ETIDIOH - NEW

{Automatic translation} The Ministry of Health of Cambodia notified a case of avian influenza A(H5N1) : the patient is a 65-years-old woman from Kraing Ampil, Takeo Province . The patient is now hospitalized in Intensive Care Unit . She developed fever, cough, shortness of breath, did not report contact with diseased birds. A Response Team is investigating actively, adopting prevention and control measures. The case has been confirmed by Pasteur Institute of Cambodia . (...) Despite investigations so far excluded direct contact with diseases or dead poultry, the patient's relatives own birds and more analysis are being conducted. The Rapid Response Team continues to investigate the outbreak with the cooperation of local health authorities to find possible source of infection among poultry and humans. Close contacts of the patient are being searched and will be offered the antiviral oseltamivir for post-exposure prophylaxis. (...) Source: Cambodia Ministry of Health,  https://moh.go...

Abstract Recently, cats have emerged as potential incidental hosts for avian and human influenza A viruses (IAVs), including the highly pathogenic avian influenza (HPAI) H5N1 virus. Following an unprecedented outbreak of H5N1 HPAI in cats in Poland in June 2023, we conducted a cross-sectional epidemiological study to assess the seroprevalence of IAV, especially H5Nx , infections in domestic cats. Eight hundred thirty-five serum samples collected in June 2023 were tested using a competitive ELISA for antibodies to IAV nucleoprotein. Positive or doubtful samples were further screened for H5-specific antibodies. The overall seropositivity for IAV was 8.5% (CI 95%: 6.8%, 10.6%; 71/835 cats), and 23/68 IAV-seropositive cats (33.8%) were also seropositive for H5 antigen . Multivariable analysis identified young age (≤8 years) and male sex as significant risk factors for H5 seropositivity, while non-H5-IAV seropositivity was more common in cats aged ≥12 years. These findings suggest different...

  Antiviral Res MARTINEZ-GZEGOZEWSKA Y, Rasmussen L, Nebane NM, McKellip S, et al High-throughput screening for identification of Influenza A inhibitors using a cell-based immunofluorescence assay. Antiviral Res. 2025 Jun 6:106209. doi: 10.1016/j.antiviral.2025.106209. PubMed           Abstract available Arch Virol LU Y, Ni J, Huang S, Guo Y, et al Epidemiological characteristics of human parainfluenza virus infections and phylogenetic analysis of human parainfluenza virus type 3 isolated from children with respiratory tract infections from 2020 to 2022 in Zhejiang, China. Arch Virol. 2025;170:157. PubMed           Abstract available JIN H, Cho YR, Jung YT Single-particle quantification of SARS-CoV-2 virus-like particles using flow virometry. Arch Virol. 2025;170:149. PubMed           Abstract available Cell STEVENS J, Culberson E, Kinder J, Ramiriqui A, et al Mic...

Abstract Highly pathogenic avian influenza (HPAI) viruses with H5 hemagglutinin (HA) genes (clade 2.3.4.4b) are causing an ongoing panzootic in wild birds . Circulation of these viruses is associated with spillover infections in multiple species of mammals , including a large, unprecedented outbreak in American dairy cattle . Before widespread on-farm testing, there was an unmet need for genomic surveillance. Infected cattle can shed high amounts of HPAI H5N1 viruses in milk , allowing detection in pasteurized retail dairy samples. Over a 2-month sampling period in one Midwestern city , we obtained dairy products processed in 20 different states. Here we demonstrate that a tiled-amplicon sequencing approach produced over 90% genome coverage at greater than 20x depth from 5 of 13 viral RNA positive samples, with higher viral copies corresponding to better sequencing success. The sequences clustered phylogenetically within the rest of the cattle outbreak sequences reported. A combination...

