ETIDIOH - NEW

  Abstract Clade 2.2 H5N1 influenza viruses have caused an unusually high number of human infections , providing a unique opportunity to investigate early molecular steps associated with host adaptation . Although most work has focused on hemagglutinin (HA), the contribution of neuraminidase (NA) to these early adaptive events has remained unclear. By analyzing publicly available sequences from clade 2.2-infected patients , we identified 20 NA mutations and compared their phenotypes to 20 mutations acquired during diversification in primary human airway cells under drug-free conditions. Most patient-derived NA mutations resulted in modest reductions in sialidase activity , keeping activity within a functional range that supported improved replication in α2,6 sialylglycan (α2,6 Sia)-dominant environments , whereas excessive reduction impaired fitness . Notably, the phenotypes of culture-selected and patient-derived mutations were highly concordant , suggesting that these NA changes ...

  {Excerpt} Time Period: January 11, 2026 - January 17, 2026 -- H5 Detection :  6 site(s) ( 1.1% ) -- No Detection :  519 site(s) ( 98.9% ) -- No samples in last week:  78 site(s) (...) Source:  Link:  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

  Abstract The continuous evolution and global spread of highly pathogenic avian influenza (HPAI) H5N1 viruses , particularly clade 2.3.4.4b, pose major challenges for pandemic preparedness . This study evaluates a low-dose inactivated split-virus vaccine derived from H5N1 clade 2.3.4.4b, formulated with an Alum/CpG adjuvant , in a preclinical female mouse model . The vaccine induces strong humoral and cellular immunity , generating high titers of cross-reactive antibodies against diverse H5 hemagglutinin (HA) and across different N1 neuraminidase (NA) glycoproteins. The Alum/CpG adjuvant supports substantial antigen dose sparing and promotes a balanced Th1/Th2 profile. Functional assays show potent virus neutralization , neuraminidase inhibition , and antibody-dependent cellular cytotoxicity , alongside robust antigen-specific CD4+ and CD8+ T cell responses, efficient control of lung viral replication, and reduced lung inflammation . Vaccinated mice are fully protected from lethal...

  Highlights • All clades of monkeypox virus (MPXV) continue to circulate.  - Unless mpox outbreaks are rapidly contained and human-to-human transmission is interrupted, there is a risk of sustained community transmission .   • At the time of reporting, data from the WHO European Region for December 2025 had not yet been submitted; therefore, the information presented below does not include the European Region .  • In December 2025 , 31 countries across five WHO regions (European Region excluded) reported a total of 1040 new confirmed mpox cases , including six deaths (case fatality ratio [CFR] 0.6%).  - Of these cases, 78% were reported in the African Region .  - Four regions observed a decline in confirmed cases in December, compared to November 2025, while the Eastern Mediterranean Region reported more cases than the previous month.      • Fifteen countries in Africa reported active transmission of mpox in the last six weeks (7 Decemb...

  {England, Suffolk}  10,532 bird duck breeder flock. Samples taken were positive for HPAI H5N1. Birds presented clinical signs prior to testing. Source:  Link:  https://wahis.woah.org/#/in-review/7217 ____

  Eight wild mute swans in Vaslui Region. Source:  Link:  https://wahis.woah.org/#/in-review/7218 ____

  A wild whooper swan in Pomoravski Region. Source:  Link:  https://wahis.woah.org/#/in-review/7220 ____

  Abstract In November 2024, an adolescent female in British Columbia was hospitalized presenting with severe symptoms including respiratory failure due to infection with a novel H5N1 subtype influenza strain (BC24). Using cryogenic electron microscopy (cryo-EM), we show here that the N169 α2,3-linked auto-glycan that is found in the sialic acid binding site of previously studied H5 hemagglutinin (HA) proteins is absent in purified BC24 HA protein , suggesting greatly reduced affinity for α2,3-linked sialosides . Glycan microarray analysis shows that the BC24 HA protein displays reduced or no binding not just to most α2,3-linked sialosides, but also to α2,6-linked sialosides . Full-length BC24 HA expressed in A549 lung alveolar carcinoma cells drives membrane fusion, albeit at significantly lower levels than previous H5 HA proteins, and post-infection sera from the patient display strong binding to BC24 HA and HA proteins from other influenza subtypes. The high virulence of the BC2...

