Recent evidence findings

Evidence-grounded Research Brief · Past 3 months 129

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34 source articles 14 hosts 10 countries
Publication date Category / type Key finding PMID
2026-10-08 Zoonotic Surveillance Virus Isolation An H9N2 avian influenza virus was isolated from a chicken in Shandong Province, China, in March 2019. 42849636
2026-10-08 Zoonotic Surveillance Virus Isolation An H9N2 avian influenza virus was isolated from a pig in Shandong Province, China, in March 2019. 42849636
2026-10-08 Genomic Evolution Recombination or Reassortment Two H9N2 viruses shared an identical reassortant genome: HA/NA from Y280-like, PB2/M from G1-like, and PB1/PA/NP/NS from SH/F98-like lineages. 42849636
2026-10-08 Experimental Infection Pathogenicity Experiment Two H9N2 viruses caused interstitial pneumonia and replicated in lungs and nasal turbinates of mice without significant weight loss or death and without detectable dissemination to other organs. 42849636
2026-10-08 Functional Mechanism Molecular Adaptation Both H9N2 isolates carried amino acid substitutions previously linked to mammalian adaptation, receptor binding, viral replication, and antigenic variation. 42849636
2026-10-08 Genomic Evolution Phylogenetic Evolution Both H9N2 isolates were classified as genotype G57 and closely related to H9N2 viruses previously detected in environmental samples in Jiangsu Province. 42849636
2026-10 Zoonotic Surveillance Viral Detection Highly pathogenic avian influenza H5N1 virus was detected in dead waterfowl at Ibirapuera Park, São Paulo, Brazil, in 2025. 42811438
2026-10 Zoonotic Surveillance Virus Isolation Fifty-six influenza A viruses were isolated from swine in Vietnam during 2020–2024, comprising 21 H1N1, 31 H1N2, and 4 H3N2 isolates. 42811277
2026-10 Experimental Infection Pathogenicity Experiment Experimental infection of breeding ducks with an H6N6 avian influenza virus caused significant reproductive tract damage and decreased egg production. 42385378
2026-10 Experimental Infection Host Range Experiment In vivo challenge showed the H6N6 avian influenza virus infected mice, SPF chickens, and young Muscovy ducks, causing mild lesions. 42385378
2026-10 Genomic Evolution Recombination or Reassortment The isolated H6N6 avian influenza virus is a triple-reassortant derived from three distinct genetic clades. 42385378
2026-10 Zoonotic Surveillance Virus Isolation A novel H6N6 avian influenza virus was successfully isolated from affected breeding duck farms. 42385378
2026-10 Genomic Evolution Phylogenetic Evolution Phylogenetic analysis found multiple co-circulating H1 and H3 clades in swine and showed three H1 clades persisted exclusively in Vietnam for up to 12 years. 42811277
2026-10 Genomic Evolution Recombination or Reassortment The detected H5N1 virus in São Paulo was a reassortant derived from locally circulating LPAI viruses and highly pathogenic North American lineages. 42811438
2026-10 Functional Mechanism Molecular Adaptation The H6N6 avian influenza virus isolate carries HA substitutions A138S and A222V, molecular changes implicated in adaptation. 42385378
2026-09-29 Functional Mechanism Molecular Adaptation The combined neuraminidase mutations N70S and Y155H in H9N2 increase resistance to oseltamivir and zanamivir compared to single mutants, while remaining sensitive to peramivir. 42810520
2026-09-29 Experimental Infection Pathogenicity Experiment H9N2 avian influenza viruses with combined N70S and Y155H neuraminidase mutations caused high pathogenicity in BALB/c mice without prior adaptation. 42810520
2026-09-29 Genomic Evolution Phylogenetic Evolution Phylogenetic analysis indicates that HA A227E and NA S369N substitutions were acquired in swine prior to the emergence of H1N1pdm09 in humans. 42776754
2026-09-29 Functional Mechanism Molecular Adaptation In H1N1pdm09-related swine viruses, HA A227E reduces receptor binding and NA S369N in the 2SBS reduces NA cleavage, jointly adjusting the HA–NA balance linked to host-range adaptation before the 2009 pandemic emergence. 42776754
2026-09-29 Functional Mechanism Molecular Adaptation NAI resistance-associated neuraminidase positions in H9N2 viruses from China (1998–2024) include N70S, E119A/D/G/V, Q133K, Q136A, D151E, Y155H, I222V, R224K, E276D, R292K, N294S, and R371K. 42810520
2026-09-29 Experimental Infection Pathogenicity Experiment Neuraminidase inhibitors showed limited in vivo protective effect against H9N2 virus with combined N70S/Y155H mutations, potentially due to inability to ameliorate excessive inflammatory responses. 42810520
2026-09-28 Experimental Infection Host Range Experiment Full-length BC24 H5N1 hemagglutinin expressed in human A549 cells mediates membrane fusion, though at lower levels than prior H5 HAs. 42806028
2026-09-22 Genomic Evolution Recombination or Reassortment Most H5N1 and H5N9 genotypes detected in Korea in 2025–2026 are reassortants between East Asian clade 2.3.4.4b H5N1 HPAIVs (since 2022) and low-pathogenicity avian influenza viruses from wild birds. 42772571
