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#Measles – Region of the #Americas (#WHO D.O.N., April 28 '25)

{Excerpt} Situation at a glance As of 18 April 2025, a total of 2318 measles cases , including three deaths , have been confirmed in six countries in the WHO Region of the Americas , an 11-fold increase compared to the same period in 2024 .  The majority of cases have occurred among people between 1 to 29 years , who are either unvaccinated or have an unknown vaccination status .  Additionally, most cases are imported or linked to importation.  Measles is a highly contagious, airborne viral disease that can lead to severe complications and death.  Although it is preventable with two doses of the vaccine, over 22 million children worldwide did not receive their first dose of the vaccine in 2023. This has contributed to a global rise in measles cases in 2024, which heightens the risk of imported infections, particularly from unvaccinated travellers arriving from areas where the virus is actively circulating.  WHO is working closely with countries in the WHO Region...

Circulation and #Spillover of #H1N1pdm09 #Influenza A Virus at an Educational #Swine #Farm in #Chile, 2019–2023

Abstract Educational farms provide students with hands-on experience in agricultural and animal practices . However, the close contact between humans and farm animals creates a significant interface for zoonotic disease transmission , yet research on infectious diseases in such settings remains limited. This study investigates the ongoing spillovers of human-origin influenza A virus (IAV) into swine at an educational farm in central Chile , describing IAV prevalence, outbreak dynamics, and the genomic characterization of detected strains. The Menesianos educational farm, located in Melipilla, central Chile, houses approximately 40 swine alongside other domestic animals , such as horses and cows . As part of an active IAV surveillance project, monthly nasal swab samples were collected from pigs between June 2019 and September 2023 for IAV detection via RT-qPCR targeting the M gene, with positive samples subsequently sequenced. During the study period, monthly IAV prevalence ranged from ...

#Risk of Highly Pathogenic Avian #Influenza A #H5N1 Virus in #Pediatrics

Abstract Highly Pathogenic Avian Influenza A/H5N1 Virus has been found in multiple US states since 2024. While human infection risk is currently low, children are a high-risk group for severe infection as the virus evolves. Preventive efforts should prioritize children in vaccine and therapeutic clinical trials and vaccine implementation strategies. Source: Journal of Pediatric Infectious Diseases Society,  https://academic.oup.com/jpids/advance-article-abstract/doi/10.1093/jpids/piaf035/8120791?redirectedFrom=fulltext ____

Improving #Influenza #Nomenclature Based on #Transmission Dynamics

Abstract Influenza A viruses (IAVs) evolve rapidly, exhibit zoonotic potential , and frequently adapt to new hosts , often establishing long-term reservoirs. Despite advancements in genetic sequencing and phylogenetic classification , current influenza nomenclature systems remain static, failing to capture evolving epidemiological patterns . This rigidity has led to delays or misinterpretations in public health responses , economic disruptions, and confusion in scientific communication. The existing nomenclature does not adequately reflect real-time transmission dynamics or host adaptations, limiting its usefulness for public health management. The 2009 H1N1 pandemic exemplified these limitations, as it was mischaracterized as “swine flu” despite sustained human-to-human transmission and no direct pig-to-human transmission reported. This review proposes a real-time, transmission-informed nomenclature system that prioritizes host adaptation and sustained transmissibility (R0 > 1) to ...

Exploring Avian #Influenza Viruses in #Yakutia—The Largest #Breeding #Habitat of Wild Migratory #Birds in Northeastern #Siberia

Abstract Yakutia, the largest breeding ground for wild migratory birds in Northeastern Siberia , plays a big role in the global ecology of avian influenza viruses (AIVs). In this study, we present the results of virological surveillance conducted between 2018 and 2023, analyzing 1970 cloacal swab samples collected from 56 bird species . We identified 74 AIVs of H3N6, H3N8, H4N6, H5N3, H7N7, H10N3, and H11N9 subtypes in Anseriformes order. Phylogenetic analysis showed that the isolates belong to the Eurasian lineage and have genetic similarities with strains from East Asia, Europe, and North America. Cluster analysis has demonstrated the circulation of stable AIV genotypes for several years. We assume that Yakutia is an important territory for viral exchange on the migratory routes of migrating birds. In addition, several amino acid substitutions have been found to be associated with increased virulence and adaptation to mammalian hosts , highlighting the potential risk of interspecific...

