Novel introductions of #human-origin #H3N2 #influenza viruses in #swine, #Chile

Abstract

Influenza A virus (IAV) continuously threatens animal and public health globally, with swine serving as a crucial reservoir for viral reassortment and evolution. In Chile, H1N2 and H3N2 subtypes were introduced in the swine population before the H1N1 2009 pandemic, and the H1N1 was introduced from the H1N1pdm09 by successive reverse zoonotic events. Here, we report two novel introductions of IAV H3N2 human-origin in Chilean swine during 2023. Our study reveals a closer relationship between recent human seasonal H3N2 and novel swine strains. Interestingly, one strain maintains all the genes from the original human virus, but the other strain is already a reassortment of human H3N2 and an H1N2 previously observed on the farm. Observing global IAV sequences, a similar pattern was identified in the USA confirming the reverse zoonotic potential of current seasonal human H3N2 strains. These results highlight the importance of ongoing surveillance and reinforcing biosecurity in swine farms. These findings raise questions about their potential impact on viral dynamics in the swine population and public health, underscoring the need for further investigation into the origin and evolutionary dynamics of this emerging swine H3N2 reassortant virus.

Source: Frontiers in Veterinary Medicine, https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2024.1505497/full

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Phylogeography and biological characterization of #H12N2 virus isolated from whooper #swan in Central #China

Abstract

Wild birds and waterfowl serve as the natural reservoirs of avian influenza viruses (AIVs). When AIVs originating from wild birds cross species barriers to infect mammals or humans, they pose a significant threat to public health. The H12 subtype of AIVs primarily circulates in wild birds, with relatively few isolates reported worldwide, and the evolutionary and biological characteristics of H12 subtype AIVs remain largely unknown. In this study, we analyzed the spatiotemporal distribution of H12 subtype AIVs worldwide and conducted a comprehensive investigation into the evolutionary and biological characteristics of an H12N2 virus isolated from a whooper swan in Central China. Phylogenetic analysis revealed that the H12N2 isolate belongs to the Eurasian lineage, with its HA gene likely originating from a duck-derived H12N5 virus and its NA gene potentially derived from an H9N2 virus, indicating that it is a complex reassorted virus. Animal experiments in domestic ducks and chickens demonstrated that the virus replicates at low levels in the respiratory tract of poultry and exhibits moderate horizontal transmission in ducks. However, it is capable of efficient horizontal transmission in chickens. Mouse infection experiments revealed that the virus could be detected in the nasal turbinates and lungs of mice, indicating that the H12N2 virus can infect mice without prior adaptation. In vitro studies revealed that the virus replicates efficiently in MDCK cells, with significantly higher titers than those in DF1 cells. These findings, combined with the mouse infection results, suggest that the H12N2 virus poses a potential risk of mammalian infection. This study provides valuable insights regarding the characteristics of the H12N2 virus and highlights the importance of ongoing surveillance and risk assessment of AIVs originating from wild birds.

Source: Frontiers in Microbiology, https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1536876/full

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#USA, Monitoring for Avian #Influenza A(#H5) Virus In #Wastewater (Jan 12-18 '25)

 {Excerpt}

Time Period: January 12 - January 18, 2025

-- H5 Detection: 35 sites (10.4%)

-- No Detection: 301 sites (89.6%)

-- No samples in last week: 62 sites

(...)

Source: US Centers for Disease Control and Prevention, https://www.cdc.gov/bird-flu/h5-monitoring/index.html

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#Portugal - #Influenza A #H5N1 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

 Unspecified domestic birds in Leiria Region.

