecular diagnostic tools, have improved pathogen detection but have also highlighted persistent structural and behavioural barriers to control. Socio-cultural practices, occupational exposure, wildlife trade, and economic dependencies reinforce transmission dynamics, indicating that biomedical interventions alone are insufficient. Instead, zoonotic disease persistence reflects the interaction of livestock production systems, environmental conditions, diagnostic limitations, and entrenched human behaviours. This review emphasises the need for integrated One Health approaches that combine strengthened surveillance, improved diagnostics, behavioural interventions, and regional collaboration. Addressing zoonotic NTDs in Laos and Cambodia requires coordinated strategies that account for both biological complexity and socio-economic context to achieve sustainable disease control and improved public health outcomes.

Source: 

Link: https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014584

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#Mutations in severe #human #H5N1 cases facilitate #evasion from human mucus and #antivirals

 

Abstract

In late 2024, two individuals in Canada and the United States were treated in intensive care for acute respiratory distress caused by infection with the avian Influenza A Virus H5N1 2.3.4.4b genotype D1.1. Viral sequence data obtained from sampling these patients indicated mixed alleles at haemagglutinin (HA) positions 190 and 226. Mutations at these positions are key determinants of HA usage of α2,6-linked sialic acids (SA), the most abundant influenza receptors in human upper respiratory tracts. Thus, these mutations raised concerns about human adaptation and pandemic potential of the H5N1 virus. In this study, we investigated the impact of the mutations at residues 190 and 226 in H5 HA. We studied the receptor binding properties, cell entry phenotypes and fitness impacts of the mutations using recombinant proteins, pseudotyped lentiviruses, and in the context of influenza viruses using reverse genetics. The mutations did not confer any detectable α2,6-linked sialic acid receptor usage either alone or in combination. Rather, viruses carrying these mutations exhibit weakened binding towards α2,3-linked sialic acid receptors. This correlated with an enhanced capacity to evade human airway mucus, and a reduced susceptibility to oseltamivir and zanamivir. This research underscores that in addition to the way HA interacts with SA as entry receptors, other factors that impact the HA/NA balance might influence the evolutionary trajectory of a zoonotic virus in the human respiratory tract. This study presents a new paradigm for the evolutionary drivers of HA, where reduced sialic acid binding can serve as an advantage for escape from host barriers and antivirals.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Medical Research Council, https://ror.org/03x94j517, MR/Y03368X/1, MR/Y015061/1, CC2127

Biotechnology and Biological Sciences Research Council, BB/Y007298/1, APP104179, BBS/E/PI/23NB000, BBS/E/PI/23NB0003

Wellcome Trust, https://ror.org/029chgv08, CC2127, 218304/Z/19/Z

Department for Environment Food and Rural Affairs, BB/Y007298/1

The Pirbright Institute, BBS/E/PI/230002A, BBS/E/PI/230001C, BBS/E/PI/230002B

Cancer Research UK, CC2127

UK Research and Innovation, https://ror.org/001aqnf71, UKRI3602

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.07.28.740943v1

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Avian #Influenza #Report: July 19 25, '26 (Wk 30) (HK CHP, July 28 '26): Three new #human #infection with #H9N2 virus in #China

 

{Excerpt}

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Avian influenza A(H9N2): 

{China}

    ° Guangdong Province: 

        § A 44-year-old man with onset on June 26, 2026. 

    ° Guangxi Zhuang Autonomous Region: 

        § A four-year-old boy with onset on June 26, 2026.  

    ° Jiangsu Province: 

        § A four-year-old boy with onset on June 22, 2026. 

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Source: 

Link: https://www.chp.gov.hk/files/pdf/2026_avian_influenza_report_vol22_wk30.pdf

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Mapping Reported Modes of #Transmission of Highly Pathogenic Avian #Influenza #H5N1 to #Humans: A Scoping Review

 

Abstract

Background

Highly Pathogenic Avian Influenza A (subtype H5N1) poses a threat to human health, and its pandemic potential emphasizes the need to better understand detailed reported transmission pathways to humans. Existing literature is outdated or lacks detailed, comprehensive analysis of the range of transmission routes and how the virus may enter the human body.

Objective

To comprehensively map all reported H5N1 transmission pathways to humans, as well as viral entry routes.