  {Excerpt} Time Period: June 01, 2025 - June 07, 2025 - H5 Detection :  4 sites ( 1.1% ) - No Detection :  370 sites ( 98.9% ) - No samples in last week :  73 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/bird-flu/h5-monitoring/index.html ____

 Sea Otters in Hokkaido Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6551 ____

A small commercial flock of 69 chickens, 23 ducks and 5 geese. Increased mortality reported in chickens as well as a drop in egg production in the ducks. Samples were taken and tested positive for HPAI H5N1. Location:  Kirklees, West Yorkshire, England. Source: WOAH,  https://wahis.woah.org/#/in-review/6552 ____

Abstract Highly pathogenic avian influenza causes substantial poultry losses and zoonotic concerns globally . Duck vaccination against highly pathogenic avian influenza began in France in October 2023. Our assessment predicted that 314–756 outbreaks were averted in 2023–2024, representing a 96%–99% reduction in epizootic size, likely attributable to vaccination. Source: US Centers for Disease Control and Prevention,  https://wwwnc.cdc.gov/eid/article/31/7/24-1445_article ____

  {Excerpt} Time Period: May 25, 2025 - May 31, 2025 - H5 Detection :  10 sites ( 2.5% ) - No Detection :  389 sites ( 97.5% ) - No samples in last week :  52 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

Abstract The highly pathogenic avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b has rapidly disseminated globally , with mammalian infections reported in multiple species. Recent evidence of mammal-to-mammal transmission has heightened concerns about the virus’s potential adaptation to mammals . The polymerase basic 2 (PB2) protein E627K mutation appears to be of key importance for mammalian adaptation. We isolated an HPAI H5N1 clade 2.3.4.4b virus from wild birds in Korea with 96% E and 4% K at amino acid position 627 of PB2 . To investigate the genomic characteristics of this clade regarding mammalian adaptation, we studied the replication and transmission of the H5N1 virus in mice. Two experiments with different challenge-to-contact ratios were conducted to assess transmission dynamics and mutation development . In experiment 1, a 4:1 challenge-to-contact ratio resulted in 100% transmission among direct-contact mice , with all mice succumbing to the infection. In experiment 2, a 1:...

Abstract Highly pathogenic avian influenza virus (HPAIV) of H5 and H7 subtypes has emerged as one of the most important zoonotic pathogens in the 21st century with significant economic consequences. The recent outbreak of H5N1 avian influenza (AI) in dairy cattle highlighted the importance of early detection in managing and mitigating HPAIV outbreaks. A successful high-speed diagnostic response requires rapid site and specimen access, minimal time for test protocols, and prompt communication of the diagnostic results to government officials. A new diagnostic paradigm that consists of miniaturized extractor and qPCR instruments (EZextractor and EZcycler MiniQ), designed for mobile, on-site testing has been compared with a platform of benchtop instruments (QIAGEN RNeasy and QuantStudio 5) for detecting inactivated H5 avian influenza virus (AIV) spiked in raw milk samples. Two sets of experiments were performed: 1) 15 raw milk samples, obtained from 15 different farms, diluted with phosph...

Abstract The global spread of the A/goose/Guangdong/1/96-lineage H5N1 highly pathogenic avian influenza (HPAI) viruses is accompanied by an expanded host range and the establishment of sustained viral transmission among dairy cattle . To evaluate if the evolving H5N1 viruses have changed tissue tropism over time, we compared the binding patterns of recombinant hemagglutinin (HA) proteins derived from clade 1 (A/Vietnam/1203/04, H5VN) and circulating clade 2.3.4.4b viruses detected from a wild bird (A/Eurasian Teal/Hong Kong/AFCD-HKU-23-14009-01020/2023, H5HK) and dairy cattle (A/bovine/Ohio/B24OSU-439/2024, H5OH). The HA protein of A(H1N1)pdm09 virus was included for comparison. Using bio-layer interferometry, H1 protein preferentially bound to the 2,6-linked sialoside 6'SLNLN while H5 proteins preferentially bound to the 2,3-linked sialoside 3'SLN. H5OH showed higher binding affinity to 3'SLN than H5HK and H5VN. The attachment pattern of H1 and H5 proteins to the respirato...