2026-09-22 Zoonotic Surveillance Viral Detection Clade 2.3.4.4b H5N1 HPAIV was detected in poultry and wild birds in Korea during the 2025–2026 winter season, with numerous outbreaks and cases reported. 42772571
2026-09-22 Experimental Infection Pathogenicity Experiment In young ducks, H5N1 caused rapid mortality while H5N9 produced limited clinical signs without mortality. 42772571
2026-09-22 Zoonotic Surveillance Viral Detection Clade 2.3.4.4b H5N9 HPAIV was detected in poultry and wild birds in Korea during the 2025–2026 winter season. 42772571
2026-09-22 Zoonotic Surveillance Viral Detection Clade 2.3.4.4b H5N6 HPAIV was detected in poultry and wild birds in Korea during the 2025–2026 winter season. 42772571
2026-09-22 Experimental Infection Experimental Transmission H5N9 transmitted to all contact ducks in a controlled contact-transmission experiment. 42772571
2026-09-22 Experimental Infection Experimental Transmission H5N1 transmitted to all contact ducks in a controlled contact-transmission experiment. 42772571
2026-09-10 Zoonotic Surveillance Virus Isolation Six H1N1 viruses belonging to the G4 genotype were isolated from pigs with respiratory disease in six Chinese provinces during 2023–2025. 42797971
2026-09-10 Genomic Evolution Phylogenetic Evolution Phylogenetic analysis placed six 2023–2025 swine H1N1 isolates in the G4 genotype with EA-lineage HA/NA, pdm09-derived PB2/PB1/PA/NP/M, and a triple‑reassortant NS segment. 42797971
2026-09 Functional Mechanism Molecular Adaptation H5N1 clade 2.3.4.4b carries an HA multibasic cleavage site and avian-specific receptor-binding residues (Q224, G226), supporting high pathogenicity and strong avian receptor affinity. 42767772
2026-09 Genomic Evolution Recombination or Reassortment An A(H5N1) clade 2.3.4.4b virus in Bangladesh is a reassortant with NA, PB1, NP, MP, and NS derived from contemporary A(H5N1) of ducks in LBMs, while PB2 and PA originate from LPAI viruses. 42767772
2026-09 Genomic Evolution Phylogenetic Evolution The HA gene of the Bangladesh HPAI A(H5N1) clade 2.3.4.4b virus clusters with recent LBM-origin strains from Bangladesh, with an MRCA around July 2023. 42767772
2026-09 Zoonotic Surveillance Serological Evidence An exposed domestic cat (CAT 2) seroconverted with antibodies against influenza A NP and H5/N1 antigens after initial PCR negativity. 42679799
2026-09 Zoonotic Surveillance Viral Detection HPAIV H5N1 clade 2.3.4.4b was detected in a domestic cat in Italy during an avian influenza outbreak on the same farm. 42679799
2026-09 Zoonotic Surveillance Virus Isolation Avian influenza virus A(H5N1) clade 2.3.4.4b was isolated from commercial quail during an outbreak in Bangladesh. 42767772
2026-09 Transmission Evidence Outbreak Investigation An outbreak investigation identified H5N1 clade 2.3.4.4b infection in domestic cats associated with a concurrent backyard poultry HPAI outbreak in Italy, with one fatal feline case and one seroconversion in an exposed cat. 42679799
2026-09 Zoonotic Surveillance Viral Detection A reassortant A(H5N1) clade 2.3.4.4b virus was detected in commercial poultry in Bangladesh, indicating ongoing circulation. 42767772
2026-09 Genomic Evolution Phylogenetic Evolution The PB2 gene of the A(H5N1) clade 2.3.4.4b virus carries a rare I147T substitution while mammalian-adaptive markers E627K and D701N are absent. 42767772
2026-09 Functional Mechanism Molecular Adaptation The feline H5N1 clade 2.3.4.4b isolate harbored PB2-E627K, a polymerase mutation linked to mammalian adaptation and increased pathogenicity. 42679799
2026-08-26 Zoonotic Surveillance Serological Evidence In 2025 serosurveillance of 400 Japanese horses found no detectable H5N1 antibodies by HI, with 399/400 cELISA-negative and one doubtful sample. 42648659
2026-08-21 Genomic Evolution Recombination or Reassortment H9N2 isolate ZHY0417A11 is a multigenic reassortant acquiring PB1 from H3N8, PA and PB2 from H3N3, NS from H10N3, and retaining an H9N2 HA/NA/NP backbone, with an M gene nearly identical to a human H3N8 isolate. 42655736
2026-08-21 Zoonotic Surveillance Virus Isolation Two H9N2 avian influenza virus isolates (ZHY1022B2 and ZHY0417A11) were recovered from quail flocks in Hebei, China during 2024–2025. 42655736
2026-08-21 Genomic Evolution Phylogenetic Evolution HA genes of the two H9N2 quail isolates fall within subclade B4.7.2 and segregate into subgroups B4.7.2.2 and B4.7.2.1. 42655736
2026-08-21 Functional Mechanism Molecular Adaptation H9N2 isolates carry HA mammalian-adaptive markers H191N, A198V, and Q234L. 42655736
2026-08-10 Experimental Infection Host Range Experiment H5TX Q226L binds human-type receptors but requires additional mutations to bind human tracheal tissue in tissue-based assays. 42573239
2026-08-07 Genomic Evolution Phylogenetic Evolution HA phylogeny assigns the 2023 Pakistani H9N2 isolates to the G5.3.2 (formerly B2) sub-lineage within the G1 Eurasian lineage. 42566313