  Abstract The risk of highly pathogenic avian influenza infection to humans is challenging to estimate because many human avian influenza virus (AIV) infections are undetected as they may be asymptomatic , symptomatic but not tested , and as contact tracing is difficult because human-to-human spread is rare. We derive equations that consider the evolutionary mechanisms that give rise to pandemics and are parameterized to be consistent with records of past pandemics. We estimate that thousands of human AIV infections occur worldwide in an average year and estimate the infection fatality ratio as 32 deaths per 10,000 infections (95% confidence interval: [9.6, 75]). We estimate that preventing 20% of animal-to-human influenza spillovers annually would delay pandemic emergence by an average of 9.4 years . There is a high level of uncertainty in our estimates due to the few records of past pandemics, but even so this infection fatality ratio is comparable to SARS-CoV-2 during the recen...

  ABSTRACT The outbreak of highly pathogenic avian H5 influenza (HPAI) clade 2.3.4.4b in cattle has spread across the United States . Mice with pre-existing immunity to H1N1 virus or with a live-attenuated influenza vaccine showed protection against a lethal bovine-derived HPAI H5N1 viral challenge . Notably, ferrets with mixed immunity also demonstrated protection against a feline-derived H5N1 virus, independent of cross-reactive neutralization titers , but antibodies to whole virus were observed. To investigate protective factors, we conducted T cell epitope mapping using published H1N1 viral sequences and found high conservation of key T cell epitopes in the bovine HPAI H5N1 strain . Depletion of T cells in mice prior to and during primary H1N1 infection impacted cross-protective antibodies to H5N1 virus, with CD4 depletion increasing mortality and CD8 depletion mildly impacting morbidity upon H5N1 viral challenge. This underscores the need to investigate memory T cell responses...

  Abstract Diseases caused by henipaviruses, exemplified by Hendra virus and Nipah virus, pose a serious risk to public health because of their epidemic potential and high case-fatality rates and the paucity of medical countermeasures to mitigate them. In December 2024, a group of 150 scientists from 16 countries convened in Geelong, Victoria, Australia, to mark the 30th anniversary of the discovery of Hendra virus . The Hendra@30 conference built upon its predecessor conference held in 2019 in Singapore, Nipah@20, by expanding its program across broader disciplines and integrating sessions on human sociology and disease ecology into the main scientific discussions. We describe key highlights from Hendra@30 and reflect on 4 key elements that have advanced henipavirus research and medical countermeasures research and development. We propose that integrating bat ecology into henipavirus research blueprints will enable development of ecologic countermeasures that prevent spillover and...

  A wild mute swan in Etelä-Suomen aluehallintovirasto Region. Source:  Link:  https://wahis.woah.org/#/in-review/7213 ____

A wild mute swan.  Last outbreak in wild birds in Podkarpackie region was confirmed in February 2025. Source:  Link:  https://wahis.woah.org/#/in-review/7215 ____

  Abstract We evaluated 2 electrochemiluminescence serologic assays to detect avian influenza H5 antibodies . Both assays identified H5 antibodies from both serum and dried blood spots and had strong specificity and minimal cross-reactivity in human and avian samples. Such assays can support populationwide serologic surveys aimed at assessing population-level immunity. Source:  Link:  https://wwwnc.cdc.gov/eid/article/32/1/25-1117_article ____

  Abstract In 2009 and again in 2019, public health warnings were confirmed by the emergence, rapid widespread transmission, and lethality of novel influenza and coronaviruses . The world continues to suffer disease from these respiratory viruses. Two newly recognized emergent respiratory viruses, influenza D and canine coronavirus HuPn-2018 , have been shown to have considerable potential for causing future human epidemics , but diagnostics and surveillance for the viruses are lacking. We reviewed data regarding influenza D virus and coronavirus canine coronavirus HuPn-2018 . Those data strongly indicate that these viruses are major newly recognized threats . However, little is being done to respond to or prevent disease associated with these viruses, warranting the question of whether we will learn from previous pandemics. Source:  Link:  https://wwwnc.cdc.gov/eid/article/32/1/25-1764_article ____