#Sudan virus disease - #Uganda (#WHO D.O.N., April 26 '25)

{Summary} Situation at a glance On 26 April 2025, the Ministry of Health (MoH) of Uganda declared the end of the Sudan virus disease (SVD) outbreak after two consecutive incubation periods (a total of 42 days) since the last person confirmed with SVD tested negative for the virus on 14 March 2025.  A total of 14 SVD cases (including 12 confirmed cases and two probable cases) including four deaths (two confirmed and two probable) have been reported during this outbreak.  WHO and partners provided technical , operational and financial support to the government to contain the outbreak.  Although the outbreak has been declared over , health authorities are maintaining surveillance to rapidly identify and respond to any re-emergence.  Risk communication and community engagement will also continue to ensure the community stay informed and stigma to those who were affected is minimized. (...) Source: World Health Organization,  https://www.who.int/emergencies/disease-o...

#Influenza virus #infection in the #lungs leads to #pancytopenia and defective immune cell differentiation program in the #thymus and bone marrow

Abstract Exaggerated inflammation and cytokine storm are hallmark features of influenza A virus (IAV)-induced respiratory diseases. While previous studies unequivocally demonstrated the pathophysiological consequences (multiorgan failure) of IAV-associated cytokine storm, it remains unknown if IAV-induced systemic inflammation impacts the fitness and differentiation of immune cells from hematopoietic stem cells (HSCs). Our data on lethal IAV-infected C57BL/6 wildtype mice after 10 days of infection indicated reduced monocyte- and lymphocyte- counts in the peripheral blood, and overall cellularity of spleen, thymus and lymph nodes . IAV- infection resulted in increased numbers of myeloid cells, CD8+ T cells, alveolar macrophages (AVMs), CD11b+ dendritic cells (DCs) & plasmacytoid DCs (pDCs), whereas decreased frequencies of CD103+ DCs, in the lungs of IAV-infected mice. Analysis of spleen and draining lymph nodes indicated reduced absolute numbers of B cells, T cells, monocytes and ...

#Coronavirus Disease Research #References (by AMEDEO, April 26 '25)

  Am J Obstet Gynecol THEL H, Latour CD, Tsevat D, Dissanayake M, et al Prevalence of male and female permanent contraception and long-acting reversible contraceptives among commercially insured US population, 2010-2022. Am J Obstet Gynecol. 2025 Apr 18:S0002-9378(25)00230. PubMed          KEULS RA, Ochsner SA, O'Neill MB, O'Day DR, et al Single-nucleus transcriptional profiling of the placenta reveals the syncytiotrophoblast stress response to COVID-19. Am J Obstet Gynecol. 2025;232. PubMed           Abstract available Int J Infect Dis BERENDS MS, Homburg M, Kupers T, Meijer EN, et al Impact of Pre-Existing Comorbidities and Multimorbidities, Demography and Viral Variants on Post-Acute Sequelae of COVID-19 ('Long COVID') in Dutch Primary Care: A Retrospective Cohort Study. Int J Infect Dis. 2025 Apr 19:107912. doi: 10.1016/j.ijid.2025.107912. PubMed           Abstract...

#Influenza and Other Respiratory Viruses Research #References (by AMEDEO, April 26 '25)

  Antiviral Res ZHU Y, Gao Z, Feng X, Hu Y, et al Comprehensive preclinical characterization of IPB29, a pan-coronavirus fusion inhibitor under clinical trials. Antiviral Res. 2025;237:106154. PubMed           Abstract available BONNEUX B, Ceconi M, Stobbelaar K, Herschke F, et al Insights in the RSV L polymerase function and structure. Antiviral Res. 2025;237:106148. PubMed           Abstract available BRUN J, Arman BY, Hill ML, Kiappes JL, et al Assessment of repurposed compounds against coronaviruses highlights the antiviral broad-spectrum activity of host-targeting iminosugars and confirms the activity of potent directly acting antivirals. Antiviral Res. 2025 Feb 23:106123. doi: 10.1016/j.antiviral.2025.106123. PubMed           Abstract available ZIAN D, Iaconis D, Nenci S, Crusco A, et al The Efficiency of High-Throughput Screening (HTS) and in-silico data an...