2026-08-07 Zoonotic Surveillance Virus Isolation Five H9N2 avian influenza virus isolates were obtained from poultry in Pakistan between January and March 2023. 42566313
2026-08-07 Genomic Evolution Phylogenetic Evolution All eight gene segments of the 2023 Pakistani H9N2 isolates are closely related to prior Pakistani strains with no recent reassortment, consistent with localized persistence and drift. 42566313
2026-08-07 Functional Mechanism Receptor Usage G1-lineage H9N2 isolates from Pakistan bind both α2,3- and α2,6-linked sialic acid receptors, with stronger affinity for α2,6. 42566313
2026-08-07 Functional Mechanism Molecular Adaptation H9N2 isolates carried several mammalian-adaptive mutations in internal genes, indicating potential cross-species transmission risk. 42566313
2026-08-03 Transmission Evidence Outbreak Investigation During the 2023 HPAI H5N1 outbreak in Chubut, Argentina, 3 South American sea lions and 1 southern elephant seal stranded and were investigated, with HPAI H5 clade 2.3.4.4b confirmed by PCR and sequencing. 42548173
2026-08-03 Zoonotic Surveillance Viral Detection HPAI virus was detected within fetal tissues associated with necrotizing placentitis in a sea lion. 42548173
2026-08 Zoonotic Surveillance Viral Detection In summer 2022, HPAIVs including EA-2020-C (H5N1), EA-2021-AB (H5N1), and EA-2021-I (H5N5) were first detected in the High Arctic in a glaucous gull and great skuas on Svalbard and Jan Mayen. 42606890
2026-08 Functional Mechanism Molecular Adaptation In H7N9 virus, the PA-X I94V mutation enhances viral polymerase activity and replication in mammalian cells. 42090884
2026-08 Experimental Infection Pathogenicity Experiment The PA/PA-X I94V mutation increases pathogenicity and viral fitness of H7N9 influenza A virus in mice. 42090884
2026-08 Genomic Evolution Recombination or Reassortment Shandong poultry H9N2 isolates are reassortants combining G1-like (PB2, M), SH/F98-like (PB1, PA, NP, NS), and Y280-like (HA, NA) lineage segments. 42184734
2026-08 Genomic Evolution Phylogenetic Evolution Multiple distinct HPAIV genotypes detected in Svalbard and Jan Mayen indicate repeated and independent introductions into the High Arctic. 42606890
2026-08 Genomic Evolution Recombination or Reassortment H5N8 viruses from Egyptian waterfowl shifted from genotype G1 (2018 duck strains) to genotype G4 in 2022 due to segment reassortment across the 8 gene segments. 41498130
2026-08 Functional Mechanism Molecular Adaptation H5N8 strains from 2022 possessed internal gene markers associated with mammalian adaptation, including PB2 504V, PA 127V and 672L, and PB1 133G. 41498130
2026-08 Zoonotic Surveillance Viral Detection RT-qPCR detected H5N8 HPAI in 13 duck flocks and 11 geese flocks among 30 symptomatic waterfowl flocks; sampling was from Menoufia governorate, Egypt in 2022. 41498130
2026-08 Genomic Evolution Phylogenetic Evolution Recent sequence analysis shows high variation at PA/PA-X site 94 in H5N1 and H7N9, with the PA-X I94V mutation becoming prevalent in recent human H7N9 viruses. 42090884
2026-08 Functional Mechanism Molecular Adaptation The PA-X I94V mutation in H7N9 modulates PA-X–mediated host shutoff, inhibiting antiviral and cell death–related responses. 42090884
2026-08 Experimental Infection Pathogenicity Experiment The PA/PA-X I94V mutation attenuates virulence of H7N9 influenza A virus in chickens. 42090884
2026-08 Experimental Infection Pathogenicity Experiment Three poultry-derived H9N2 isolates replicated efficiently in mouse lungs without causing mortality, with CK/SD/TA1016/22 showing higher replication and more severe lung lesions. 42184734
2026-08 Functional Mechanism Molecular Adaptation H9N2 isolates carried human-adapted HA receptor-binding mutations and mammalian-adaptation mutations in polymerase and other genes, indicating enhanced mammalian adaptation potential. 42184734
2026-08 Zoonotic Surveillance Virus Isolation Eight H9N2 avian influenza virus strains were successfully isolated from RT‑qPCR–positive chicken samples in Shandong Province, China. 42184734
2026-08 Experimental Infection Pathogenicity Experiment In PA-X–deficient H7N9 virus, adding the PA I94V mutation has no obvious effect on viral fitness in mice and chickens, implicating PA-X I94V in virulence modulation. 42090884
2026-08 Functional Mechanism Molecular Adaptation Brain-derived H5N8 isolates carried HA substitutions F244L, I248S, and K234R relative to tracheal isolates, suggesting adaptation linked to neurotropism. 41498130
2026-08 Zoonotic Surveillance Viral Detection RT-qPCR detected H9N2 avian influenza virus in diseased chickens in Shandong Province during 2021–2023, with 10 positives out of 192 samples. 42184734
2026-08 Genomic Evolution Phylogenetic Evolution HA phylogeny shows 2022 Egyptian H5N8 clade 2.3.4.4b isolates cluster with Russian and European-like strains, with mutations linked to antigenic drift and adaptation. 41498130