Methods

CINAHL, Embase, MEDLINE, Scopus, PubMed, grey literature, and reference lists (of included studies) were searched up to October 29th, 2025, with no language restrictions. Observational studies and grey literature reporting H5N1 transmission evidence to humans were included. Two reviewers conducted duplicate screening independently (two of three reviewers per record). One reviewer completed data extraction, which was cross-verified for accuracy by a second. Findings were summarized narratively.

Results

120 sources met inclusion criteria (70 studies, 50 grey literature). Reported H5N1 transmission pathways were classified into animal-to-human (109 of 120 sources, 90.8%; including poultry-to-human in 100 sources [83.3%] and cattle-to-human in nine sources [7.5%]), environment-to-human (32 of 120 sources, 26.7%), and human-to-human (14 of 120 sources, 11.7%). Reported transmission pathways were further classified as direct or indirect contact, synthesized, and linked to suspected routes of human entry, including mucosal entry (eyes, nose, mouth), inhalation of aerosols or droplets, ingestion, and percutaneous exposure. Entry routes are biologically plausible and do not imply relative likelihood or causal attribution.

Conclusions

There are multiple reported pathways of H5N1 exposure, and a single pathway may involve multiple ways to infect humans. Further research is needed to determine causal mechanisms, identify specific risk factors and measures of association, and strengthen evidence-based prevention strategies.

Source: 

Link: https://www.sciencedirect.com/science/article/pii/S235277142600176X?via%3Dihub

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Seasonal #surveillance in #humans in 2026 for #WNV (West Nile Virus) (ECDC, July 24 '26): 81 confirmed cases so far of which 46 in #Italy

 

{Excerpt}

Week 30, 2026 | Produced on 23 July 2026 at 09:45, based on data submitted up until and including 22 July 2026.

Current situation

    ° Since the beginning of the 2026 transmission season, and as at 22 July, 35 areas affected by West Nile virus (WNV) have been identified in six countries across Europe.

    ° These areas are located in: 

        § Italy (20), 

        § Greece (six), 

        § Romania (four), 

        § North Macedonia (two), 

        § Spain (two) and 

        § France (one).

    ° The six countries have reported 81 locally acquired human cases of WNV infection: 

        § Italy has reported 46, 

        § Greece 21, 

        § North Macedonia five, 

        § Romania five, 

        § Spain three and 

        § France one case.

    ° This week, nine areas are reported as affected for the first time this season. The affected areas identified as at 22 July 2026 are listed in Table 1 and shown in Map 1 below.

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Table 1. Areas affected by West Nile virus during the 2026 transmission season at 22 July, by country and NUTS3 or GAUL1 area

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Source: 

Link: https://www.ecdc.europa.eu/en/west-nile-fever/surveillance-and-disease-data/disease-data-ecdc

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#Oseltamivir #Resistance in #Human #Influenza #H5N1 and #H7N9 Infections: A Mini Review

 

Abstract

Avian influenza viruses (AIVs) have been reported to cause infections in humans following avian-to-human transmission, resulting in a range of clinical outcomes. A(H5N1) and A(H7N9) infections, which constitute the majority of human AIV cases, are responsible for severe infections leading to high mortality. The neuraminidase inhibitor oseltamivir is expected to play a major role for the control of AIV infections in humans. However, the emergence of resistance may compromise the impact of antiviral therapy. The objective of this article is to review human cases of A(H5N1) and A(H7N9) infections for which mutations of oseltamivir resistance were detected. Neuraminidase mutations rapidly occurred in a subtype-specific manner, with H274Y and N294S substitutions predominating in A(H5N1) cases and the R292K substitution in A(H7N9) cases. Serious clinical outcomes and mortality were seen in most A(H5N1) and A(H7N9) cases despite oseltamivir therapy, thus highlighting the need for improving antiviral strategies against these AIVs.

Source: 

Link: https://academic.oup.com/ofid/article/13/7/ofag393/8722865

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A lethal #human #H5N5 #influenza virus isolate exhibits low #pandemic #risk traits

 

Abstract

In fall of 2025, a fatal infection of highly pathogenic avian influenza (HPAI) virus H5N5 occurred. To define the risk of this emerging virus to humans, we performed a comprehensive analysis based on our established triage. Serological analysis revealed that humans across all birth years had no detectable neutralizing antibodies to this H5N5 isolate. Further characterization revealed a lack of phenotypic signatures associated with epidemiologically successful influenza viruses in humans, including reduced replication in human airway cells and an avian-like pH of inactivation. Additionally, assessment of H5N5 in ferrets revealed a lack of direct contact transmission and moderate disease severity. H5N5 infection in ferrets with prior immunity against the 2009 H1N1 pandemic strain resulted in fewer clinical signs and reduced viral shedding. Together our data suggest that the current H5N5 HPAI lineage poses a low pandemic risk.

