Avian influenza overview December 2023–March 2024

EFSA Journal, Journal Year: 2024, Volume and Issue: 22(3)

Published: March 1, 2024

Between 2 December 2023 and 15 March 2024, highly pathogenic avian influenza (HPAI) A(H5) outbreaks were reported in domestic (227) wild (414) birds across 26 countries Europe. Compared to previous years, although still widespread, the overall number of HPAI virus detections was significantly lower, among other reasons, possibly due some level flock immunity previously affected bird species, resulting reduced contamination environment, a different composition circulating A(H5N1) genotypes. Most poultry primary following introduction by birds. Outside Europe, majority clustered North America, while spread more naïve populations on mainland Antarctica is particular concern. For mammals, A(H5N5) for first time goat kids United States America represented natural infection ruminants. Since last report as 12 five human infections, including one death, three which clade 2.3.2.1c viruses, have been Cambodia. China has two fatal case, with A(H5N6), four infections A(H9N2) case co-infection seasonal A(H3N2) A(H10N5). The latter documented Human remain rare no sustained human-to-human observed. risk currently H5 viruses 2.3.4.4b Europe remains low general population EU/EEA. moderate those occupationally or otherwise exposed infected animals.

Language: Английский

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Avian influenza A (H5N1) virus in dairy cattle: origin, evolution, and cross-species transmission

mBio, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 13, 2024

Since the emergence of highly pathogenic avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b as a novel reassortant from subtype H5N8, has led to massive number outbreaks worldwide in wild and domestic birds. Compared parental HPAIV H5N8 2.3.4.4b, displayed an increased ability escape species barriers infect multiple mammalian species, including humans. The host range been recently expanded include ruminants, particularly dairy cattle United States, where cattle-to-cattle transmission was reported. As with 2.3.4.4.b viruses, cattle-infecting found transmit other contact animals cats, raccoons, rodents, opossums, poultry. Although replication cows appears be mainly confined mammary tissue, high levels viral loads detected milk, infected cats poultry showed severe respiratory disease, neurologic signs, eventually died. Furthermore, several human infections have also reported farm workers were attributed exposures cattle. This is believed represent first mammalian-to-human report H5N1. Fortunately, infection humans cows, opposed animals, mild most cases. Nevertheless, bovine outbreak represents largest mammal close humans, increasing risk that this already adapted further adapts human-to-human starts pandemic. Herein, we discuss epidemiology, evolution, pathogenesis, potential impact identified States. Eventually, interdisciplinary cooperation under One Health framework required able control ongoing stop it before expansion its geographical distribution.

Language: Английский

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Avian influenza overview March–June 2024

EFSA Journal, Journal Year: 2024, Volume and Issue: 22(7)

Published: July 1, 2024

Abstract Between 16 March and 14 June 2024, 42 highly pathogenic avian influenza (HPAI) A(H5) virus detections were reported in domestic (15) wild (27) birds across 13 countries Europe. Although the overall number of Europe has not been this low since 2019–2020 epidemiological year, HPAI viruses continue to circulate at a very level. Most poultry due indirect contact with birds, but there was also secondary spread. Outside Europe, situation intensified particularly USA, where new A(H5N1) genotype (B3.13) identified >130 dairy herds 12 states. Infection cattle appears be centred on udder, milk from infected animals showing high viral loads representing vehicle transmission. Apart cattle, two other mammal species (alpaca walrus) for first time. 20 human cases infection Vietnam (one A(H5N1), one A(H9N2)), Australia (with travel history India, A(H5N1)), USA (three China (two A(H5N6), three A(H9N2), A(H10N3)), India Mexico fatal A(H5N2) case). The latter case laboratory‐confirmed subtype A(H5N2). had exposure poultry, live markets, or prior detection onset illness. Human infections remain rare no human‐to‐human transmission observed. risk currently circulating clade 2.3.4.4b remains general public EU/EEA. low‐to‐moderate those occupationally otherwise exposed contaminated environments.