2026-08 Genomic Evolution Phylogenetic Evolution Co-circulation of genetically distinct HPAIV strains in high-density Arctic bird areas suggests local amplification and subsequent dissemination along migratory flyways. 42606890
2026-08 Genomic Evolution Phylogenetic Evolution Phylogenetic analysis of poultry-derived H9N2 isolates from Shandong showed a multi-lineage genome composition with PB2 and M from G1-like, PB1/PA/NP/NS from SH/F98-like, and HA/NA from Y280-like lineages, indicating reassortment. 42184734
2026-08 Functional Mechanism Molecular Adaptation Patient-derived H5N1 HA mutations E190D and Q226H abolish receptor binding and thus hinder molecular adaptation toward human-type receptor specificity. 42139887
2026-08 Zoonotic Surveillance Virus Isolation H5N8 HPAI viruses were isolated from waterfowl in Egypt, yielding brain-derived and tracheal isolates. 41498130
2026-08 Zoonotic Surveillance Viral Detection In 2023, HPAIVs were detected in a broader range of bird species and retrospectively in an Atlantic walrus, with genotypes EA-2020-C (H5N1), EA-2021-I (H5N5), and EA-2022-BB (H5N1). 42606890
2026-07-30 Zoonotic Surveillance Virus Isolation Seven H6N1 avian influenza viruses were isolated from wild bird fecal samples in Mongolia during 2022–2024. 42533206
2026-07-30 Experimental Infection Pathogenicity Experiment H9N2 replicated effectively in lungs and nasal turbinates of BALB/c mice without prior adaptation. 42655013
2026-07-30 Experimental Infection Host Range Experiment H9N2 avian influenza virus replicated and spread more efficiently in chickens than in ducks in controlled poultry infection studies. 42655013
2026-07-30 Genomic Evolution Phylogenetic Evolution H6N1 viruses from Mongolia and the Republic of Korea show strong phylogeographic connectivity within the Northeast Asian lineage (Bayes factor > 100). 42533206
2026-07-30 Zoonotic Surveillance Virus Isolation H6N1 viruses were isolated from fecal samples of wild birds and domestic ducks in the Republic of Korea between September 2023 and April 2024. 42533206
2026-07-30 Experimental Infection Experimental Transmission H9N2 avian influenza virus was transmitted to contact ducks more efficiently from infected chickens than from ducks to ducks under a controlled contact-transmission setup. 42655013
2026-07-30 Functional Mechanism Molecular Adaptation H6N1 viruses show HA–NA co-adaptation consistent with a functional balance between HA receptor binding and NA enzymatic activity. 42533206
2026-07-30 Genomic Evolution Phylogenetic Evolution H6N1 HA and NA genes from Mongolia and the Republic of Korea cluster in the Northeast Asian lineage and diverged into two regional subclades around 2016–2017 with ladder-like, geographically structured phylogenies. 42533206
2026-07-30 Experimental Infection Pathogenicity Experiment Inoculated chickens and ducks showed upregulated PRR and cytokine mRNA in lungs, with lower fold increases in ducks than chickens following H9N2 infection. 42655013
2026-07-30 Genomic Evolution Phylogenetic Evolution H6N1 surface gene evolution is driven mainly by antigenic drift with restricted regional intra- and inter-clade reassortment, indicating HA–NA co-adaptation. 42533206
2026-07-30 Genomic Evolution Phylogenetic Evolution Phylogenetic analysis placed the H9N2 isolate’s HA in the B4.7 lineage while the other seven segments were Eurasian, indicating complex reassortment across regions in China. 42655013
2026-07-30 Zoonotic Surveillance Virus Isolation One H9N2 avian influenza virus was isolated from chickens in Jiangsu Province, China in March 2025. 42655013
2026-07-30 Functional Mechanism Molecular Adaptation The H9N2 isolate harbors key amino acid substitutions that may enhance viral polymerase activity and replication efficiency in mice. 42655013
2026-07-28 Zoonotic Surveillance Serological Evidence Neutralizing antibodies to H5N1 were detected in 3 of 12 domestic cats sampled within 2 km of dairy farms in California, USA. 42520787
2026-07-28 Zoonotic Surveillance Reservoir Ecology Among domestic cats in California, proximity to dairy farms was a significant ecological risk factor associated with H5N1 seropositivity. 42520787
2026-07-26 Functional Mechanism Receptor Usage Emerging H5N1 clade 2.3.4.4b binds human MHC-II HLA-DR and can mediate sialic acid–independent cell entry, unlike historical H5 lineages. 42539232
2026-07-26 Experimental Infection Host Range Experiment H5N1 clade 2.3.4.4b hemagglutinin binds human MHC-II (HLA-DR) and enables sialic acid–independent entry, with binding to primary human immune cells varying by MHC-II expression and HLA-DR allele. 42539232
2026-07-26 Transmission Evidence Outbreak Investigation HPAI H5N1 clade 2.3.4.4b is reported as causing a multi-species outbreak affecting wild birds, poultry, multiple mammalian species, and humans. 42539232
2026-07-22 Genomic Evolution Recombination or Reassortment H3N3 isolates were reassortants with HA from the novel H3N8 AIV lineage, NA from H10N3 AIV, and internal genes from H9N2 AIV. 42486182
