ETIDIOH - NEW

  A Dead swan found on lake shore in Federacija Bosna i Hercegovina. Source:  Link:  https://wahis.woah.org/#/in-review/7244 ____

  A breeding chickens farm in Śląskie Region. Source:  Link:  https://wahis.woah.org/#/in-review/7243 ____

  Di Jiyang Chen - Opera propria, CC BY-SA 3.0,  https://commons.wikimedia.org/w/index.php?curid=15507046 ___ This event was created to allow the recreation of outbreak ob_164520, previously reported as H5N1 subtype. Subadult unspecified seagull. In the Portuguese Exclusive Economic Zone.  Source:  Link:  https://wahis.woah.org/#/in-review/7234 ____

  Abstract Limited information is available on the impact of non-pharmaceutical interventions (NPIs) and immune debt on influenza during COVID-19 . This retrospective population-based research examined the effect of the COVID-19 pandemic on the prevalence of influenza-like illness (ILI) cases and influenza positive cases in Sichuan Province . Interrupted time series analysis (ITS) was conducted using data gathered from surveillance hospitals throughout 21 cities , including information on patients diagnosed with ILI and positive nucleic acid testing. Subsequent to the implementation of NPIs, there was a notable temporary reduction in both the incidence of ILI cases and confirmed influenza cases, decreasing by 94.7% and 98.0%, respectively (P<0.001). The weekly trend in influenza-positive cases was notable (+4.1%/week, P=0.001). Following the execution of the second-phase intervention, the fluctuations in the transient changes of ILI patients and influenza-positive cases varied ;...

  Abstract We examined whether the recent emergence of influenza A(H3N2) subclade K, associated with an unusually early influenza season in the Northern hemisphere, was accompanied by a reduction in human population immunity . Using virus neutralisation assays on pre-epidemic human sera collected in May 2025, we found evidence of moderate antigenic drift . Further, vaccines used in the 2024/2025 season induced cross-neutralising immunity . These findings provide timely insight for interpreting recent influenza epidemiology and informing vaccine strain selection. Competing Interest Statement The following authors declare no conflict of interests: KD, RI, LM, SR, HC, GGA, MSA, VS, ZW, SKW, JZ, BJW, DLR, JH, OML, JG, CJRI. PRM receives funding for research work for MSD. EH has received an honorarium for advisory board work for Seqirus. ET has received funding from Novavax and Astra Zeneca. Funding Statement This work was funded by the Medical Research Council (MRC) to the MRC-Universi...

  Abstract Oz virus (OZV), a member of the genus Thogotovirus in the family Orthomyxoviridae, is an emerging tick-borne virus reported in Japan . A fatal human case and seroepidemiological evidence of widespread exposure among wild animals and humans suggest its potential public health significance . However, no animal models suitable for pathogenic studies or evaluation of countermeasures are available for OZV. Here, we have established a lethal mouse model of OZV infection using cell-adapted virus and mice lacking type I interferon signaling (B6 Ifnar1 KO mice). OZV infection resulted in 100% mortality and was characterized by robust viral replication in the liver and spleen, severe hepatitis, and acute liver injury . Using this model, we also demonstrated that oral administration of T-705 , an antiviral drug widely used against RNA viruses, as well as immunization with an inactivated whole virus particle vaccine, protected B6 Ifnar1 KO mice from lethal OZV infection by mitigatin...

  A foie gras goose holding in Jász-Nagykun-Szolnok Region. Source:  Link:  https://wahis.woah.org/#/in-review/7237 ____

  Abstract Background :  Chikungunya virus (CHIKV) has historically been regarded as a low-fatality infection ; however, growing evidence from diverse study designs demonstrated a substantial mortality burden during large-scale epidemics. In 2025, Réunion Island experienced a major CHIKV outbreak , raising renewed concerns about its fatal impact.  Methods :  We conducted an ecological time-series analysis of all-cause mortality during the 2025 chikungunya epidemic. Expected deaths were estimated using two complementary approaches: (i) a baseline based on age-specific mean mortality rates from the same calendar months in the post-pandemic period and (ii) long-term Poisson regression models using a log-link function and population offset, excluding the COVID-19 pandemic period. Excess mortality was calculated as the difference between observed and expected deaths during periods when observed mortality significantly exceeded the upper bound of the 95% confidence interva...