Source: WOAH, https://wahis.woah.org/#/in-review/6214

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#Antiviral activity of #tecovirimat against #monkeypox virus clades 1a, 1b, 2a, and 2b

{Excerpt}

The zoonotic Orthopoxvirus monkeypox virus includes two main clades (ie, 1 and 2) relevant to human transmission.1 Two major outbreaks of monkeypox virus have occurred since 2022,1–3 and were declared public health emergencies of international concern by WHO in July, 2022, and August, 2024. The first outbreak was caused by a clade 2b strain that quickly spread worldwide, resulting in approximately 100 000 cases and 200 deaths.3 In the second outbreak, the novel clade 1b emerged.4 As of December, 2024, this upsurge has resulted in more than 55 000 reported or suspected cases and approximately 1000 deaths in DR Congo and neighbouring countries, including Burundi, Rwanda, Uganda, and Angola.4 A few imported clade 1b cases have also been reported in the UK, Sweden, Germany, Belgium, France, the USA, Canada, and Thailand.5 Prevention measures include patient isolation and care as well as vaccines.

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Source: Lancet Infectious Diseases, https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(25)00014-3/fulltext?rss=yes

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Characterization of novel highly pathogenic avian #influenza A(#H5N6) clade 2.3.4.4b virus in wild #birds, East #China, 2024

{Excerpt}

Dear Editor,

The highly pathogenic avian influenza viruses (HPAIVs) are important epizootic and zoonotic pathogens that cause significant economic losses to the poultry industry and pose a serious risk to veterinary and public health. Wild birds have been recognized as the primary reservoirs for influenza A virus, and some species show little sign of clinical disease or even can be asymptomatic during long distance carriers of the virus (Lycett et al., 2019). Since it was first discovered in 1959, the H5Nx HPAIVs have spread globally and cause outbreaks in wild birds, poultry and sporadic human and other mammalian infections (Lycett et al., 2019). Due to the reassortant events of diverse strains facilitated by migratory waterfowl, the clade 2.3.4.4 of H5Nx viruses acquiring neuraminidase (NA) gene from other low pathogenicity avian influenza viruses (LPAIVs) emerged in 2014 and gradually became the dominant sub-clade (Lee et al., 2017). The genetic diversity of clade 2.3.4.4 of H5Nx hemagglutinin (HA) has further evolved into eight subclades (2.3.4.4a to 2.3.4.4h) according to a unified nomenclature (Graziosi et al., 2024). H5N6 of clades 2.3.4.4d-h were predominantly identified in China from 2014 to early 2020 until the occurrence of a novel H5N6 derived the clade 2.3.4.4b HA gene of H5N8 in December 2020 (Gu et al., 2022). Subsequently, the preponderant clade of the H5N6 subtype HPAIV in China switched into 2.3.4.4b. Recently, novel H5N6 HPAIVs containing HA gene from clade 2.3.4.4b H5N1 virus entered R. O. Korea, with disease outbreaks in poultry and wild bird mortality events (Cho et al., 2024; Heo et al., 2024).

(...)

Source: Virologica Sinica, https://www.sciencedirect.com/science/article/pii/S1995820X25000021?via%3Dihub

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#Receptor #binding, #structure, and #tissue #tropism of #cattle-infecting #H5N1 avian #influenza virus #hemagglutinin

Summary

The ongoing circulation of highly pathogenic avian influenza (HPAI) A (H5N1) viruses, particularly clade 2.3.4.4b strains, poses a significant threat to animal and public health. Recent outbreaks in cattle highlight concerns about cross-species transmission and zoonotic spillover. Here, we found that the hemagglutinin (HA) protein from a cattle-infecting H5N1 virus has acquired slight binding to human-like α2-6-linked receptors while still exhibiting a strong preference for avian-like α2-3-linked sialic acid receptors. Immunohistochemical staining revealed HA binding to bovine pulmonary and mammary tissues, aligning with clinical observations. HA also binds effectively to human conjunctival, tracheal, and mammary tissues, indicating a risk for human transmission, notably in cases of conjunctivitis. High-resolution cryo-electron microscopy (cryo-EM) structures of this H5 HA in complex with either α2-3 or α2-6 receptors elucidate the molecular mechanisms underlying its receptor-binding properties. These findings provide critical insights into the tropism and transmission potential of this emerging pathogen.