2026-07-22 Genomic Evolution Recombination or Reassortment An H3N8 isolate was a triple-reassortant with Eurasian avian H3, North American avian N8, and H9N2-derived internal genes. 42486182
2026-07-22 Zoonotic Surveillance Serological Evidence HI assays showed no cross-reactivity between the novel H3 avian influenza viruses and H5, H7, or H9 avian influenza viruses. 42486182
2026-07-22 Experimental Infection Pathogenicity Experiment A representative H3N8 avian influenza virus infected BALB/c mice without prior adaptation, replicating mainly in the upper respiratory tract with limited extrapulmonary dissemination. 42486182
2026-07-22 Functional Mechanism Molecular Adaptation H3 avian influenza isolates harbored PB2 L89V, PB2 I292V, and PB1 H436Y substitutions previously linked to enhanced mammalian adaptation. 42486182
2026-07-22 Zoonotic Surveillance Virus Isolation One H3N8 and ten H3N3 avian influenza viruses were isolated from poultry samples in China. 42486182
2026-07-22 Genomic Evolution Phylogenetic Evolution Phylogenetic analysis indicated the H3N3 isolates are reassortants with HA derived from the novel H3N8 lineage, NA from H10N3, and internal genes from H9N2. 42486182
2026-07-22 Genomic Evolution Phylogenetic Evolution Phylogenetic whole‑genome analysis showed the H3N8 isolate is a triple‑reassortant with a Eurasian avian H3 gene, a North American avian N8 gene, and H9N2‑derived internal genes. 42486182
2026-07-21 Zoonotic Surveillance Viral Detection HPAI H5N1 viral RNA was detected in organ samples from domestic and wild birds in Romania (2017–2024) using real-time RT-PCR, with subsequent sequencing of PB1 and PB2 fragments. 42515095
2026-07-21 Genomic Evolution Phylogenetic Evolution Romanian H5N1 isolates cluster within Eurasian H5N1 lineages and are closely related to contemporary strains from Eastern Europe and Russia. 42515095
2026-07-18 Experimental Infection Host Range Experiment Intramammary exposure to bovine-derived H5N1 causes productive infection in lactating sows despite prior vaccination. 42523357
2026-07-18 Experimental Infection Pathogenicity Experiment Intramammary inoculation with influenza A(H5N1) in lactating sows caused mammary lesions and antigen-positive tissue with sustained viral RNA in milk but no overt clinical disease or respiratory involvement. 42523357
2026-07-18 Zoonotic Surveillance Viral Detection Viral RNA from influenza A(H5N1) was detected and shed persistently in the milk of intramammarily inoculated lactating sows. 42523357
2026-07-18 Zoonotic Surveillance Serological Evidence In experimentally inoculated lactating sows, neutralizing antibody responses against influenza A(H5N1) developed, indicating immune exposure. 42523357
2026-07-18 Experimental Infection Experimental Transmission Piglets co-housed with intramammary-inoculated lactating sows showed sporadic oral viral RNA positivity that mirrored milk viral kinetics, indicating limited vertical transmission to piglets. 42523357
2026-07-17 Functional Mechanism Receptor Usage Ailong virus uses human ephrin B2 (EFNB2) and ephrin B3 (EFNB3) as functional receptors. 42467734
2026-07-17 Zoonotic Surveillance Viral Detection Avian influenza viruses were consistently detected from wild birds via annual sampling around Izembek National Wildlife Refuge, Alaska since 2011. 42469424
2026-07-17 Zoonotic Surveillance Viral Detection H5 subtype highly pathogenic avian influenza viruses were detected in the Pacific Flyway of North America in 2014 and 2022. 42469424
2026-07-17 Experimental Infection Pathogenicity Experiment In human bronchial epithelial Calu-3 cells, H5N1 clade 2.3.4.4b viruses induced moderate type I interferon and proinflammatory responses, lower than A(H1N1)pdm09 and H5N1 clade 1. 42466872
2026-07-17 Genomic Evolution Recombination or Reassortment Reassortment between HPAIVs and LPAIVs produced novel HPAIV genotypes and one LPAIV carrying an HPAIV gene segment in southwestern Alaska. 42469424
2026-07-17 Zoonotic Surveillance Viral Detection During 14 years of AIV surveillance in southwestern Alaska, detected virus prevalence peaked during periods of HPAIV introduction. 42469424
2026-07-17 Zoonotic Surveillance Reservoir Ecology Avian influenza viruses were consistently detected in wild birds in southwestern Alaska, with frequent intercontinental viral dispersal observed among this host population. 42469424
2026-07-17 Genomic Evolution Phylogenetic Evolution Following 2022 introductions of HPAIVs, the proportion of Eurasian-lineage gene segments in avian influenza viruses from wild birds in southwestern Alaska increased. 42469424
2026-07 Functional Mechanism Molecular Adaptation NS1-A53D enhances HA stability while maintaining receptor binding specificity, compensating for reduced receptor-binding affinity caused by HA mutations in H1N1 canine influenza virus. 42176433
2026-07 Experimental Infection Host Range Experiment Seasonal influenza A H1N1, H3N2, influenza B, MERS-CoV, and SARS-CoV productively replicated and infected human bronchial tissues in an ex vivo model. 42397692
Evidence-grounded Research Brief · Past month 39

