ETIDIOH - NEW

  Abstract The ongoing outbreak of highly pathogenic avian influenza virus (HPAIV) subtype H5N1 in the U.S. poses a significant public health threat . To date, 70 human cases have been confirmed in the United States , including two severe cases and one fatality . While suitable animal models are crucial for predicting the potential pandemic risk of newly emerging pathogens in humans, studies investigating contemporary HPAIV H5N1 transmission dynamics remain limited. Here, we investigate the pathogenicity and transmission efficiency of recent clade 2.3.4.4b H5N1 viruses isolated from a bovine, mountain lion, and a human case using Syrian hamsters . Intranasal inoculation results in productive virus replication in the respiratory tract and shedding for all three isolates . Transmission studies demonstrate limited efficiency via direct contact and airborne routes for all isolates. Although overall transmission is inefficient , the human H5N1 isolate demonstrates relatively greater con...

  Situation at a glance Multi-country recalls of infant formula and other products have been initiated after cereulide toxin , was detected in batches of multiple internationally distributed brands .  Investigations have identified arachidonic acid (ARA) oil , used as an ingredient in the implicated products, as the source of contamination .  However, the full root cause analysis and complete traceability of all affected batches remains under investigation.  Contaminated formulae , nutritional products, and oil mixes have been distributed to 99 countries and territories across six WHO Regions, with the first product recalls initiated on 10 December 2025.  Between 1 January and 25 February 2026, 144 suspected and confirmed cases were reported across ten countries in three WHO Regions, with investigations ongoing.  Based on the available information , WHO assesses the overall public health risk as moderate due to the vulnerability of the affected population (...

{Excerpt} Time Period: March 01, 2026 - March 07, 2026 -- H5 Detection :  8 site(s) ( 1.6% ) -- No Detection :  491 site(s) ( 98.4% ) -- No samples in last week :  77 site(s) (...) Source: US Centers for Disease Control and Prevention,  Link:  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

  In the framework of passive surveillance activities, a report was received regarding backyard poultry (not considered as poultry) with clinical symptoms consistent with avian influenza. An outbreak of high pathogenicity avian influenza has been confirmed in the Cajabamba district of the Cajamarca department . The birds showed clinical signs such as weakening, hoarseness, eye discharge, and diarrhoea. The Official Authority activated quarantine, control, and surveillance measures in the outbreak and around the outbreak with the aim of identifying possible cases and preventing the spread of the outbreak. A notification was received regarding sick birds in a backyard (turkeys, ducks, roosters, hens, geese, and chickens) showing signs of depression, diarrhoea, and hoarseness. Source: WOAH,  https://wahis.woah.org/#/home Link:  https://wahis.woah.org/#/in-review/7358 ____

  {Northern Ireland} Pheasant breeder flock, with a small mixed backyard flock with chicken, geese. Positive test for HPAI H5N1, clinical signs presented prior to testing. Source:  Link:  https://wahis.woah.org/#/in-review/7368 ____

  Abstract Accumulating studies have identified the pivotal role of long non-coding RNAs (lncRNAs) in participating in host–virus interactions during virus infections . However, the regulatory roles of lncRNAs in influenza A virus (IAV) infection are still not fully elucidated . In this study, using high-throughput sequencing, we comprehensively compared the expression profiles of lncRNAs and mRNAs in mouse lungs infected either with the nonpathogenic parental (SDL124) H7N9 virus or its moderately pathogenic mouse-adapted (S8) variant . A total of 7636 significantly differentially expressed (SDE) lncRNAs were obtained in the S8-infected group compared to the mock group. As for the SDL124 group, 1042 SDE lncRNAs were identified. Subsequently, the mRNAs co-expressed with SDE lncRNAs were subjected to functional annotation and pathway enrichment analysis . The results indicated that the target mRNAs regulated by the S8 virus were mainly enriched in various immunological processes and ...

