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 Influenza A (H3N2) viruses are historically responsible for the 1968 Hong Kong flu pandemic. Since then, H3N2 has continued to circulate as a seasonal influenza virus in humans. Public health concerns were raised in 2022 when human infections with novel reassortant H3N8 influenza viruses originating from chickens were first reported in China . Here, we conducted a systematic surveillance of H3 avian influenza viruses (AIVs) circulating in poultry and assessed the public health risk of emergent H3 reassortants. We found that H3 AIVs were prevalent in both ducks and chickens . Notably, in December 2022, a novel chicken-derived H3N3 subtype virus was identified, which gradually replaced the previously predominant H3N8 virus and became prevalent in chickens. Genetic analysis demonstrated that the novel H3N3 virus is a triple-reassortment strain with the H3 gene segment from chicken H3N8 virus, the N3 gene segment from the H10N3 virus , and internal gene segments derived from H9N2 ...

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...

ABSTRACT Several emerging influenza viruses, including H7N9 and H5N6 viruses, trace their origins to reassortment with H9N2 viruses that contributed internal gene segments. However, the evolutionary constraints governing the reassortment of H9N2 viruses remain unknown. In seasonal human influenza A viruses, gene segments coevolve at both the nucleotide and amino acid levels. Here, we demonstrate that evolutionary relationships between gene segments, including polymerase subunits in human H3N2 viruses, differ from avian H9 viruses . Avian H9 viruses were characterized by little coevolution between gene segments or between polymerase subunits. Strikingly, protein trees built from avian H9 polymerase subunits diverge despite known functional constraints on polymerase evolution. The evolutionary divergence observed between gene segments of avian H9 viruses was consistent across isolates from different continents, suggesting that coevolution between H9 gene segments is not dependent on regi...

  {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 ____

Highlights •  Systematic and routine monitoring antigenic drift and shift of AIV in wild birds and poultry is needed. •  Community-based surveillance is key for improving NiV case detection. •  Integrated surveillance across One Health sectors is required. •  Lab upgrades to BSL-3 are needed for enhanced biosafety and diagnostics. Abstract Nipah and avian influenza viruses (NiV and AIV) are priority zoonotic pathogens in Bangladesh and are also important globally because of their pandemic potential . To understand current strengths, areas for improvement, and opportunities to enhance preparedness for NiV and AIV in Bangladesh, as part of the USAID STOP Spillover program , 47 relevant stakeholders were surveyed, and two country leads of the primary surveillance systems were interviewed. Data was collected focusing on four different areas: research projects, surveillance systems, laboratories, and outbreak risk management systems. Despite progress in recent years, our ...

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 ____

 A wild Peregrine falcon in Kagoshima Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6545 ____

Abstract Since 2021, the novel H10N3 has caused four cases of human infection in China, the most recent of which occurred in December 2024 , posing a potential threat to public health. Our previous studies indicated that several avian H10N3 strains are highly pathogenic in mice and can be transmitted between mammals via respiratory droplets without prior adaptation. By analyzing the genome sequence , we found that these H10N3 viruses carry the PB2-E627V mutation , which is becoming increasingly common in several subtypes of avian influenza viruses (AIV); however, its mechanism in mammalian adaptation remains unclear. Using a reverse genetics system , we investigated the role of PB2-E627V in the adaptation of H10N3 to mammals and poultry. Our findings demonstrate that the PB2-E627V mutation is critical for the high pathogenicity of novel H10N3 in mice and its ability to be transmitted through the air among mammals . Additionally, we found that the role of PB2-627 V in promoting AIV adap...

  BMC Pediatr ALRASHED R, Almeshawi I, Alshammari A, Alhamoud W, et al Burden of bronchiolitis post-COVID-19 pandemic in children less than 2 years old in 2021-2024: experience from a tertiary center in Saudi Arabia. BMC Pediatr. 2025;25:453. PubMed           Abstract available BIGLARI HN, Ahmadi A, Alidousti K, Pouredalati M, et al Growth in the first two years in children born to mothers infected with COVID-19 during pregnancy: a cohort study. BMC Pediatr. 2025;25:448. PubMed           Abstract available CHENG J, Wu Y, Ma H, Tang M, et al C-reactive protein and serum amyloid A protein as complementary biomarkers in differentiating viral and bacterial community-acquired pneumonia in children. BMC Pediatr. 2025;25:445. PubMed           Abstract available J Gen Virol CAPELASTEGUI F, Goldhill DH H5N1 2.3.4.4b: a review of mammalian adaptations and risk of pandemic e...

  {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 Since multiple and unpredicted influenza viruses cause seasonal epidemics and even high-risk pandemics , developing a universal influenza vaccine is essential to provide broad protection against various influenza subtypes. Combined with the mRNA lipid nanoparticle-encapsulated (mRNA-LNP) vaccine platform and chimeric immunogen strategy , we developed a novel cocktail mRNA vaccine encoding chimeric HAs (cH5/1-BV, cH7/3) and intact M2 (termed Fluaxe), which confers broad protection against major circulating IAVs and IBVs , as well as highly pathogenic avian influenza . Two-dose intramuscular immunization of Fluaxe in mice elicited cross-reactive neutralizing antibodies , T cell responses, and long-lived immunity, resulting in robust protection against multiple lethal influenza virus infections and severe acute lung injuries . In particular, intramuscular administration stimulated systemic immunity together with a prominent lung tropism of memory cells . Moreover, Fluaxe immuniza...

Abstract Nationwide surveillance of avian influenza viruses (AIVs) in live poultry markets across China has occurred since 2014, providing a resource for AIV prevalence and genetic diversity studies . Here we report that 3,237 of 18,425 samples from poultry were AIV positive (17.57%) between 2019 and 2023, with H9N2 being the dominant subtype . We developed an automated phylogeny-based nomenclature system to classify genetic clades of the dominant H9N2 lineage, the BJ94 lineage. Using this model, we found that ten haemagglutinin (HA) sub-subclades cocirculated in poultry and showed antigenic variation. In addition, 99.46% and 96.17% of H9N2 AIVs in 2021–2023 possessed human-receptor binding-related HA-L226 and human MxA-resistance-related NP-N52 mutations , respectively. H9N2 strains with these two mutations preferred human-type receptors and increased replication in human cells in vitro, regardless of the presence of PB2-V/K/E627. Moreover, H9N2 AIVs containing HA-L226, PB2-V/K627 and...

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...