#Biosecurity uptake and perceived #risk of avian #influenza among people in #contact with #birds in the #UK

Abstract Recent intercontinental spread of highly pathogenic avian influenza (HPAI) A(H5N1) among kept and wild birds and transmission to mammalian hosts , including cattle and humans has heightened the need to review public health risk assessments . Biosecurity is essential for limiting disease spread, but how widely practices are implemented is not fully known. Here, we report on the uptake of biosecurity measures using questionnaire data collected in 2024 from people in contact with birds in the UK (Avian Contact Study). Almost half of the sample were poultry farmers (104/225). We found hand washing after contact with birds was the most common biosecurity measure implemented (89%, 196/218), followed by using disinfecting footwear dips (78%, 170/218). Individuals in contact with a higher number of birds were more likely to use at least one PPE measure for the face or body (χ^2 (1, n=217) = 32.452, p<0.001) or at least one footwear-related PPE measure (Df=1, n=217, p<0.001), ind...

The expanding avian #influenza #panzootic: #skua die-off in #Antarctica

Abstract High pathogenicity avian influenza virus of subtype H5 (H5 HPAIV), clade 2.3.4.4b, invaded Antarctica in 2023 . Here we show that H5 HPAIV caused high mortality in a breeding colony of skuas at one of ten sites we visited in March 2024. By combined virological and pathological analyses, we found that H5 HPAIV caused multi-organ necrosis and rapid death in skuas . Taken together with recent data, skuas in Antarctica are at risk of continued mortality from H5 HPAIV infection, threatening their already small populations . Conversely, because of their wide distribution and ecological relevance, skuas may play a substantial role in the spread of the virus across Antarctica. Transdisciplinary surveillance is needed in coming years to monitor the impact of this poultry-origin disease on Antarctica's unique wildlife. Source: BioRxIV,  https://www.biorxiv.org/content/10.1101/2025.04.25.650384v1 ____

The #bat #influenza A virus subtype #H18N11 induces nanoscale MHCII clustering upon host #cell attachment

Abstract Prior to the discovery of bat influenza A virus (IAV) subtypes H17N10 and H18N11 , all IAVs were thought to bind sialic acid residues via hemagglutinin (HA) to mediate attachment and subsequent viral entry. However, H17 and H18 engage a proteinaceous receptor : the major histocompatibility complex class II (MHCII). The mechanistic details of this hitherto unknown protein-mediated entry are not understood. Given that conventional IAVs rely on multivalent binding to sialylated glycans , we hypothesized that bat HA similarly interacts with multiple MHCII molecules. Using photoactivated localization microscopy (PALM) on fixed and live cells, we demonstrate that bat IAV particles attach to pre-existing MHCII clusters and induce a further increase in cluster size upon binding. To measure the impact of viral attachment on the dynamics of MHCII, we employ an “inverse attachment” approach, immobilizing viral particles on coverslips before seeding live MHCII-expressing cells on top. Sin...

Single #influenza A viruses induce #nanoscale cellular #reprogramming at the virus-cell interface

Abstract During infection, individual virions trigger specific cellular signaling at the virus-cell interface , a nanoscale region of the plasma membrane in direct contact with the virus. However, virus-induced receptor recruitment and cellular activation are transient processes that occur within minutes at the nanoscale. Hence, the temporal and spatial kinetics of such early events often remain poorly understood due to technical limitations. To address this challenge, we develop a protocol to covalently immobilize labelled influenza A viruses on glass surfaces before exposing them to live epithelial cells . Our method extends the observation time for virus-plasma membrane association while minimizing viral modifications, facilitating live imaging of virus-cell interactions . Using single-molecule super-resolution microscopy, we investigate virus-receptor interaction showing that viral receptors exhibit reduced mobility at the virus-binding site, which leads to a specific local recepto...