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.07.20.739507v1

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Avian #Influenza #Report: July 12 - 18 '26 (Wk 29) (HK CHP, July 21 '26): 1 New #Human Case of Infection with #H5 virus in #Bangladesh

 

{Excerpt}

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    ° Avian influenza A(H5): 

        § Bangladesh: 

            - Sylhet Division: A child with onset on May 17, 2026. 

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Source: 

Link: https://www.chp.gov.hk/files/pdf/2026_avian_influenza_report_vol22_wk29.pdf

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#WNV in #humans, the European Region, Weekly #Report (ECDC, July 17 '26): #Italy (21), #Greece (7), North #Macedonia (2), #Romania (2) & #Spain (2) cases so far

 

{Excerpt}

Week 29, 2026 | Produced on 17 July 2026 at 08:30, based on data submitted up until and including 15 July 2026.

Current situation

    ° Since the beginning of the 2026 transmission season, and as at 15 July, 28 areas affected by West Nile virus (WNV) have been identified in five countries across Europe {1}.

    ° These areas are located in: 

        § Italy (17), 

        § Greece (five), 

        § North Macedonia (two), 

       § Romania (two) and 

        § Spain (two).

    ° The five countries have reported 34 locally acquired {2} human cases of WNV infection: 

        § Italy has reported 21, 

        § Greece seven,     

        § North Macedonia two, 

        § Romania two and 

        § Spain two cases.

    ° This week, 17 areas are reported as affected for the first time this season. The affected areas identified as at 15 July 2026 are listed in Table 1 and shown in Map 1 below.

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Table 1. Areas affected by West Nile virus during the 2026 transmission season at 15 July, by country and NUTS3 or GAUL1 area

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* ‘First reported this week’ indicates that the affected area was not included in the previous weekly overview.

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Source: 

Link: https://wnv-weekly.ecdc.europa.eu/

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#Autoantibodies against type I #interferons in patients with #zoonotic #H7N9 #influenza: an observational case–control study

 

Summary

Background

The determinants of the species barrier preventing human infections with avian influenza A viruses (IAV) are incompletely understood. We previously identified loss-of-function variants of the interferon-regulated antiviral factor MxA as a genetic factor for increased susceptibility to infections with the H7N9 subtype. Given the central role of type I IFNs (IFN-I) in antiviral defence, we hypothesised that IFN-I-neutralising autoantibodies may similarly predispose to zoonotic H7N9 infection.

Methods

In this observational case–control study, serum samples collected between 2013 and 2017 from 199 Chinese patients with laboratory-confirmed H7N9 infection and 531 healthy, uninfected controls (269 poultry workers, 262 close contacts) were screened for IgG autoantibodies binding IFNα2, IFNβ1b, or IFNω using a multiplex bead-based assay. Positive samples were tested for IFN-neutralising activity in a luciferase-based reporter assay. To confirm their ability to block IFNα2-mediated antiviral activity, selected samples (n = 19) were analysed in IAV infection experiments. Associations between age, sex, H7N9 case status, case fatality, and the presence of neutralising autoantibodies were evaluated by logistic regression. Available whole-genome sequencing data from 26 individuals with neutralising autoantibodies were screened for variants in genes linked to IFN-I autoimmunity.

Findings

Neutralising autoantibodies against at least one IFN-I were detected in 19.1% (38/199) of patients but in only 1.1% (6/531) of controls, consistent with published general population data. Most patient sera targeted IFNα2 and/or IFNω (35/199), and 18.1% (36/199) neutralised even high IFN-I concentrations of 1–10 ng/ml. The presence of neutralising autoantibodies was associated with 8.2- to 25.3-fold higher odds of H7N9 infection (p < 0.0001), depending on antibody specificity and reference group. Autoantibody prevalence increased significantly with age in patients (44.8% ≥70 years; OR = 1.05; 95% CI 1.02–1.07; p = 0.0001), but was not associated with sex (OR for males vs. females = 0.52; 95% CI 0.23–1.14; p = 0.106). All selected sera containing neutralising autoantibodies blocked IFNα2-induced antiviral activity in cell culture. No known genetic predisposition for IFN-I autoimmunity was identified.