Abstract Highly pathogenic avian influenza A (H5N1) (H5N1 hereafter) is an emerging pathogen in mammals . The recent recognition of H5N1 in dairy cattle increases opportunities for human exposure and infection and may accelerate a trajectory toward sustained human-to-human transmission . Furthermore, the presence of virus at high concentration in unpasteurized milk raises new risks for humans , especially infants and children . Milk has been identified as a vehicle for viral transmission in and between mammalian species, including humans. Sialic acids (SAs) found on cell surfaces are important mediators of species susceptibility to specific influenza strains and play an important role in viral tropism . New data demonstrate that SA receptors with α2,3 linkages capable of binding avian influenza strains are present in human mammary tissue . The presence of SA receptors that can bind avian influenza and a comparative analysis of viral transmission risk of raw and pasteurized milk in seve...

  Highlights •  Global mobility, climate pressures, and ecological change drive emerging infections. •  Highly pathogenic influenza strains, including H5N1, pose ongoing spillover risks and pandemic potential. •  SARS, MERS, and COVID-19 illustrate the pandemic potential of novel coronaviruses. •  Nipah, Ebola, Pteropine orthoreovirus and Zika remain high-impact threats for global health security. •  Mass gatherings can amplify transmission risks of emerging high-consequence viruses. •  Strengthened surveillance, diagnostics, and One Health strategies are essential for pandemic preparedness. Abstract Emerging infectious diseases have risen significantly in the twenty-first century as ecological disruption, climate change, expanding human–animal interfaces , and global mobility intensify opportunities for pathogen transmission . This review synthesizes historical and contemporary evidence across viral, bacterial, fungal, and parasitic threats to charact...

  Abstract Sialic acids (SAs) are abundantly expressed on vertebrate cell surfaces and are widely recognized as key viral attachment factors , particularly for influenza viruses . However, their role remains understudied in other orthomyxoviruses, such as thogoto and quaranja viruses , which are tick-borne viruses sporadically infecting humans. Enzymatic removal of SAs increased the infectivity of Thogoto and Dhori viruses , as well as pseudotypes carrying the glycoproteins of Oz, Sinu, and Wellfleet Bay viruses . A similar effect on pseudotype infectivity was observed following the binding of specific lectins to SAs. These findings indicate that, in contrast to influenza viruses, SAs act as a barrier to the entry of these orthomyxoviruses . Experimental evolution of the Sinu and Wellfleet Bay virus glycoproteins revealed point mutations that partially overcame this barrier . Given the abundance of sialic acids in mucosal tissues, we speculate that SAs may contribute to the inabili...

  Summary Highly pathogenic avian influenza A(H5N1) viruses have been circulating among wild birds and are enzootic in poultry in some areas of the world with spillover to a wide range of terrestrial and marine mammals. Since 1997, sporadic animal to human , primarily poultry to human, transmission of highly pathogenic avian influenza A(H5N1) viruses has been reported in 25 countries . More recently there have been locally acquired infections in the Americas due to the 2.3.4.4b clade of the virus. Most of the recently detected human infections in the USA have been relatively mild but there have been cases of critical illness reported in several countries. In this Grand Round we present the first locally acquired highly pathogenic avian influenza A(H5N1) virus infection in Canada , which was in a 13-year-old female, who developed severe disease requiring prolonged critical care . She was infected with a clade 2.3.4.4b, genotype D1.1 virus and developed evidence of cytokine storm and...

  Abstract Objective :  This systematic review aimed to assess the clinical effectiveness and safety profile of baloxavir marboxil for managing influenza in pediatric populations . Methods :  This review has been registered on the INPLASY platform (INPLASY2025110063). Designed in accordance with the PRISMA 2020 guidelines, we searched four major biomedical databases (PubMed, Embase, Web of Science, Cochrane Library) covering publications from January 1, 2015, to January 30, 2025 . Eligibility criteria encompassed both randomized controlled trials and observational cohort studies evaluating this antiviral agent in children with laboratory-confirmed influenza. Methodological rigor was appraised using the Cochrane Collaboration's risk of bias instrument for randomized controlled trials (RCTs) and the Newcastle-Ottawa Quality Assessment Scale for cohort studies. Statistical synthesis was conducted using RevMan 5.3 software (Version 5.3.5) with metafor package implementation. ...