ETIDIOH - NEW

Abstract Clade 2.3.4.4b H5N1 high pathogenicity avian influenza virus (HPAIV) has caused a panzootic affecting all continents except Australia , expanding its host range to several mammalian species . In March 2024, H5N1 HPAIV was first detected in dairy cattle and goats in the United States . Over 891 dairy farms across 16 states have tested positive until 25th December 2024, with zoonotic infections reported among dairy workers . This raises concerns about the virus undergoing evolutionary changes in cattle that could enhance its zoonotic potential . The Influenza glycoprotein haemagglutinin (HA) facilitates entry into host cells through receptor binding and pH-induced fusion with cellular membranes. Adaptive changes in HA modulate virus-host cell interactions. This study compared the HA genes of cattle and goat H5N1 viruses with the dominant avian-origin clade 2.3.4.4b H5N1 in the United Kingdom , focusing on receptor binding, pH fusion, and thermostability. All the tested H5N1 viru...

Abstract The recent outbreak of highly pathogenic avian influenza (HPAI) in dairy cows has created public health concerns about the potential of consumers being exposed to live virus from commercial dairy products. Previous studies support that pasteurization effectively inactivates avian influenza in milk and an earlier retail milk survey showed viral RNA, but no live virus could be detected in the dairy products tested. Because of the variety of products and processing methods in which milk is used, additional product testing was conducted to determine if HPAI viral RNA could be detected in retail dairy samples, and for positive samples by quantitative real-time RT-PCR (qRT-PCR) further testing for the presence of live virus. Revised protocols were developed to extract RNA from solid dairy products including cheese and butter . The solid dairy product was mechanically liquified with garnet and zirconium beads in a bead beater diluted 1–4 with BHI media. This preprocessing step was su...

Abstract Zoonotic transmission of avian influenza viruses into mammals is relatively rare due to anatomical differences in the respiratory tract between species. Recently, clade 2.3.4.4b highly pathogenic H5N1 avian influenza viruses were detected circulating in North American cattle. Sporadic transmission between cattle, humans, and other animals proximal to cattle or after consuming products from infected cattle has occurred, but thus far there is no evidence of human-to-human transmission . However, the virus has the potential to adapt to the mammalian respiratory tract with every transmission event that occurs, making it crucial to understand cellular and species tropism of the H5N1 2.3.4.4b viruses. We compared viral kinetics of clade 2.3.4.4b viruses isolated from birds and mammals in respiratory epithelial cells derived from cattle, human, swine, and ferret. We found that avian derived viruses could replicate in swine cells only , yet mammalian derived strains could replicate ef...

{Excerpt} Our data indicate that bovine H5N1 viruses can replicate efficiently in the epithelium of the bovine teat cistern, suggesting that they invade the mammary gland through the teat canal , which is more easily accessed by viruses. H5N1 virus is thought to be transmitted among lactating dairy cattle through contaminated milking equipment and/or milker's hands during milking[23]. Proper milking procedures are required to prevent spread of HPAI H5N1 viruses in dairy cattle, thereby minimizing the risk of transmission from cows to other mammals including humans . Source: Emerging Microbes and Infections,  https://www.tandfonline.com/doi/full/10.1080/22221751.2025.2450029#d1e346 _____

 {Summary} At a glance -- H5N1 bird flu is caused by viruses that can infect cows and other animals but most commonly affect birds and poultry .  -- People who work with infected animals or their byproducts (for example, raw milk ), might get sick from the virus.  -- For example , dairy and poultry workers might get sick with H5N1 bird flu.  -- Your employer should develop a workplace health and safety plan and share it with you.  -- CDC updated this page to add information about worker exposure levels (low, medium, and high).  -- We also added detail about how to use the right personal protective equipment safely for each exposure level. (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/bird-flu/prevention/farm-workers.html _____