Interpretation

Our findings suggest that IFN-I-targeting autoimmunity is associated with susceptibility to zoonotic IAV infection with the H7N9 subtype, and possibly also other subtypes, including panzootic H5N1. Given the ease of implementation, screening for anti-IFN-I autoantibodies could be readily integrated into surveillance or targeted testing. This could be relevant in environments with increased exposure to zoonotic IAVs.

Funding

Shenzhen Medical Research Fund, National Natural Science Foundation of China, Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences, Guangdong Provincial Science and Technology Program, Program for Youzuzhikeyan of Shenzhen University, German Research Foundation, Swiss National Science Foundation.

Source: 

Link: https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(26)00271-9/fulltext

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Pan-continental #spillover #risk: integrated spatiotemporal, transmissibility and #surveillance analysis of avian #influenza #H5N1 in #Africa

 

Abstract

Background: 

The HPAI H5N1 panzootic represents a critical threat to human health in Africa, where traditional poultry systems and dense human-animal interfaces facilitate frequent zoonotic spillover. While sporadic human cases raise pandemic concerns, continent-wide integration of spatial dynamics, transmissibility indicators, and surveillance performance has been lacking. This study quantifies avian influenza transmission over two decades across Africa, identifies geographical hotspots, and evaluates the responsiveness of current surveillance systems.

Methods: 

We analysed 8,037 avian influenza outbreak events and 369 laboratory-confirmed human cases, predominantly caused by HPAI H5N1 (2004–2025), using harmonised data from FAO (EMPRES-i+), WHO, and WOAH. A Bayesian Besag-York-Mollié (BYM) spatiotemporal model estimated residual transmission risks and Incidence Rate Ratios (IRR) by subtype. The basic reproduction number (R₀) was derived via an exponential growth model applied to human outbreak phases across infectious durations of 7–30 days. Surveillance responsiveness was assessed by quantifying notification delays between clinical observation and official reporting.

Results: 

Risk of infection in animals: HPAI H5N1 was the dominant strain, representing 87.8% of animal cases, with Egypt acting as the primary epidemiological epicentre (66% of total records). The spatiotemporal model revealed that H5N1 is associated with a significantly higher risk of animal infection (IRR = 8.37; 95% CI: 6.65–10.53). Although 71% of outbreaks were reported within 5 days of detection, significant delays (≥15 days) occurred in 12% of cases, with notable regional disparities. Risk of infection in human: H5N1 was associated with a 67-fold increase in the incidence of human cases compared to other subtypes (IRR = 66.78; 95% CI: 25.29–176.37). Sensitivity analyses yielded R0 estimates ranging from 1.05 (95% CI: 0.91–1.31) to 1.23 (95% CI: 0.60–2.33), indicating localised epidemic potential.

Conclusion: 

Our findings highlight a persistent and geographically heterogeneous H5N1 reservoir in Africa with high zoonotic affinity. Although sustained human-to-human transmission remains limited, the identification of dual poultry-human hotspots and localised R0 peaks underscores the urgent need for geographically targeted One Health interventions. Strengthening real-time reporting systems and improving biosecurity in high-risk poultry value chains are critical to mitigating future pandemic threats on the continent.

Source: 

Link: https://www.frontiersin.org/journals/epidemiology/articles/10.3389/fepid.2026.1813211/full

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Occupationally Exposed and General #Population #Antibody #Profiles to #Influenza A Viruses Circulating in #Swine as Indication of Zoonotic #Risk

 

Abstract

Persons with occupational exposure to swine might be at disproportionate risk for zoonotic swine influenza A virus. To evaluate human antibody responses, we tested serum or plasma from swine veterinarian, farm employee, and general population cohorts by hemagglutination inhibition assays against representative swine and human seasonal influenza vaccine strains. We analyzed hemagglutination inhibition data by antigenic cartography to assess strain relationships and reproduction number modeling to evaluate pandemic potential using age-stratified immunity profiles. Occupationally exposed groups had lower human seasonal vaccine uptake (45.5% vs. 70%) and lower odds of seropositivity to several H1 and H3 strains from swine than did general population cohorts. One swine strain exhibited significant antigenic drift (3.62 antigenic units) from its nearest vaccine strain. Multiple strains required lower reproduction number thresholds for pandemic spread (1.09–1.35) than recorded pandemic strains (1.46–1.80), demonstrating that population immunity gaps heighten zoonotic risk to circulating swine H1 and H3 strains.

