ETIDIOH - NEW

Abstract Highly pathogenic avian influenza (HPAI) virus subtype H5N1 has never been detected in New Zealand . The potential impact of this virus on New Zealand's wild birds would be catastrophic. To expand our knowledge of avian influenza viruses across New Zealand, we sampled wild aquatic birds from New Zealand, its outer islands and its subantarctic territories. Metatranscriptomic analysis of 700 individuals spanning 33 species revealed no detection of H5N1 during the annual 2023-2024 migration. A single detection of H1N9 in red knots (Calidris canutus) was noted. This study provides a baseline for expanding avian influenza virus monitoring in New Zealand. Source: US National Library of Medicine,  https://pubmed.ncbi.nlm.nih.gov/40148670/ ____

February 2025  The development of influenza candidate vaccine viruses (CVVs),  coordinated by WHO, remains an essential component of the overall global  strategy for influenza pandemic preparedness . Selection and development of  CVVs are the first steps towards timely vaccine production and do not imply a  recommendation for initiating manufacture. National authorities may consider the  use of 1 or more of these CVVs for pilot lot vaccine production, clinical trials and  other pandemic preparedness purposes based on their assessment of public health  risk and need. Zoonotic influenza viruses continue to be identified  and evolve both antigenically and genetically, leading to the need for additional  CVVs for pandemic preparedness purposes. Changes in the antigenic and genetic  characteristics of these viruses relative to existing CVVs and their potential risks  to public health justify the need to develop new CVVs. This docume...

{Excerpt} Time Period: March 16 - March 22, 2025 -- H5 Detection :  5 sites ( 1.2% ) -- No Detection :  401 sites ( 98.8% ) -- No samples in last week :  211 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/bird-flu/h5-monitoring/index.html ____

{England} Small ~53 chicken backyard flock, commercial premises (egg sold). Increased mortality and other clinical signs for HPAI were reported. Samples taken tested positive for HPAI H5N1. Source: WOAH,  https://wahis.woah.org/#/in-review/6373 ____

Context and significance Wang et al. provided valuable insights into the epidemiological patterns of avian influenza virus (AIV) spillover and the role of H9N2 in the process. Their analysis highlighted the significant contribution of the internal genes (INGEs) from 12 key strains of H9N2 in facilitating human adaptability by reducing the species barrier between poultry and humans , essentially acting as internal genetic donors for AIV spillover . Due to its low pathogenicity, H9N2 has been neglected in poultry vaccination programs , leading to a lack of vaccines specifically targeting the INGEs of these 12 key strains. Their findings suggest that reducing the prevalence of H9N2 is fundamental to mitigating AIV spillover risks. Highlights •  H9N2 exerts a promoting effect on the spillover of avian influenza viruses (AIVs) •  Expansion of AIV spatial and host ranges reveals an emerging risk of its spillover •  Prevalence of AIVs in human -contacted hosts reveals a re-emerg...

Backyard and farm-reared poultry in Andhra Pradesh State. Source: WOAH,  https://wahis.woah.org/#/in-review/6344 ____

Situation at a glance On 11 March 2025, the World Health Organization (WHO) received a report from the International Health Regulation (2005) (IHR) National Focal Point (NFP) of the United States of America (United States) on the ongoing measles outbreak in the country , notified under IHR because it is an unusual event with potential significant public health impact , with the number of cases and deaths in 2025 exceeding the numbers in previous years. Additionally, cases linked to the outbreak in the State of Texas, United States, have been reported in Mexico . Measles is a highly contagious, airborne viral disease that can lead to severe complications and death. From 1 January to 20 March 2025, 17 States have reported a total of 378 cases of measles , including two deaths - the first deaths related to measles in the United States in a decade. The majority of cases are in children who are unvaccinated or have unknown vaccination status, and the overall hospitalization rate is 17%. In ...