  Abstract Influenza A viruses continually pose pandemic threats, underscoring the need for timely development of Candidate Vaccine Viruses (CVVs) that meet regulatory expectations for vaccine manufacturing. This protocol describes the procedures used at CDC to generate recombinant CVVs through reverse genetics in accordance with World Health Organization guidelines and CDC’s internal Quality System Requirements (QSR)1,2,3. The QSR incorporates relevant principles from the FDA’s Good Manufacturing Practice (GMP) and Good Laboratory Practice (GLP) regulations, providing a structured framework that ensures documentation integrity, material traceability, and quality oversight during all stages of CVV development. The protocol provides detailed steps for plasmid preparation , virus rescue in Vero cells , and amplification in embryonated chicken eggs , and outlines characterization assays used to confirm the suitability and safety attributes of each CVV. This standardized, quality-drive...

  Abstract Influenza A virus (IAV) is a zoonotic pathogen with a broad host range, posing an ongoing threat to global public health . As the core subunit of the IAV polymerase , polymerase basic protein 1 (PB1) is essential for viral replication and transcription , and its mutations are key drivers of viral evolution . This review evaluates the impact of PB1 mutations on IAV evolution, with a focus on polymerase activity, host adaptation, transmissibility, and virulence. Additionally, it discusses the implications of these mutations for vaccine development. The review aims to provide insights that can inform influenza surveillance, identify novel antiviral targets, and guide vaccine design. Source:  Link:  https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2026.1768665/full ____

  Abstract In the present study, we assessed the pathogenicity of H5N8 avian influenza viruses belongs to the clade 2.3.4.4b in chicken. Birds of three different dose groups, 10 2 , 10 4 , and 10 6 EID 50 were used in the study. No mortality was observed in 10 2 EID0 group. Percent cumulative mortality of 10 4 and 10 6 EID 50 group was 66.67 and 100 %, respectively. Varying duration of MDT of 3.2 and 2 days was observed in 10 4 and 10 6 EID 50 group, respectively. The CID 50 of virus was found to be 10 4.5 EID 50 . High no. of viral RNA copies were found both in oropharyngeal and cloacal swabs and in various organs of birds infected in 10 4 and 10 6 EID 50 group. Significant gross and histological changes and presence of viral antigen in various organs were observed in 10 4 and 10 6 EID 50 group. So, the study concludes that Indian HPAI, H5N8 isolates are highly pathogenic in nature to chicken by affecting most organs systemically. CID 50 of this H5N8 virus indicates poor adaption ...

  ABSTRACT Vaccinia virus (VACV) confers cross-protective immunity against monkeypox virus (MPXV), the causative agent of mpox, and has therefore been extensively exploited as a preventive vaccine . VACV Tiantan strain (VTT) is a second-generation smallpox vaccine used in China in the last century, and there are consistent efforts to minimize its virulence and ensure its best safety for potential clinical applications. In this study, an attenuated VACV rVTT△C12K2△A45 was constructed by deletion of gene segments related to virulence genes , host range genes, immune regulatory genes, and other functional genes from the VTT genome by genetic engineering. Attenuation characteristics of rVTT△C12K2△A45 were confirmed by smaller plaque size, lower replication capacity in various mammalian cell lines along with tests for neurotoxicity in mice , and lesion formation on rabbit skin . Immunization in BALB/c mice with rVTT△C12K2△A45 induced both anti-MPXV and anti-VACV neutralizing antibodies ...

  • New human cases {2}:  -- From 20 December 2025 to 22 January 2026 , based on reporting date, the detection of A(H9N2) in three humans was reported officially.  • Circulation of influenza viruses with zoonotic potential in animals :  -- High pathogenicity avian influenza (HPAI) events in poultry and non-poultry animal species continue to be reported to the World Organisation for Animal Health (WOAH).{3}  -- The Food and Agriculture Organization of the United Nations (FAO) also provides a global update on avian influenza viruses with pandemic potential.{4}  -- Additionally, low pathogenicity avian influenza viruses as well as swine influenza viruses continue to circulate in animal populations.  • Risk assessment {5}:  -- Sustained human to human transmission has not been reported associated with the above-mentioned human infection events.  -- Based on information available at the time of this risk assessment update, the overall public hea...