Source: 

Link: https://wwwnc.cdc.gov/eid/article/32/8/25-1995_article

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Avian #Influenza #Report: July 5 – 11 '26 (Wk 28) (HK CHP, July 14, 2026)

{Excerpt}

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Avian influenza A(H5N1) 

    

    ° Phnom Penh {Cambodia}: 

        

        - The case involved a 9-month-old girl.

        - She has been isolated in the hospital and is receiving intensive medical care. 

        - The source of infection has not yet confirmed and the investigation is ongoing. 

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Source: 

Link: https://www.chp.gov.hk/files/pdf/2026_avian_influenza_report_vol22_wk28.pdf

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Seasonal #surveillance in #humans in 2026 for #WNV - Update (ECDC, July 10 '26): #Italy reported 6 cases, #Macedonia 2, #Romania 2, #Greece 1, #Spain 1

 

Week 28, 2026 | Produced on 9 July 2026 at 08:45, based on data submitted up to 8 July 2026.

Current situation

    ° Since the beginning of the 2026 transmission season, and as of 8 July, 11 areas affected by West Nile virus (WNV) have been identified in five countries across Europe {1}.

    ° These areas are located in: 

        - Italy (five), 

        - North Macedonia (two), 

        - Romania (two), 

        - Greece (one) and 

        - Spain (one).

    ° The five countries have reported 12 locally acquired {2} human cases of WNV infection: 

        - Italy has reported six, 

        - North Macedonia two, 

        - Romania two, 

        - Greece one and 

        - Spain one case.

    ° This week, five areas are reported as affected for the first time this season. 

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Table 1. Areas affected by West Nile virus during the 2026 transmission season as of 8 July, by country and NUTS3 or GAUL1 area

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{*} ‘First reported this week’ indicates that the affected area was not included in the previous weekly overview.

{1} European Union/European Economic Area countries and selected EU-neighbouring countries (Albania, Bosnia and Herzegovina, Kosovo**, Montenegro, North Macedonia, Serbia and Türkiye).

{**} This designation is without prejudice to positions on status and is in line with UNSCR 1244/1999 and the ICJ Opinion on the Kosovo declaration of independence.↩︎

{2} Cases acquired within the reporting country.↩︎

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Source: 

Link: https://www.ecdc.europa.eu/en/west-nile-fever/surveillance-and-disease-data/disease-data-ecdc

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# Influenza at #human - #animal #interface - Summary and #risk #assessment, from 13 June to 7 July 2026 (WHO): 1 new case of #H5 virus, 2 of #H9N2 and one of #H3N2v

 

Influenza at the human-animal interface - Summary and risk assessment, from 13 June to 7 July 2026 {1} 

    • New human cases {2}: 

        ° From 13 June to 7 July 2026, based on reporting date, detections of influenza A(H5) in one human, influenza A(H9N2) in two humans, and an influenza A(H3N2) variant ((H3N2)v) virus in one human were officially reported. 

    • 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}: 

        ° There have been no reports of sustained human-to-human transmission 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 - At present, these viruses are not thought to be capable of sustained human-to-human transmission, although this could change as they evolve. 

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

    • 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 

A(H5), Bangladesh   

    ° On 15 June 2026, Bangladesh notified WHO of one laboratory-confirmed human case of avian influenza A(H5) infection in Bangladesh in a child from Sylhet Division. 

    ° The case was detected notified through the National Influenza Surveillance, Bangladesh (NISB) platform as an influenza likeillness (ILI) case.    

    ° The patient developed respiratory symptoms on 17 May 2026, received outpatient healthcare on 20 May. 

    ° A clinical sample was collected that day and was received by the Institute of Epidemiology, Disease Control and Research (IEDCR) on 4 June as part of routine surveillance. 

    ° The sample tested positive for influenza A(H5) virus by real-time reverse transcription polymerase chain reaction (RTPCR) on 11 June.    

    ° The patient is now in good health and reported no travel history and no history of exposure to poultry. 

    ° However, poultry deaths were reported in the area surrounding the patient’s residence. 

    ° The outbreak investigation team identified and followed close and possible contacts. 

    ° Samples from some of the close contacts as well as animal and environmental samples were collected for testing for influenza. 

    ° All contacts remained asymptomatic and all samples tested negative for influenza.    