ABSTRACT The H5N1 avian panzootic has resulted in cross-species transmission to birds and mammals, causing outbreaks in wildlife, poultry, and US dairy cattle with a range of host-dependent pathogenic outcomes . Although no human-to-human transmission has been observed, the rising number of zoonotic human cases creates opportunities for adaptive mutation or reassortment . This Gem explores the history, evolution, virology, and epidemiology of clade 2.3.4.4b H5N1 relative to its pandemic potential. Pandemic risk reduction measures are urgently required. Source: Journal of Virology,  https://journals.asm.org/doi/full/10.1128/jvi.02209-24?af=R ____

Abstract Highly pathogenic avian influenza A(H5N1) virus has caused a multistate outbreak among US dairy cattle , spreading across 16 states and infecting hundreds of herds since its onset. We rapidly developed and optimized PCR-based detection assays and sequencing protocols to support H5N1 molecular surveillance . Using 214 retail milk samples from 20 states for methods development, we found that H5N1 virus concentrations by digital PCR strongly correlated with quantitative PCR cycle threshold values ; digital PCR exhibited greater sensitivity. Metagenomic sequencing after hybrid selection was best for higher concentration samples, whereas amplicon sequencing performed best for lower concentrations. By establishing these methods, we were able to support the creation of a statewide surveillance program to perform monthly testing of bulk milk samples from all dairy cattle farms in Massachusetts , USA, which remain negative to date. The methods, workflow, and recommendations described p...

Abstract The coronavirus membrane protein (M) is the main organizer of coronavirus assembly. Here, we report on an M-targeting molecule , CIM-834, that blocks the assembly of SARS-CoV-2. CIM-834 was obtained through high-throughput phenotypic antiviral screening followed by medicinal-chemistry efforts and target elucidation. CIM-834 inhibits the replication of SARS-CoV-2 (including a broad panel of variants) and SARS-CoV. In SCID mice and Syrian hamsters intranasally infected with SARS-CoV-2, oral treatment reduced lung viral titres to nearly undetectable levels, even (as shown in mice) when treatment was delayed until 24 h before the end point. Treatment of infected hamsters prevented transmission to untreated sentinels. Transmission electron microscopy studies show that virion assembly is completely absent in cells treated with CIM-834. Single-particle cryo-electron microscopy reveals that CIM-834 binds and stabilizes the M protein in its short form, thereby preventing the conformati...

ABSTRACT Unexpected outbreaks caused by the H5N1 highly pathogenic avian influenza virus (HPAIV) in dairy cows in the United States (US) have raised significant veterinary and public health concerns . When and how the H5N1 HPAIV was introduced into dairy cows and the broader epidemiology of influenza A virus (IAV) infections in cattle in the US remain unclear. Herein, we performed a retrospective study to screen more than 1,700 cattle serum samples collected from different bovine breeds in the US from January 2023 to May 2024 using an enzyme-linked immunosorbent assay (ELISA) targeting the nucleoprotein (NP) to detect IAV infections, and the positive samples were further tested by hemagglutination inhibition (HI) assay . Results showed that 586 of 1,724 samples (33.99%) from 15 US states were seropositive by the NP ELISA assay , including 78 samples collected in 2024 and 508 samples collected in 2023 . Moreover, the HI assay revealed that 45 of these ELISA-positive samples were positiv...

A mink farm in Lombardy Region. The minks were controlled in the framework of a national surveillance plan. Source: WOAH,  https://wahis.woah.org/#/in-review/6367?reportId=173318&fromPage=event-dashboard-url ____

LETTER Transmission among mammals of bovine highly pathogenic avian influenza (HPAI) H5N1 viruses , which have caused outbreaks in US dairy cattle (1–3), has been demonstrated in ferrets by our group (4, 5) and the US Centers for Disease Control and Prevention (CDC) (6). These studies showed that these viruses can be transmitted among ferrets via respiratory droplets , albeit with lower efficiency than seasonal human influenza viruses. In contrast, bovine HPAI H5N1 viruses spread easily among ferrets through direct contact (3 of 3 [100%] ferrets) (6). Although ferrets are frequently used for influenza virus transmission (7–9) and vaccine efficacy (10, 11) studies, they demand considerable housing space and personnel and can be difficult to handle. Here, we investigated the transmissibility of the bovine HPAI H5N1 virus A/Texas/37/2024 (TX/37), which was 100% lethal in ferrets inoculated with as little as 10 plaque-forming units (PFUs) (5) by using a hamster model .  (...) Bovine HP...