Synthesizing linked evidence and source literature...

Generating an evidence-grounded brief with GPT-5...
10 source articles 7 hosts 4 countries
Publication date Category / type Key finding PMID
2026-10-08 Zoonotic Surveillance Virus Isolation An H9N2 avian influenza virus was isolated from a chicken in Shandong Province, China, in March 2019. 42849636
2026-10-08 Zoonotic Surveillance Virus Isolation An H9N2 avian influenza virus was isolated from a pig in Shandong Province, China, in March 2019. 42849636
2026-10-08 Genomic Evolution Recombination or Reassortment Two H9N2 viruses shared an identical reassortant genome: HA/NA from Y280-like, PB2/M from G1-like, and PB1/PA/NP/NS from SH/F98-like lineages. 42849636
2026-10-08 Experimental Infection Pathogenicity Experiment Two H9N2 viruses caused interstitial pneumonia and replicated in lungs and nasal turbinates of mice without significant weight loss or death and without detectable dissemination to other organs. 42849636
2026-10-08 Functional Mechanism Molecular Adaptation Both H9N2 isolates carried amino acid substitutions previously linked to mammalian adaptation, receptor binding, viral replication, and antigenic variation. 42849636
2026-10-08 Genomic Evolution Phylogenetic Evolution Both H9N2 isolates were classified as genotype G57 and closely related to H9N2 viruses previously detected in environmental samples in Jiangsu Province. 42849636
2026-10 Zoonotic Surveillance Viral Detection Highly pathogenic avian influenza H5N1 virus was detected in dead waterfowl at Ibirapuera Park, São Paulo, Brazil, in 2025. 42811438
2026-10 Zoonotic Surveillance Virus Isolation Fifty-six influenza A viruses were isolated from swine in Vietnam during 2020–2024, comprising 21 H1N1, 31 H1N2, and 4 H3N2 isolates. 42811277
2026-10 Experimental Infection Pathogenicity Experiment Experimental infection of breeding ducks with an H6N6 avian influenza virus caused significant reproductive tract damage and decreased egg production. 42385378
2026-10 Experimental Infection Host Range Experiment In vivo challenge showed the H6N6 avian influenza virus infected mice, SPF chickens, and young Muscovy ducks, causing mild lesions. 42385378
2026-10 Genomic Evolution Recombination or Reassortment The isolated H6N6 avian influenza virus is a triple-reassortant derived from three distinct genetic clades. 42385378
2026-10 Zoonotic Surveillance Virus Isolation A novel H6N6 avian influenza virus was successfully isolated from affected breeding duck farms. 42385378
2026-10 Genomic Evolution Phylogenetic Evolution Phylogenetic analysis found multiple co-circulating H1 and H3 clades in swine and showed three H1 clades persisted exclusively in Vietnam for up to 12 years. 42811277
2026-10 Genomic Evolution Recombination or Reassortment The detected H5N1 virus in São Paulo was a reassortant derived from locally circulating LPAI viruses and highly pathogenic North American lineages. 42811438
2026-10 Functional Mechanism Molecular Adaptation The H6N6 avian influenza virus isolate carries HA substitutions A138S and A222V, molecular changes implicated in adaptation. 42385378
2026-09-29 Functional Mechanism Molecular Adaptation The combined neuraminidase mutations N70S and Y155H in H9N2 increase resistance to oseltamivir and zanamivir compared to single mutants, while remaining sensitive to peramivir. 42810520
2026-09-29 Experimental Infection Pathogenicity Experiment H9N2 avian influenza viruses with combined N70S and Y155H neuraminidase mutations caused high pathogenicity in BALB/c mice without prior adaptation. 42810520
2026-09-29 Genomic Evolution Phylogenetic Evolution Phylogenetic analysis indicates that HA A227E and NA S369N substitutions were acquired in swine prior to the emergence of H1N1pdm09 in humans. 42776754
2026-09-29 Functional Mechanism Molecular Adaptation In H1N1pdm09-related swine viruses, HA A227E reduces receptor binding and NA S369N in the 2SBS reduces NA cleavage, jointly adjusting the HA–NA balance linked to host-range adaptation before the 2009 pandemic emergence. 42776754