A modelling #assessment for the #impact of #control measures on highly pathogenic avian #influenza #transmission in #poultry in Great #Britain

Abstract Since 2020, large-scale outbreaks of highly pathogenic avian influenza (HPAI) H5N1 in Great Britain have resulted in substantial poultry mortality and economic losses. Alongside the costs, the risk of circulation leading to a viral reassortment that causes zoonotic spillover raises additional concerns. However, the precise mechanisms driving transmission between poultry premises and the impact of potential control measures in Great Britain, such as vaccination, are not fully understood. We have developed a spatial transmission model for the spread of HPAI in poultry premises calibrated to infected premises data for the 2022--23 season using Markov chain Monte Carlo . Our results indicate that enhanced biosecurity measures and/or vaccination of the premises surrounding an identified infected premises can substantially reduce the overall number of infected premises. Our findings highlight that enhanced control measures could limit the future impact of HPAI on the poultry industr...

#USA, Monitoring for Avian #Influenza A(#H5) Virus In #Wastewater {as of April 25 '25}

{Excerpt} Time Period: April 13, 2025 - April 19, 2025 -- H5 Detection :  4 sites ( 1.0% ) -- No Detection :  406 sites ( 99.0% ) -- No samples in last week :  153 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/bird-flu/h5-monitoring/index.html?cove-tab=0 ____

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

A poultry farm in Quang Tri province. Source: WOAH,  https://wahis.woah.org/#/in-review/6440 ____

The #receptor binding properties of #H5Nx #influenza A viruses have evolved to promiscuously bind to avian-type mucin-like O-glycans

Abstract Highly pathogenic H5Nx influenza A viruses are causing unprecedented, season-independent outbreaks across avian and mammalian species, including dairy cattle, a novel reservoir. The sialoside-binding properties of influenza A hemagglutinin (HA) are strongly related to its ability to infect and transmit between hosts. Mucin-like O-glycans , omnipresent in respiratory tracts, have been understudied as viral receptors due to their complexity. To address this, we synthesized 25 O-linked glycans with diverse sialosides, including modifications by fucosides and sulfates. Our findings reveal that H5Nx 2.3.4.4b viruses uniquely bind core 3 sialyl-Lewisx and Sia-Gal-β3GalNAc, glycans not recognized by classical H5 or other avian viruses. By determining its crystal structure, we resolved the structural features of both structures in an H5 hemagglutinin (HA) from a 2016 2.3.4.4b virus. While these viruses do not bind human-type receptors , their promiscuous receptor specificity enhances ...

Emergence and interstate spread of highly pathogenic avian #influenza A(#H5N1) in dairy #cattle in #USA

Editor’s summary High-pathogenicity avian influenza subtype H5N1 is now present throughout the US , and possibly beyond. More cattle infections elevate the risk of the virus evolving the capacity to transmit between humans , potentially with high fatality rates . Nguyen et al. show that from a single transmission event from a wild bird to dairy cattle in December 2023, there has been cattle-to-poultry, cattle-to-peridomestic bird , and cattle-to-other mammal transmission. The movement of asymptomatic dairy cattle has facilitated the rapid dissemination of H5N1 from Texas across the US . Evolution within cattle, assessed using deep-sequencing data, has detected low-frequency sequence variants that had previously been associated with mammalian adaptation and transmission efficiency. —Caroline Ash Structured Abstract INTRODUCTION Highly pathogenic avian influenza (HPAI) viruses have critical consequences for animal health and the agricultural economy—and may have pandemic potential. HPAI ...

#Seroprevalence of #H9N2 and #H5 avian #influenza in mixed-species #poultry #farms in Northern #Benin

ABSTRACT Avian influenza is one of the major threats to poultry and human health in northern Benin , while mixed-species farming systems increase the risks of viral transmission. The present study estimated the seroprevalence of avian influenza subtypes H9N2 and H5 in indigenous chickens and guinea fowls in the Atacora and Donga regions. A total of 300 birds including 191 indigenous chickens and 109 guinea fowls, from six districts were sampled through a cross-sectional survey using systematic random sampling. Hemagglutination inhibition assay was used to detect antibodies, revealing an overall H9N2 seroprevalence of 41%, with 17.5% of samples testing positive for H5 . The seroprevalence of H9N2 was notably higher in guinea fowls (51.81% in Atacora and 52% in Donga) compared to chickens (34.95% in Atacora and 34.83% in Donga). H5 antibodies were found only in guinea fowls in Atacora (46.66%). The study also found that farms with both chickens and guinea fowls had a significantly higher...