  Abstract Since the West African Ebola virus (EBOV) epidemic in 2014-2016, recurrent outbreaks of the EBOV-Makona variant have been driven by recrudescence and human-to-human transmission emphasizing the need for effective vaccination strategies . A live-attenuated recombinant vesicular stomatitis virus (VSV)-based vaccine expressing the EBOV-Kikwit variant glycoprotein (VSV-Kik) received FDA approval in December 2019 and provides complete, rapid protection against EBOV-Makona as early as 7 days post-vaccination (DPV). During the 2018-2020 Ebola outbreak , the VSV-Kik vaccine, known as ERVEBO , was administered to lower-risk individuals at a 5-fold dose reduction of the standard 2 × 107 PFU to provide broader population protection. Identification of a protective lower dose providing rapid protection would ease supply burdens during future outbreaks and enhance vaccine coverage. We previously generated a VSV-based vaccine expressing the glycoprotein of the Makona variant (VSV-Mak) ...

  Abstract While influenza A virus undergoes rapid antigenic drift in humans, at least some subtypes, such as H3, have relatively stable antigenicity in natural waterfowl reservoirs, despite the presence of immune pressure . However, the underlying mechanisms remain poorly understood. This study identified and characterized 187 antibodies to H3 hemagglutinin from experimentally infected mallard ducks , 18 of which were further analyzed by cryo-EM . Compared with human H3 antibodies , duck H3 antibodies exhibited higher glycan-binding propensity , more balanced immunodominance hierarchy , and targeted distinct epitopes . Other unique features of duck H3 antibodies included a convergent CDR H3-independent heavy chain-only binding mode and an N-glycosylated CDR H3 as decoy receptor . By annotating duck immunoglobulin germline genes , we also demonstrated the importance of gene conversion in duck H3 antibodies. Overall, our findings provide insights into how millennia of coevolution ha...

  Abstract In the United States, annual influenza vaccination has been recommended for all persons aged ≥6 months , including during the 2025–26 season. Interim influenza vaccine effectiveness (VE) estimates were calculated for patients with acute respiratory illness–associated outpatient visits and hospitalizations from three U.S. respiratory virus VE networks during the 2025–26 influenza season, using a test-negative case-control design . Among children and adolescents aged <18 years, VE was 38%–41% against influenza outpatient visits and 41% against influenza-associated hospitalization . Among adults aged ≥18 years, VE was 22%–34% against influenza outpatient visits and 30% against influenza-associated hospitalization . Among children and adolescents , VE against influenza A ranged from 37% (against outpatient visits) to 42% (against hospitalization) across settings; among adults , VE against influenza A ranged from 30% (against hospitalization) to 34% (against outpatient vis...

  Abstract Background :  The H1N1 influenza A virus evades host immunity through continuous antigenic drift, posing a significant challenge to broad-spectrum neutralizing antibody therapies. This study aims to systematically evaluate the neutralizing capacity of the broad-spectrum antibody C12H5 against H1N1 strains from different eras and identify key immune escape mutation sites .  Methods :  Three representative H1N1 virus strains from 2009, 2018, and 2023 were selected. An antigen–antibody binding prediction model based on the ESM-2 large language model was constructed by integrating 48,762 GISAID sequence data and deep mutation scanning data from the Bloom laboratory. Candidate escape sites were screened using SHAP (SHapley Additive exPlanations) value analysis. Mutant viruses were constructed via reverse genetics, and their neutralizing capacity and replication fitness were validated through hemagglutination inhibition assays, microneutralization assays, and vi...