2026-09-29 Functional Mechanism Molecular Adaptation NAI resistance-associated neuraminidase positions in H9N2 viruses from China (1998–2024) include N70S, E119A/D/G/V, Q133K, Q136A, D151E, Y155H, I222V, R224K, E276D, R292K, N294S, and R371K. 42810520
2026-09-29 Experimental Infection Pathogenicity Experiment Neuraminidase inhibitors showed limited in vivo protective effect against H9N2 virus with combined N70S/Y155H mutations, potentially due to inability to ameliorate excessive inflammatory responses. 42810520
2026-09-28 Experimental Infection Host Range Experiment Full-length BC24 H5N1 hemagglutinin expressed in human A549 cells mediates membrane fusion, though at lower levels than prior H5 HAs. 42806028
2026-09-22 Genomic Evolution Recombination or Reassortment Most H5N1 and H5N9 genotypes detected in Korea in 2025–2026 are reassortants between East Asian clade 2.3.4.4b H5N1 HPAIVs (since 2022) and low-pathogenicity avian influenza viruses from wild birds. 42772571
2026-09-22 Zoonotic Surveillance Viral Detection Clade 2.3.4.4b H5N1 HPAIV was detected in poultry and wild birds in Korea during the 2025–2026 winter season, with numerous outbreaks and cases reported. 42772571
2026-09-22 Experimental Infection Pathogenicity Experiment In young ducks, H5N1 caused rapid mortality while H5N9 produced limited clinical signs without mortality. 42772571
2026-09-22 Zoonotic Surveillance Viral Detection Clade 2.3.4.4b H5N9 HPAIV was detected in poultry and wild birds in Korea during the 2025–2026 winter season. 42772571
2026-09-22 Zoonotic Surveillance Viral Detection Clade 2.3.4.4b H5N6 HPAIV was detected in poultry and wild birds in Korea during the 2025–2026 winter season. 42772571
2026-09-22 Experimental Infection Experimental Transmission H5N9 transmitted to all contact ducks in a controlled contact-transmission experiment. 42772571
2026-09-22 Experimental Infection Experimental Transmission H5N1 transmitted to all contact ducks in a controlled contact-transmission experiment. 42772571
2026-09 Functional Mechanism Molecular Adaptation H5N1 clade 2.3.4.4b carries an HA multibasic cleavage site and avian-specific receptor-binding residues (Q224, G226), supporting high pathogenicity and strong avian receptor affinity. 42767772
2026-09 Genomic Evolution Recombination or Reassortment An A(H5N1) clade 2.3.4.4b virus in Bangladesh is a reassortant with NA, PB1, NP, MP, and NS derived from contemporary A(H5N1) of ducks in LBMs, while PB2 and PA originate from LPAI viruses. 42767772
2026-09 Genomic Evolution Phylogenetic Evolution The HA gene of the Bangladesh HPAI A(H5N1) clade 2.3.4.4b virus clusters with recent LBM-origin strains from Bangladesh, with an MRCA around July 2023. 42767772
2026-09 Zoonotic Surveillance Serological Evidence An exposed domestic cat (CAT 2) seroconverted with antibodies against influenza A NP and H5/N1 antigens after initial PCR negativity. 42679799
2026-09 Zoonotic Surveillance Viral Detection HPAIV H5N1 clade 2.3.4.4b was detected in a domestic cat in Italy during an avian influenza outbreak on the same farm. 42679799
2026-09 Zoonotic Surveillance Virus Isolation Avian influenza virus A(H5N1) clade 2.3.4.4b was isolated from commercial quail during an outbreak in Bangladesh. 42767772
2026-09 Transmission Evidence Outbreak Investigation An outbreak investigation identified H5N1 clade 2.3.4.4b infection in domestic cats associated with a concurrent backyard poultry HPAI outbreak in Italy, with one fatal feline case and one seroconversion in an exposed cat. 42679799
2026-09 Zoonotic Surveillance Viral Detection A reassortant A(H5N1) clade 2.3.4.4b virus was detected in commercial poultry in Bangladesh, indicating ongoing circulation. 42767772
2026-09 Genomic Evolution Phylogenetic Evolution The PB2 gene of the A(H5N1) clade 2.3.4.4b virus carries a rare I147T substitution while mammalian-adaptive markers E627K and D701N are absent. 42767772
2026-09 Functional Mechanism Molecular Adaptation The feline H5N1 clade 2.3.4.4b isolate harbored PB2-E627K, a polymerase mutation linked to mammalian adaptation and increased pathogenicity. 42679799
Evidence-grounded Research Brief · Past week 6