Source: Cell, https://www.cell.com/cell/abstract/S0092-8674(25)00048-0

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The sweet side of #H5N1 #influenza virus #infection

Summary

H5Nx viruses remain a threat to human health. Over the past few years, the H5Nx clade 2.3.4.4b has rapidly spread to 6 continents, leading to massive avian and mammalian host deaths. In late March 2024, H5N1 was first identified in lactating dairy cows in the United States and has spread to 16 states, affected hundreds of herds, and caused over 50 known human infections. In this review, we discuss the origins of 2.3.4.4b H5N1 viruses and how they are evolving to better infect mammals, with an emphasis on receptor-binding characteristics. Understanding changes in receptor binding and mutations in the viral genome that allow for sustained spread in mammals can inform public health measures and prevent future influenza virus epidemics and pandemics.

(...)

Source: PLoS Pathogens, https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1012847

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Exotic and #Zoological #Birds Resident and Imported into #Nigeria harbour Highly Pathogenic Avian #Influenza Virus: #Threat to #Poultry Production, Food security and Public Health.

Abstract

Influenza is a major infectious disease challenge affecting animal and human health globally, and wild birds are historically the primary reservoirs of all the known Influenza A virus subtypes. Here, we detected the Highly Pathogenic Avian Influenza (HPAI) virus in exotic and aquatic birds in three different locations in Nigeria. On the 8th of February 2021, exotic birds: Yellow Golden Pheasant (Chrysolophus pictus), Sultan chicken (Gallus gallus domesticus), Lakenvelder chicken (Gallus gallus domesticus), and Common pheasant (Phasianus calchicus), imported from Libya and transported across the Niger Republic border to Nigeria, were presented to the National Veterinary Research Institute, Vom, for screening. Also, a family in Lagos State bought some exotic aquatic birds from a live bird market in Sokoto State, Nigeria, where sudden death was recorded with the birds showing few clinical signs. Similarly, the sudden death of some aquatic birds was reported in Mandela Parks and Gardens in Asaba, Delta State, few weeks after some captured wild birds were introduced to the Park and Gardens. Oropharyngeal, cloacal, and tissue samples were all collected from the reported cases. Total viral nucleic acid was extracted and screened for Influenza A viruses using real-time RT-PCR. The HPAI viruses H5N1 and H5N8 were detected in the imported aquatic (geese and ducks) and exotic (yellow golden pheasant) birds. The samples tested negative for low-pathogenic Avian Influenza Virus (H9N2) as well as other avian viruses, viz., Avian avulavirus-1 (Newcastle disease Virus) and infectious bronchitis virus. This highlights the role of these resident and imported exotic birds in the local transmission and spread of the HPAI virus to domestic poultry. The findings call for proper biosecurity and quarantine measures for exotic and wild birds to reduce the potential risk to animal and public health in Nigeria.

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2025.01.22.634354v1

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#UK - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification, 3rd

A 1.4 million egg laying and rearing flock. Increased mortality and other clinical signs were reported. Samples taken tested positive for HPAI H5N1. England, Shropshire Region.

Source: WOAH, https://wahis.woah.org/#/in-review/6209

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#UK - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification, 2nd

A 13,316 commercial turkey fattening unit. Increased mortality and other clinical signs were reported. Samples taken and tested positive for HPAI H5N1. England, East Riding of Yorkshire Region.

Source: WOAH, https://wahis.woah.org/#/in-review/6206

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#UK - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification

A 240 free-range layer unit. Increased mortality and other clinical signs were reported. Samples taken and tested positive for HPAI H5N1. England, East Sussex Region.

Source: WOAH, https://wahis.woah.org/#/in-review/6207

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Chronic Systemic #SARS-CoV-2 #Infection Without Respiratory Involvement in an Immunocompromised Patient

Abstract

In a patient on immunosuppressant treatment, SARS-CoV-2 RNA was documented in different extra-respiratory samples over several months in the absence of positive determinations in upper respiratory samples. Whole-genome sequencing of these samples showed the acquisition of different single-nucleotide polymorphisms over time, suggesting viral evolution and thus viral viability.