  Abstract Marburgviruses (MBVs) cause severe haemorrhagic fever with higher fatality rates than Ebola virus (EBOV). Here we show that the MBV glycoprotein (GP) mediates viral entry more efficiently than EBOV GP . Using cryo-EM , we determined structures of MBV GP in three states : (1) unbound; (2) bound to its endosomal receptor NPC1; and (3) complexed with a neutralizing nanobody . The glycan cap shields the receptor-binding site from NPC1 but only partially from the nanobody , enabling limited immune evasion . After glycan cap cleavage , NPC1 binds to MBV GP in a distinct orientation compared with EBOV GP, providing an additional anchor and enhancing receptor affinity . NPC1 engagement also induces substantial conformational changes in MBV GP, probably facilitating membrane fusion . Furthermore, MBV GP is susceptible to the neutralizing nanobody , which mimics NPC1 at the receptor-binding site. Together, our findings reveal MBV GP as a highly efficient entry mediator and suggest...

  Abstract Enteroviruses, which belong to the family Picornaviridae, cause hand, foot, and mouth disease (HFMD), respiratory symptoms, and severe neurological complications in children . Since vaccines cannot provide cross-protection against different serotypes of enteroviruses , the development of broad-spectrum anti-enteroviral drugs is imperative . The viral 3C protease (3Cpro), which is essential for polyprotein processing represents a validated target for therapeutic intervention . Importantly, enterovirus 3Cpro shares conserved structural and catalytic features with coronavirus main protease (Mpro, also known as 3C-like protease, 3CLpro), providing a rationale for cross-target inhibitor repurposing . Through targeted screening of peptidomimetic protease inhibitors, a clinical-stage SARS-CoV-2 Mpro inhibitor was identified as a potent inhibitor of enterovirus A71 (EV71) 3Cpro. Bofutrelvir displayed nanomolar antiviral activity in multiple cell lines and demonstrated broad-spec...

  ABSTRACT Ferrets are widely used to model airborne transmission of influenza viruses in humans . Airborne transmission is evaluated by infecting donor ferrets with a high virus dose and monitoring transmission to contact animals sharing the same airspace . Humans can be infected with a broad range of influenza virus doses . Therefore, we evaluated the relationship between inoculation dose and transmission for two pandemic influenza viruses in ferrets . Donor ferrets were inoculated with 100 to 106 tissue culture infectious dose 50 (TCID50) of the 2009 pandemic H1N1 or 1968 pandemic H3N2 virus and were then paired with respiratory contacts . Using the proportion of donors that became infected across virus doses, we calculated the infectious dose 50 (ID50). Subsequently, by comparing the proportion of contacts that became infected, we calculated the transmissible dose 50% (TD50): the donor inoculation dose that resulted in transmission to 50% of contacts . For the 2009 pandemic H1N...

  More than ten days into the latest escalation of conflict in the Middle East, health systems across the Region are coming under strain as injuries and displacement rise , attacks on health care continue , and public health risks increase . National health authorities in Iran report more than 1300 deaths and 9000 injuries , and in Lebanon report at least 570 deaths and more than 1400 injuries . In Israel , authorities report 15 deaths and 2142 injuries . At the same time , the conflict is affecting the very services meant to save lives.  In Iran, WHO has verified 18 attacks on health care since 28 February, resulting in 8 deaths among health workers .  Over the same period in Lebanon, 25 attacks on health care have resulted in 16 deaths and 29 injuries. These attacks not only cost lives but deprive communities of care when they need it most.  Health workers , patients and health facilities must always be protected under international humanitarian law. Beyond the imm...

  Summary Background Lassa fever is one of the most important viral haemorrhagic fevers, yet post-discharge sequelae remain inadequately characterised . Previous studies have been limited by small sample sizes and unsystematic assessments. We aimed to describe post-discharge sequelae in Lassa fever survivors and explore the effect of disease severity on sequelae patterns. Methods LASCOPE was a prospective study of patients with PCR-confirmed Lassa fever hospitalised at Federal Medical Centre Owo, Owo, Nigeria , between April 23, 2018, and Feb 17, 2023. All patients who provided informed consent were included, with no age restriction. Severe disease was defined as the presence of at least one of the following during the acute phase: National Early Warning Score version 2 score of 7 or higher, Kidney Disease Improving Global Outcomes stage 2 or higher, or Lassa virus PCR Ct value of less than 25. At hospital discharge , follow-up of survivors was planned for day 60 after admission, o...