Synthesizing linked evidence and source literature...

Generating an evidence-grounded brief with GPT-5...
1 source articles 3 hosts 0 countries
Publication date Category / type Key finding PMID
2026-10-08 Zoonotic Surveillance Virus Isolation An H9N2 avian influenza virus was isolated from a chicken in Shandong Province, China, in March 2019. 42849636
2026-10-08 Zoonotic Surveillance Virus Isolation An H9N2 avian influenza virus was isolated from a pig in Shandong Province, China, in March 2019. 42849636
2026-10-08 Genomic Evolution Recombination or Reassortment Two H9N2 viruses shared an identical reassortant genome: HA/NA from Y280-like, PB2/M from G1-like, and PB1/PA/NP/NS from SH/F98-like lineages. 42849636
2026-10-08 Experimental Infection Pathogenicity Experiment Two H9N2 viruses caused interstitial pneumonia and replicated in lungs and nasal turbinates of mice without significant weight loss or death and without detectable dissemination to other organs. 42849636
2026-10-08 Functional Mechanism Molecular Adaptation Both H9N2 isolates carried amino acid substitutions previously linked to mammalian adaptation, receptor binding, viral replication, and antigenic variation. 42849636
2026-10-08 Genomic Evolution Phylogenetic Evolution Both H9N2 isolates were classified as genotype G57 and closely related to H9N2 viruses previously detected in environmental samples in Jiangsu Province. 42849636

Evidence-related Animal

Evidence-related animal composition

168 animal taxa

Geographic evidence

Evidence distribution by country

62 countries

Temporal evidence

Evidence dynamics by year

318 year-type groups

Publication output

Source articles by month

405 months