Source: Viruses, https://www.mdpi.com/1999-4915/17/2/147

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Association of #poultry #vaccination with interspecies #transmission and molecular #evolution of #H5 subtype avian #influenza virus

Abstract

The effectiveness of poultry vaccination in preventing the transmission of highly pathogenic avian influenza viruses (AIVs) has been debated, and its impact on wild birds remains uncertain. Here, we reconstruct the movements of H5 subtype AIV lineages among vaccinated poultry, unvaccinated poultry, and wild birds, worldwide, from 1996 to 2023. We find that there is a time lag in viral transmission among different host populations and that movements from wild birds to unvaccinated poultry were more frequent than those from wild birds to vaccinated poultry. Furthermore, our findings suggest that the HA (hemagglutinin) gene of the AIV lineage that circulated predominately in Chinese poultry experienced greater nonsynonymous divergence and adaptive fixation than other lineages. Our results indicate that the epidemiological, ecological, and evolutionary consequences of widespread AIV vaccination in poultry may be linked in complex ways and that much work is needed to better understand how such interventions may affect AIV transmission to, within, and from wild birds.

Source: Science Advances, https://www.science.org/doi/10.1126/sciadv.ado9140

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#USA, #H5N1 #birdflu is getting worse, but #Trump has silenced the #CDC

{Excerpts}

(...)

The U.S. Department of Health and Human Services (HHS) has issued a gag order to the CDC, FDA and other departments by its acting secretary, informing them to terminate external communications before February 1, except for serious situations related to health and safety.

What do the FDA and CDC usually say? Nothing much, nothing that affects people's livelihood. They just send out a press release to tell everyone that a new drug has been approved, or issue new regulations, such as the previous rule that prohibits the use of red dye No. 3 in food. If it hadn't been released before Trump took office, it would not be released now.

There is even less content worth reading about the CDC, which only talks about the latest epidemics and how to deal with them, which are obviously not important. How can it be more important than the virtual currency issued by Trump's family?

HHS is the Department of Health and Human Services, and releasing information to the public is clearly neither healthy nor in the service of the public.

But here I have to defend Trump a little. When the US government is changing hands, it is not uncommon for the new government to ask all departments to temporarily stop external communications, mainly to ensure a smooth handover and avoid communication errors. However, this time is generally short, and the banned content is strictly limited, not a complete ban.

For presidents like Trump to impose a two-week ban on all visitors, it shows that previous presidents were not very smart. No one would have thought that they could do this.

Of course, now that the United States has the return of the wise and powerful President Trump, the situation is not just good, it is very good. No, it is not even very good, it is extremely good. Under such a gratifying situation, the CDC and other infectious disease control departments really have nothing to inform everyone.

For example, the CDC has a publication called Morbidity and Mortality Weekly Report. This is the worst kind of shit. It is updated every week and tells you how many people have died from this disease or what virus has been found. AIDS was first recorded in the Morbidity and Mortality Weekly Report.

Once the gag order is issued, the Morbidity and Mortality Weekly Report should also be suspended for at least two issues. I don't think there will be anything important in these two issues. It's just that the H5N1 highly pathogenic avian influenza is getting worse in the United States.

Originally, there should have been important updates in this regard in the Morbidity and Mortality Weekly Report in the next two weeks, but such trivial matters and a few broken viruses cannot cause any trouble. With Trump around, he is like a god protecting him.

Although the FDA just announced last Friday that it would inspect pet food safety because cat food was contaminated with H5N1 and more than a dozen pet cats across the United States became seriously ill or died, under Trump's command, the WHO was kicked out and the CDC was banned. I believe H5N1 will soon realize how powerful the United States is.

(...)

Source: NetEase, https://m.163.com/dy/article/JMIUM39E0552CSHY.html

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Integrating #macroeconomic and public #health impacts in #social planning #policies for #pandemic response