    ° This is the third laboratory-confirmed human case of avian influenza A(H5) reported in Bangladesh in 2026, and the 15th human case of avian influenza A(H5) reported to WHO from Bangladesh since 2008, including two fatal cases, one reported in 2013 and one in 2026.  

Risk assessment for avian influenza A(H5) viruses:

1. What is the current global public health risk of additional human cases of infection with avian influenza A(H5) viruses?    
• Most human infections so far have been reported in people exposed to A(H5) viruses, for example, through contact with infected poultry or contaminated environments, including live poultry markets, and occasionally infected mammals and contaminated environments. 
• As long as the viruses continue to be detected in animals and related environments humans are exposed to, further human cases associated with such exposures are expected but remain unusual. 
• The impact for public health if additional sporadic cases are detected is minimal. 
• The current overall global public health risk is low.  
2. What is the likelihood of sustained human-to-human transmission of avian influenza A(H5) viruses related to the events above?    
• No sustained human-to-human transmission  has  been identified associated with the recent reported human infections with avian influenza A(H5) viruses.
•  There has been no reported human-to-human transmission of A(H5N1) viruses since 2007, although there may be gaps in investigations.
•  In 2007 and the years prior, small clusters of A(H5) virus infections in humans were reported, including some involving health care workers, where limited human-to-human transmission could not be excluded; however, sustained human-to-human transmission was not reported.
•  Current evidence suggests that influenza A(H5) viruses related to these events did not acquire the ability to efficiently transmit between people.    
3. What is the likelihood of international spread of avian influenza A(H5) viruses 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 communitylevel spread is considered unlikely as current evidence suggests these viruses have not acquired the ability to transmit easily among humans.    

A(H9N2), China  

    ° Between 12 and 23 June 2026, two laboratory-confirmed cases of A(H9N2) virus infection were detected in China. 

    ° Both cases had mild illness and were hospitalized in isolation wards at the time of reporting. 

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    ° Both cases had exposure to local live bird markets. 

    ° Samples from environments associated with the likely area of exposure of the cases tested positive for A(H9) viruses. 

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

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.  
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. 
• 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.  

Swine influenza viruses in humans 

Influenza A(H3N2)v, Brazil  

    ° On 25 June 2026, Brazil notified PAHO/WHO of a laboratory-confirmed human infection with an influenza A(H3N2)v virus detected in a child in Santa Catarina state. 

    ° The patient had symptom onset on 12 June 2026 and due to worsening respiratory symptoms, healthcare was sought on 16 June. 

    ° The patient was referred for hospital admission with a diagnosis of Severe Acute Respiratory Infection (SARI). 

    ° Upon admission, an antigen test confirmed influenza A and the patient was placed in a private respiratory isolation room and antiviral treatment was initiated. 

    ° The patient was discharged on 19 June.  

    ° A nasopharyngeal swab sample was collected on 16 June and sent to the State public health laboratory for real-time RT-PCR. 

    ° On 18 June, a swine-origin influenza H3 variant was suspected, and the sample was sent to the Laboratory of Respiratory Viruses, Exanthems, Enteroviruses, and Viral Emergencies (LVRE) at the Oswaldo Cruz Institute (Fiocruz/Rio de Janeiro) on 19 June. 

    ° Analyses confirmed the presence of an influenza A(H3N2)v virus via molecular testing and genomic sequencing. 

    ° An investigation by the state and municipality epidemiological surveillance team found that all contacts were asymptomatic before, during and after the child’s illness. 

    ° The child's grandfather worked at a swine nursery housing approximately 5,000 animals, though he noted that sanitary barriers were in place. 

    ° The child frequently visited the grandfather's home and had contact with him several days a week.  

    ° This is the first human A(H3N2)v infection detected in the Brazil in 2026 and the first case reported in the state of Santa Catarina. 

Risk assessment for swine influenza viruses:    

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 event described above. 
• Current evidence suggests that contemporary swine influenza viruses have not acquired the ability of sustained transmission among humans.   
3. What is the likelihood of international spread of swine influenza viruses 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 as current evidence suggests that these viruses have not acquired the ability to transmit easily among humans.   

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.{7} 

            - 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).{8,9} State Parties to the IHR (2005) are required to immediately notify WHO of any laboratory-confirmed {10} case of a recent human infection caused by an influenza A virus with the potential to cause a pandemic {11}. 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 basis {12} 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/ 

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

{8} 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). 

{9} 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)). 

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

{11} 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). 

{12} 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--7-july-2026

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