Language: Английский

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The avian and human influenza A virus receptors sialic acid (SA)-α2,3 and SA-α2,6 are widely expressed in the bovine mammary gland

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: May 3, 2024

Abstract An outbreak of H5N1 highly pathogenic influenza A virus (HPIAV) has been detected in dairy cows the United States. Influenza (IAV) is a negative-sense, single-stranded, RNA that not previously associated with widespread infection cattle. As such, cattle are an extremely under-studied domestic IAV host species. receptors on cells sialic acids (SAs) bound to galactose either α2,3 or α2,6 linkage. Human IAVs preferentially bind SA-α2,6 (human receptor), whereas avian have preference for (avian receptor). The receptor can further be divided into two receptors: isolated from chickens generally more tightly SA-α2,3-Gal-β1,4 (chicken duck SA-α2,3-Gal-β1,3 (duck We found all were expressed, different degree, mammary gland, respiratory tract, and cerebrum beef and/or human widely expressed bovine chicken dominated tract. In general, only low expression was observed neurons cerebrum. These results provide mechanistic rationale high levels reported infected milk show potential act as mixing vessel novel generation. Graphical abstract Created Biorender.com

Language: Английский

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Preparedness, prevention and control related to zoonotic avian influenza

EFSA Journal, Journal Year: 2025, Volume and Issue: 23(1)

Published: Jan. 1, 2025

A risk assessment framework was developed to evaluate the zoonotic potential of avian influenza (AI), focusing on virus mutations linked phenotypic traits related mammalian adaptation identified in literature. Virus sequences were screened for presence these and their geographical, temporal subtype-specific trends. Spillover events mammals (including humans) human seroprevalence studies also reviewed. Thirty-four associated with five (increased receptor specificity, haemagglutinin stability, neuraminidase enhanced polymerase activity evasion innate immunity) shortlisted. AI viruses (AIVs) carrying multiple adaptive belonged both low highly pathogenic subtypes, mainly A(H9N2), A(H7N9), A(H5N6) A(H3N8), sporadic primarily detected Asia. In EU/EEA, H5Nx clade 2.3.4.4b, which have increased opportunities evolution due widespread circulation birds occasional cases/outbreaks mammals, acquired highest number traits. Adaptive traits, such as immune evasion, frequently acquired, while receptor-specific remained rare. Globally, cases remain rare, majority overall A(H5N1), A(H5N6), A(H7N9) A(H9N2) that are among subtypes tend a higher The main drivers include host characteristics, external factors increasing AIV exposure humans wild domestic (e.g. activities ecological factors). Comprehensive surveillance AIVs targeting whole genome sequencing animals is essential early detection efficient implementation control measures. All preparedness, preventive measures must be implemented under One Health tailored setting epidemiological situation; particular, monitoring, biosecurity, genomic global collaboration critical mitigating risks AIV.

Language: Английский

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Clade 2.3.4.4b H5N1 neuraminidase has a long stalk, which is in contrast to most highly pathogenic H5N1 viruses circulating between 2002 and 2020

mBio, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 26, 2025

ABSTRACT Since 2020, H5N1 highly pathogenic avian influenza (HPAI) viruses of clade 2.3.4.4b have been rapidly spreading in wild birds but also caused a large number mammalian infections and more than 70 known human cases. Importantly, this has crossed the species barrier into dairy cattle US late 2023/early 2024. The neuraminidase (NA) protein N1 subtype can feature truncations its stalk domain, which identified as putative virulence factors poultry seem to negative impact on transmission mammals. emergence, vast majority HPAI A/goose/Guangdong/1/1996-lineage isolates featured truncated version NA domain. Here, we report that changed with 2020 expansion isolates—including strains circulating cattle—feature long IMPORTANCE While domain may be associated increased poultry, transmissibility is currently globally features neuraminidase, increase risk for these become human-to-human transmissible.