Abstract

Infectious disease outbreaks with pandemic potential present challenges for mitigation and control. Policymakers make decisions to reduce disease-associated morbidity and mortality while also minimizing socioeconomic costs of control. Despite ongoing efforts and widespread recognition of the challenge, there remains a paucity of decision tool frameworks that integrate epidemic and macroeconomic dynamics. Here, we propose and analyze an econo-epidemic model to identify robust planning policies to limit epidemic impacts while maintaining economic activity. The model couples epidemic dynamics, behavioral change, economic activity, and feasible policy plans informed by respiratory disease threats of pandemic concern. We compare alternative fixed, dynamic open-loop optimal control, and feedback control policies via a welfare loss framework. We find that open loop policies that adjust employment dynamically while maintaining a flat epidemic curve in advance of the uncertain arrival of population-scale vaccination outperform fixed employment reduction policies. However, open loop policies are highly sensitive to misestimation of parameters associated with intrinsic disease strength and feedback between economic activity and transmission, leading to potentially significant increases in welfare loss. In contrast, feedback control policies guided by open loop dynamical targets of the time-varying reproduction number perform near-optimally when parameters are well-estimated, while significantly outperforming open loop policies whenever disease features and population-scale behavioral response are misestimated -- as they inevitably are. These findings present a template for integrating principled economic models with epidemic scenarios to identify vulnerabilities in policy responses and expand policy options in preparation for future pandemics.

Source: MedRxIV, https://www.medrxiv.org/content/10.1101/2025.01.21.25320900v1

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Collection of Avian #Influenza-Impacted #Wildlife in #Delaware Expanded Through DNREC-USDA Wildlife Services Effort

 {Excerpt}

DOVER, Del. (Jan. 22, 2025) – The Delmarva Avian Influenza Joint Information Center announced today that the Delaware Department of Natural Resources and Environmental Control (DNREC) and the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) Wildlife Services are collaborating to collect sick and deceased snow geese and other wild birds that may have succumbed to the outbreak of avian influenza currently spreading throughout the state. 

The expanded statewide collection effort to help track the bird flu is funded through DNREC and the Delaware Department of Agriculture (DDA).

Sick or dead wild animals found in Delaware during the avian influenza outbreak or at any time of year, are to be reported to the DNREC Wildlife Section. 

Reporting deceased or ill wildlife does not guarantee that DNREC and APHIS Wildlife Services will respond to every report, only that a DNREC or APHIS Wildlife Services representative will assess the report, and if additional information is needed, may make follow-up contact.

State authorities also reiterated that the public should not pick up or handle any sick birds. 

Dead birds should not be picked up unless disposable plastic gloves are worn to handle them. This guidance also applies to waterfowl hunters – as the DNREC Wildlife Section has been made aware of hunters examining their harvest then moving ducks or geese to a game bag or carrying strap without following recommended precautions for wild birds that might have contracted avian influenza.

-- Anyone encountering sick or dead wild birds on private or public property should report their findings immediately to State authorities.

-- Report sightings of sick or dead wild birds through the DNREC Division of Fish and Wildlife’s sick, injured or dead wildlife reporting form.

-- Notify DDA if you find sick or dead poultry on your farm at poultry.health@delaware.gov.

If a resident finds a dead wild bird on their property and wants to remove it themselves, they should wear proper personal protective equipment (PPE), including gloves, a mask, and safety glasses, to dispose of it. 

Double-bag each dead bird found, zip-tie the bag and put it in the trash bin for pickup and disposal at a Delaware Solid Waste Authority landfill. 

Residents are also advised to carefully remove and dispose of all PPE in the dedicated trash bags and always wash their hands afterward.

Additionally, waterfowl hunters are advised to follow more focused protocols from APHISOpen this document with ReadSpeaker docReader for handling and field dressing any wild fowl they harvest in Delaware during an avian influenza outbreak.

Avian influenza is a highly contagious airborne respiratory virus that spreads quickly among birds through nasal and eye secretions and manure. 

Snow geese, which are waterfowl, are known to migrate from the Arctic and form large flocks in Delaware each winter. 

Due to close contact with thousands of other snow geese while feeding and roosting, they can get sick and die. 

It is unknown when or where the snow geese may have acquired the virus given their highly migratory nature and association with other waterfowl and waterbirds throughout the Atlantic Flyway through which they travel into Delaware and more southern states.

While the H5N1 virus has infected a small number of people across the U.S., there is no documented transmission of the virus between people in this country. Though the continued testing of people in close contact with animals infected with HPAI indicates a low risk to the general public’s health, children and pets should be kept away from wild birds and bird droppings.