  Abstract We investigated the evolutionary history of the newly emergent neuraminidase (am4N1) associated with the D1.1 and D1.2 genotypes of highly pathogenic avian influenza A(H5N1) viruses in North America . Phylogenetic inference places am4N1 in a sister clade to Eurasian avian, swine, and human A(H1N1)pdm09 viruses and distinct from 1918, pre-2009 human seasonal, and classical swine A(H1N1) lineages . Am4N1 descends from diverse avian N1 genes endemic to the Americas. Phylodynamic analysis indicates a monophyletic am4N1 lineage with numerous introductions of viruses carrying the am4N1 gene likely originating from western Canada into the United States during emergence of the D1.1 and D1.2 genotypes. The lineage has diversified and accumulated deletions in the stalk domain . Despite amino acid divergence, structural modeling shows conserved neuraminidase architecture in the globular head . Given its distinct ancestry and amino acid sequence, further studies are needed to assess...

{Valparaíso} The birds shared a pond with wild birds. All birds were culled and buried on the property under strict biosecurity protocols. Cleaning and disinfection measures are being carried out. Source:  Link:  https://wahis.woah.org/#/in-review/7357 ____

  {Excerpts} On March 10, 2026, at 12:03 AM Italian time, a magnitude 5.9 earthquake occurred off the coast of Campania .  The seismic event occurred at an  extremely deep depth , approximately  414 km , well below the common seismogenic depths of Italian earthquakes, which predominantly occur in the upper crust. This deep event, quite rare for this geographical area , can be traced back to a geological process typical of the southern Tyrrhenian Sea  due to the presence in the Earth's mantle of a " slab " of oceanic lithosphere that has been sinking for several million years beneath the Tyrrhenian Sea. This phenomenon is accompanied by  frequent seismicity along the Calabrian and Sicilian coasts – less frequent off the Campanian coast – , with earthquakes that in the last 40 years have reached  magnitude ML 5.8 on 28 October 2016 ,  at a depth  of  481 km ,  and magnitude Mw 5.8 on 29 October 2006,  at a depth  of  2...

  Abstract Highly pathogenic influenza A viruses of the H5 subtype continue to diversify worldwide through mutation and genetic reassortment , generating novel variants with unpredictable consequences under the One Health approach . Between 2024 and 2025 , five outbreaks of avian influenza A viruses were detected in backyard poultry across Michoacán, Estado de México , and Ciudad de México . We conducted molecular and genetic characterization of five highly pathogenic H5N2 viruses isolated from these events. All cases tested positive for influenza A virus and the H5 hemagglutinin , exhibiting high pathogenicity with intravenous pathogenicity index values ranging from 2.88 to 3.0. Whole-genome sequencing revealed novel reassortants containing hemagglutinin from Eurasian H5N1 clade 2.3.4.4b and neuraminidase from the endemic Mexican H5N2 lineage . The viral genome of the isolate from Michoacán contained six segments derived from Eurasian H5N1 viruses introduced into North America in ...

  Summary Background The expanding mpox outbreak in Africa and travel-associated cases in other continents have increased efforts to vaccinate populations at high risk. This study aimed to assess serological immune responses 5 years after individuals received a primary vaccination (two-dose series) with the smallpox and mpox vaccine modified vaccinia Ankara-Bavarian Nordic (MVA-BN), as well as to evaluate the safety and immunogenicity of a third dose (booster). To date, there are no data for immunological memory or third-dose-induced immunity for MVA-BN at these long-term timescales. Methods In this open-label, prospective cohort extension, we re-enrolled health-care workers from a 2017 vaccination study in Bokungu Health Zone, DR Congo, to receive a third dose of MVA-BN. All previous participants were offered the opportunity to re-enrol. Participants were grouped according to whether they had received a childhood smallpox vaccination with a replication-competent vaccine strain (hi...