Abstract In the past two decades, two pandemic respiratory viruses (H1N1 and SARS-CoV-2) have emerged via spillover from animal reservoirs . In an effort to avert future pandemics, surveillance studies aimed at identifying zoonotic viruses at high risk of spilling over into humans act to monitor the `viral chatter' at the animal-human interface . These studies are hampered, however, by the diversity of zoonotic viruses and the limited tools available to assess pandemic risk. Methods currently in use include the characterization of candidate viruses using in vitro laboratory assays and experimental transmission studies in animal models . However, transmission experiments yield relatively low-resolution outputs that are not immediately translatable to projections of viral dynamics at the level of a host population. To address this gap, we present an analytical framework to extend the use of measurements from experimental transmission studies to generate more quantitative risk assessm...

Abstract The ongoing panzootic of highly pathogenic avian influenza (HPAI) H5 clade 2.3.4.4b has caused widespread poultry mortality and raised concerns about zoonotic pandemics and wildlife conservation . France recently adopted a preventive vaccination strategy , vaccinating domestic ducks with inactivated and mRNA vaccines . This study evaluates the impact of this campaign on reducing HPAI H5 outbreaks. Using predictive modeling based on previous outbreak data, the expected number of outbreaks in 2023-24 without vaccination was significantly higher than the observed cases, indicating a 95.9% reduction attributable to vaccination . These findings suggest that vaccination effectively mitigated the HPAI H5 outbreak in France. Source: BioRxIV,  https://www.biorxiv.org/content/10.1101/2024.08.28.609837v3 ____

 A poultry farm in Khulna Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6351 ____

Abstract Ebola virus (EBOV) and Marburg virus (MARV) are zoonotic filoviruses that cause hemorrhagic fever in humans . Correlative data implicate bats as natural EBOV hosts , but neither a full-length genome nor an EBOV isolate has been found in any bats sampled. Here, we model filovirus infection in the Jamaican fruit bat (JFB), Artibeus jamaicensis, by inoculation with either EBOV or MARV through a combination of oral, intranasal, and subcutaneous routes . Infection with EBOV results in systemic virus replication and oral shedding of infectious virus. MARV replication is transient and does not shed. In vitro, JFB cells replicate EBOV more efficiently than MARV, and MARV infection induces innate antiviral responses that EBOV efficiently suppresses. Experiments using VSV pseudoparticles or replicating VSV expressing the EBOV or MARV glycoprotein demonstrate an advantage for EBOV entry and replication early , respectively, in JFB cells. Overall, this study describes filovirus species-sp...

A poultry farm in Maritime Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6361 ____

Sheep, March 2025 One domestic sheep (Ovis aries) tested positive for influenza of avian origin (H5N1) in March 2025 . The case was identified following routine surveillance of farmed livestock on a premises in Yorkshire where highly pathogenic avian influenza (H5N1) had been confirmed in other captive birds . The single animal was a ewe with signs of mastitis but no other clinical signs . The milk was positive by polymerase chain reaction (PCR) and the blood tested positive for H5 antibodies.   All affected birds and the infected ewe were humanely culled to mitigate the risk of further disease spread. Further official testing of the remaining flock of sheep were all negative for the presence of avian influenza virus. Source: DEFRA,  https://www.gov.uk/government/publications/bird-flu-avian-influenza-findings-in-captive-mammals/confirmed-findings-of-influenza-of-avian-origin-in-captive-mammals ____