Language: Английский

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Cats as sentinels of mammal exposure to H5Nx avian influenza viruses: a seroprevalence study, France, December 2023 to January 2025

Eurosurveillance, Journal Year: 2025, Volume and Issue: 30(12)

Published: March 27, 2025

Circulation of clade 2.3.4.4b highly pathogenic avian influenza H5Nx viruses has intensified in recent years, increasing epizootics and mammalian exposure. Cats, bridging wild domestic environments, are key for studying cross-species transmission. To assess their exposure France, we screened 728 outdoor cats (December 2023-January 2025). Seropositivity was 2.6% (19/728), with an estimated seroprevalence at 1.8%. Absence hunting behaviour a significant protective factor. These findings highlight high the need targeted surveillance cats.

Language: Английский

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The mammary glands of cows abundantly display receptors for circulating avian H5 viruses

Journal of Virology, Journal Year: 2024, Volume and Issue: 98(11)

Published: Oct. 10, 2024

ABSTRACT Influenza A viruses (IAVs) from the H5N1 2.3.4.4b clade are circulating in dairy farms USA.; ruminants were presumed not to be hosts for IAVs. Previously, IAV-positive mammalian species hunters and scavengers, possibly getting infected while feeding on birds. It is now recognized that circulate US cattle transmit through a mammary gland route, contrast transmission by aerosols via respiratory tract. The sialome cow tract so far solely defined using plant lectins. Here, we used recombinant HA proteins representing current classical H5 determine distribution of IAV receptors tissues cows. We complemented our study mapping glycan upper lower tracts horses pigs. Most lined with sialic acid modifications, such as N-glycolyl O-acetyl, which bound IAV. Interestingly, protein isolates significantly gland, whereas failed do so. Furthermore, 9-O-acetyl modification prominent all tested, 5-N-glycolyl not, resulting display avian hemagglutinins. This could explain high levels virus found these milk, adding supporting data this route. IMPORTANCE influenza viruses, usually affect birds, have been USA. Surprisingly, spreading among cows, there possibility they spread air but their milk glands. To understand better, studied how attaches cow’s glands specific viral proteins. cow-associated binds strongly glands, unlike older versions infecting might why suggesting new way spreading.

Language: Английский

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Panzootic HPAIV H5 and risks to novel mammalian hosts

npj Viruses, Journal Year: 2024, Volume and Issue: 2(1)

Published: May 29, 2024

The H5 subtype of highly pathogenic avian influenza viruses represents a significant challenge to animal and human health. clade 2.3.4.4b have experienced an unprecedented global spread, coupled with remarkable genetic plasticity for adaptation in birds mammals. Although infections remain very limited, the establishment wild, marine, farmed animals, including recently dairy cattle, is concern. role mammalian hosts as intermediaries zoonotic or even pandemic A should not be underestimated. In order mitigate risk adequately prepared, it essential understand monitor dynamics HPAIV at avian-mammal interface.

Language: Английский

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Risk factors for the incursion of highly pathogenic avian influenza virus into poultry and other captive bird holdings in Denmark from 2020 to 2023: a case-control study

Preventive Veterinary Medicine, Journal Year: 2025, Volume and Issue: 236, P. 106419 - 106419

Published: Jan. 5, 2025

Highly pathogenic avian influenza (HPAI) is a major concern in terms of animal and human health. Between October 2020 September 2023, there were 36 HPAI outbreaks detected poultry other captive birds Denmark. However, it often not possible to determine the exact route introduction. We conducted case-control study compare odds exposure range potential risk factors for virus incursion into Danish or bird holdings with (cases) no (controls) during epidemiological seasons 2020/2021, 2021/2022 2022/2023. The owners 38 % eligible case 45 control declined participate, suggesting that infection sensitive subject some owners. population included 18 cases 34 controls. collected data primarily through questionnaire-based interviews estimated ratios (OR) within Bayesian framework using Beta conjugate prior define directly, Monte Carlo integration from these posterior distributions estimate relevant OR 95 credible intervals (CI) p-values. results indicated observing wild waterfowl gulls on roof around farm buildings compared none 500 m holding was higher (OR: 18.7, CI: 3.1-148, p: 0.022). This information can be used future risk-based monitoring, biosecurity management placement holdings.

Language: Английский

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