Abstract In early 2024, an unprecedented outbreak of H5N1 high pathogenicity avian influenza was detected in dairy cattle in the USA . The epidemic remains uncontrolled , with spillbacks into poultry , wild birds and other mammals including humans . Here, we present molecular and virological evidence that the cattle B3.13 genotype H5N1 viruses rapidly accumulated adaptations in polymerase genes that enabled better replication in bovine cells , as well as cells of other mammalian species including humans and pigs . We find evidence of several mammalian adaptations gained early in the evolution of these viruses in cattle including PB2 M631L , which is found in all cattle sequences, and PA K497R, which is found in the majority. Structurally, PB2 M631L maps to the polymerase-ANP32 interface, an essential host factor for viral genome replication. We show this mutation adapts the virus to co-opt bovine ANP32 proteins and thereby enhances virus replication in bovine and primary human airway c...

 {Excerpt, edited} What Highly pathogenic H5N1 avian influenza A virus (HPAI H5N1) remains a low risk to the general public , and public health experts in the United States believe that available treatments and vaccines , as well as those in development, are sufficient to prevent severe disease . However, the National Institutes of Health (NIH) and its federal partners remain focused on monitoring the virus and evaluating changes , according to leading officials at the National Institute of Allergy and Infectious Diseases (NIAID), part of the NIH. In a commentary published in the New England Journal of Medicine , NIAID Director Jeanne M. Marrazzo, M.D., M.P.H., and Michael G. Ison, M.D., M.S ., chief of the Respiratory Diseases Branch in NIAID’s Division of Microbiology and Infectious Diseases, say people should find a balance between enhanced vigilance and “business as usual” with respect to HPAI H5N1 . Since 1996, HPAI H5N1 influenza viruses have circulated in at least 23 countri...

 {Excerpts} SACRAMENTO, the United States -- California's battle against avian influenza A (H5N1) intensified amid spreading infections across dairy farms and a growing number of human infection, including two newly confirmed cases in Stanislaus and Los Angeles counties. The virus, commonly known as bird flu , has infected 659 of California's 984 dairy operations since August, with one-quarter of these cases emerging in the past month alone, according to California authorities. The rapid spread through the state's dairy industry prompted Governor Gavin Newsom to declare a state of emergency last week to protect agricultural workers and public health. (...) The outbreak's human impact has grown increasingly severe , with California reporting at least 36 confirmed cases -- more than half of the nation's total of 65, according to the latest report by the U.S. Centers for Disease Control (CDC) on Tuesday, though the actual count is likely higher as recent local confirma...

Summary   Beyond domestic poultry , influenza A( H5N1 ) of clade 2.3.4.4b has spread to almost all regions , infecting a wide range of wild birds, marine and terrestrial mammals , and recently, cattle in the United States of America . When an influenza virus is circulating in both avian and mammalian populations , the likelihood of spillover to humans and risk to public health may increase . The reported events of the influenza A(H5N1) virus among terrestrial and marine mammals in several countries, including the recent cases detected in the United States of America, have made it necessary to improve virus detection in cattle and other susceptible mammals and closely monitor virus evolution and adaptation to extraordinary hosts . These recommendations aim to support countries in planning surveillance for influenza A(H5N1) in cattle to enhance early detection , to generate evidence-based information to mitigate the impacts of spillover from birds to cattle, and to prevent transmissi...

Assessment based on data as of 18 November 2024   12 December 2024  Key points   At the present time , based on available information , FAO-WHO-WOAH assess the global public health risk of influenza A(H5N1) viruses to be low , while the risk of infection for occupationally exposed persons is low to moderate depending on the risk mitigation measures in place and the local avian influenza epidemiological situation.  Transmission between animals continues to occur and, to date, a growing yet still limited number of human infections are being reported.  Although additional human infections associated with exposure to infected animals or contaminated environments are expected to occur, the overall public health impact of such infections at a global level, at the present time, is minor .  This risk assessment from FAO, WHO, and WOAH updates the assessment of the risk of zoonotic transmission (for example, animal to human) considering additional information made a...