  A wild Greylag Goose in Lubelskie Region. Source:  Link:  https://wahis.woah.org/#/in-review/7227 ____

  Poultry farms in Békés Region. Source:  Link:  https://wahis.woah.org/#/in-review/7228 ____

  Abstract Comparably few lineages of influenza A virus (IAV) have evolved long-term sustained transmission in mammals . The reasons remain largely unknown , and the possibility of avian IAVs evolving sustained mammalian transmission is an ongoing concern . Here we measured the GC content and frequency of GC dinucleotides in 115,520 whole genomes of IAVs using bioinformatic analyses . We found that persistent mammalian lineages showed declining trends in GC-related content and could be reliably separated from IAVs circulating only in birds and those sporadically infecting mammals. Similarly, the earliest viruses of persistent mammalian lineages showed reduced GC-related content , suggesting that this trait might in part contribute to their eventual persistence . Recent highly pathogenic 2.3.4.4b H5 viruses that spread in mink, foxes and humans were also characterized by reduced GC-related content . While not sufficient, reduced GC-related content may be a necessary condition for su...

  Abstract The Caucasus region, including Georgia, is an important intersection for migratory waterbirds , offering potential for avian influenza virus (AIV) transmission between populations from different geographic areas. In 2022 and 2023, wild ducks were sampled during autumn migration events in Georgia to study the genetic relationships and molecular characteristics of influenza strains. Sequencing and phylogenetic analysis were used to compare the sampled strains to reference sequences from Africa, Asia, and Europe , allowing assessment of genetic relationships and virus transmission between migratory birds. Protein language modeling identified potential co-infections. Of 225 duck samples, 128 tested positive for the influenza M gene . 55 influenza-positive samples underwent whole-genome sequencing, revealing significant diversity. Analysis of the hemagglutinin (HA) segment showed notable differences among subtypes. Most samples were H6N1 and H6N6 , but co-infections with comb...

  Highlights •  Viremia in children with La Crosse Virus infection is transient; viral RNA was detected in only 3.2% of sera •  Detection of La Crosse Virus RNA in respiratory samples is slightly higher at 21.7% and may reflect the temporal distribution of the virus after infection •  NAAT has limited utility in routine diagnosis of La Crosse Virus encephalitis in children but may still be useful in cases with delayed seroconversion Abstract Background La Crosse virus (LACV), a member of family Peribunyaviridae, genus Orthobunyavirus , is the leading cause of neuroinvasive arboviral infection in children in the United States . Diagnosis relies on detecting specific antibodies (IgG or IgM), a 4-fold titer rise or seroconversion, in patients with compatible presentations. NAAT used for LACV detection has largely been limited to mosquito, animal models or postmortem brain tissue. There is a lack of data on the performance of NAATs in clinical specimens from living patie...

  Abstract Neuraminidase inhibitors (NAIs) and cap-dependent endonuclease inhibitors (CENIs) represent two classes of antiviral drugs recommended for early treatment of patients with seasonal influenza A virus (IAV) infections. However, only limited human data , particularly on combination antiviral treatment , are available to inform optimal dosing regimens against novel IAVs, including highly pathogenic avian influenza A(H5N1) virus , associated with severe disease . Clade 2.3.4.4b A( H5N1 ) viruses have caused outbreaks in avian and mammalian species worldwide , highlighting the need to assess antiviral drug efficacy against these strains. We challenged ferrets with a D1.1 genotype A(H5N1) virus and treated infected animals with the NAI oseltamivir phosphate (OST) and the CENI baloxavir acid (BXA), alone or in combination , with treatment onset commencing pre- or post-symptom onset (24- or 48-hours post-inoculation (p.i.), respectively). When administered pre- or post-illness on...