If anyone in contact with wild birds or poultry begins to experience flu-like symptoms, please contact the Delaware Division of Public Health Office of Infectious Disease Epidemiology at 888-295-5156 (after hours) or 302-744-4990 (business hours) for a referral to a DPH clinic to obtain a flu swab test. 

Flu-like symptoms include fever, cough, sore throat, congestion, body aches, fatigue, and sometimes diarrhea. If symptoms seem severe, including trouble breathing, chest pain or pressure, dizziness/confusion, severe muscle pain, seizure, severe weakness or unsteadiness, worsening of chronic medical conditions, or fever or cough that begin to improve and then worsen or return, please dial 911 or visit the emergency department. Let hospital staff and providers know if you have been exposed to poultry or wild birds.

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Source: Department of Health, https://news.delaware.gov/2025/01/22/collection-of-avian-influenza-impacted-wildlife-in-delaware-expanded-through-dnrec-usda-wildlife-services-effort/

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Lack of Competence of #US #Mosquito Species for Circulating #Oropouche Virus

Abstract

Given recent outbreaks of Oropouche virus in Latin America and >100 confirmed travel-associated cases in the United States, we evaluated the competence of US vectors, including Aedes albopictus, Culex quinquefasciatus, Culex pipiens, and Anopheles quadrimaculatus mosquitoes. Results with historic and recent isolates suggest transmission potential for those species is low.

Source: Emerging Infectious Diseases Journal, https://wwwnc.cdc.gov/eid/article/31/3/24-1886_article

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Phylogeographic Characterizations of Recent (2015–2023) #Senecavirus A Isolates from #Canada

Abstract

Senecavirus A (SVA) continues to cause vesicular lesions in swine in Canada and many regions worldwide. Since the vesicular lesions caused by SVA are similar to those caused by foot and mouth disease virus, swine vesicular disease virus and vesicular stomatitis virus, a foreign animal disease investigation must be initiated to rule out these diseases. SVA isolates from pigs displaying vesicular lesions in Canada from 2015 to 2023 were sequenced, and phylogeographic analysis was performed using the complete genome sequences. The results infer that SVA has spread between the United States and Canada several times. In addition, the results suggest that SVA spreads from different regions. SVA spread was inferred from Canada into Thailand, India and Mexico and inferred from the United States to Brazil, Columbia, Chile and China with ten separate introductions. Furthermore, recombination was observed in SVA genomes from Canada, the United States and China.

Source: Viruses, https://www.mdpi.com/1999-4915/17/2/141

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Geographical #distribution and evolutionary #dynamics of #H4Nx avian #influenza viruses

Abstract

H4Nx avian influenza viruses (AIVs) have been isolated from wild birds and poultry and can also cross the species barrier to infect mammals (pigs and muskrats). The widespread presence of these viruses in wild birds and poultry and their ability to be transmitted interspecies make them an undeniable hazard to the poultry farming industry. In the present study, we collected fecal and swab samples from wild birds and poultry in Guangdong Province from January 2019 to March 2024, and various subtypes of AIVs were isolated, including 19 strains of H4 subtype AIVs. Further analysis was conducted on the internal genes of the 19 strains. These strains clustered together with high homology to highly pathogenic avian influenza virus (HPAIV), suggesting that H4Nx AIV may be reassorted from HPAIV. Two H4N8 strains are phylogenetically related to the porcine H4N8 AIV. Molecular characterization revealed that all viruses in this study were less pathogenic but had potential mammalian-adapted mutations. The transmission dynamics of H4Nx AIVs revealed that Europe and Asia, especially the Netherlands and Bangladesh, may be the centers of transmission. This may be linked to the migration of wild birds. The high migration rates from Russia to the Netherlands and from Russia to Bangladesh may also play a role. Therefore, continuous and systematic monitoring of wild birds to clarify the spatial and temporal distribution and prevalence of influenza viruses in wild birds is significant for early warning of avian influenza outbreaks in poultry and for risk assessment for public health and safety.

Source: Frontiers in Microbiology, https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1505203/full

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