Abstract The emergence of highly pathogenic avian influenza (HPAI) A H5N1 virus in dairy cattle marks a troubling new chapter in the ongoing battle against zoonotic diseases . Since its initial detection in 1955, the H5N1 virus has primarily been associated with poultry , posing significant threats to both animal and human health . However, recent outbreaks in U.S. dairy herds across nine states have revealed an alarming expansion of the virus , with over 190 herds affected as of September 2024. This unprecedented spread in cattle has sparked intense concern among scientists and health officials, especially with reports indicating that up to 20% of dairy products may contain traces of the virus . The implications of the H5N1 virus establishing itself in cattle populations are profound. This potential endemic presence could transform dairy farms into reservoirs of the virus , facilitating its evolution and increasing the risk of human transmission . Mutations enhancing viral replication...

According to CCTV News, on December 18 local time, California Governor Gavin Newsom declared a state of emergency in California to deal with the increasingly serious avian influenza epidemic . Although there have been no cases of human-to-human transmission in California , 61 people have been infected with avian influenza in the United States, 34 of which are from California . Newsom emphasized that although the risk is low, the government will continue to take necessary measures to prevent the spread of the virus and open funds to support the emergency response of relevant agencies. According to Xinhua News Agency, the U.S. Centers for Disease Control and Prevention issued a statement on the 18th saying that the United States reported the first severe case of human infection with the H5N1 avian influenza virus . The patient was hospitalized and his infection may be related to contact with sick and dead poultry raised in private backyard farms. The CDC said in a statement that the pati...

 {Excerpt} Abstract   Between 21 September and 6 December 2024 , 657 highly pathogenic avian influenza (HPAI) A(H5N1) and A(H5N5) virus detections were reported in domestic (341) and wild (316) birds across 27 countries in Europe . Many HPAI outbreaks in domestic birds were clustered in areas with high poultry density and characterised by secondary farm-to-farm spread . Waterfowl , particularly the mute swan , were primarily affected during this reporting period, with HPAI virus detections focused on south-eastern Europe . Notably, A(H5N5) viruses expanded their geographic and host range, resulting in a surge in detections and mortality events described in gulls and crows . No new HPAI virus detections in mammals were reported in Europe during this reporting period, but the number of dairy cattle farms reportedly affected in the United States of America (USA) rose to > 800 in 16 States, and HPAI virus was identified in two pigs in a mixed-species farm. Between 21 September ...

In an update on the mutating virus - known as H5N1 – Dr. Madhur Dhingra from the Food and Agriculture Organization, FAO, said that it had “spilled over into wildlife”.  More than 500 bird species have been infected along with at least 70 mammalian species , including the endangered California condor and polar bears .  In regions that are heavily reliant on poultry as a primary source of protein, the FAO medic insisted that avian influenza “poses a serious threat to food and nutrition security”. Economic damage Dr Dhingra warned that hundreds of millions of people’s livelihoods have been affected by the virus – an economic burden on farmers that could prevent them from investing in adequate biosafety measures. Following the emergence of H5N1 influenza virus in dairy cattle , the WHO has joined calls for strengthened surveillance and biosecurity on farms, to keep animals and people safe. The UN health agency said that in 2024, 76 people have been infected with the H5 avian influ...

Abstract Highly pathogenic avian influenza (HPAI) viruses with H5 hemagglutinin (HA) genes (clade 2.3.4.4b) are causing an ongoing panzootic in wild birds . Circulation of these viruses is associated with spillover infections in multiple species of mammals , including a large, unprecedented outbreak in American dairy cattle . With limited testing of dairy herds, there is an unmet need for genomic surveillance . Infected cattle can shed high amounts of HPAI H5N1 viruses in milk , allowing detection in pasteurized retail dairy samples. Over a 2-month sampling period in one Midwestern city , we obtained dairy products processed in 20 different states . Here we demonstrate that a tiled-amplicon sequencing approach produced over 90% genome coverage at greater than 20x depth from 5 of 13 viral RNA positive samples. A combination of RT-qPCR testing and sequencing from retail dairy prod- ucts can be a useful component of a One Health framework for responding to the avian influenza outbreak in ...