ABSTRACT A panzootic of highly pathogenic avian influenza (HPAI) H5N1 viruses from clade 2.3.4.4b has triggered a multistate outbreak in US dairy cattle and an unknown number of human infections . HPAI viruses are handled in specialized biocontainment facilities. Ethical considerations limit certain evolution experiments aimed at assessing viral resistance to potential therapeutics. We have developed a replicating recombinant vesicular stomatitis virus (rVSV) where we replaced its glycoprotein with the hemagglutinin (HA) and neuraminidase (NA) genes of a 2.3.4.4b H5N1 virus (rVSV-H5N1dc2024), which enables these experiments to be performed under standard biosafety considerations. This virus grows to high titers and encodes a fluorescent reporter to track infection. We demonstrate the utility of rVSV-H5N1dc2024 in neutralization experiments, the evaluation of antibody escape, and the characterization of resistance mutations to NA inhibitors. rVSV-H5N1dc2024 or similar viruses may accele...

  New human cases {2}:  -- From 23 April to 27 May 2025, based on reporting date, the detection of influenza A( H5N1 ) in three humans, the detection of influenza A( H9N2 ) virus in eight humans and the detection of influenza A( H10N3 ) in one human were reported officially.  -- Circulation of influenza viruses with zoonotic potential in animals:  - High pathogenicity avian influenza (HPAI) outbreaks in poultry and non-poultry animals 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}  -- Risk assessment {5}:  - Sustained human to human transmission has not been reported in these events. Based on information available at the time of the risk assessment , the overall public health risk from currently known influenza viruses circulating at the human-animal interface has not c...

Abstract The 2024 outbreak of highly pathogenic avian influenza virus (HPAIV) H5N1 in U.S. dairy cattle presented an unprecedented scenario where the virus infected bovine mammary glands and was detected in milk , raising serious concerns for public health and the dairy industry. Unlike previously described subclinical influenza A virus (IAV) infections in cattle, H5N1 infection induced severe clinical symptoms , including respiratory distress, mastitis, and abnormal milk production . To understand the host immune responses and changes, particularly in the mammary gland, we performed single-cell RNA sequencing analysis on bovine milk somatic cells (bMSCs) in vitro exposed to an H5N1 isolate from an infected dairy farm. We identified ten distinct cell clusters and observed a shift toward type-2 immune responses , characterized by T cells expressing IL13 and GATA3 , and three different subtypes of epithelial cells based on the expression of genes associated with milk production. Our stud...

The samples collected in two (2) wild bird species : Red Shank (Tringa totanus) and Arctic Warbler (Phylloscopus borealis), that tested positive for Notifiable Avian Influenza Subtype H5N1 were part of the regular wildlife disease surveillance activity being conducted by the wetland park. In response, additional samples were collected from wild birds, and all tested negative for Avian Influenza. Comprehensive surveillance and sample collection efforts in the surrounding domestic poultry population also confirmed no presence of Avian Influenza. Source: WOAH,  https://wahis.woah.org/#/in-review/6523 ____

HPAI H5N1 confirmed in backyard poultry farm with approx. 190 birds (laying hens). Susupicion date 27/05/2025 - some birds with neurological signs, one dead. Laboratory diagnosis confirmed at the Latvian National Reference Laboratory for avian influenza. Source: WOAH,  https://wahis.woah.org/#/in-review/6528 ____

Highlight Brazil’s first confirmed H5N1 outbreak in commercial poultry marks a critical shift in South America’s avian influenza landscape. The event calls for strengthened coordination between animal and human health sectors, improved border surveillance, and early-warning systems to reduce zoonotic risk in regions with growing poultry production and international connectivity. Source: Journal of Travel Medicine,  https://academic.oup.com/jtm/advance-article-abstract/doi/10.1093/jtm/taaf050/8153894?redirectedFrom=fulltext ____

Abstract We confirmed influenza A virus (IAV) by PCR in serum from 18 cows on 3 affected dairy farms in California, USA . Our findings indicate the presence of viremia and might help explain IAV transmission dynamics and shedding patterns in cows. An understanding of those dynamics could enable development of IAV mitigation strategies. Source: US Centers for Disease Control and Prevention,  https://wwwnc.cdc.gov/eid/article/31/7/25-0134_article ____

  {Excerpt} Time Period: May 18, 2025 - May 24, 2025 -- H5 Detection :  17 sites ( 5.0% ) - No Detection :  322 sites ( 95.0% ) - No samples in last week :  116 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/bird-flu/h5-monitoring/index.html ____