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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 ...

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...

Abstract In 2018, a clinical trial of four investigational therapies for Ebola virus disease (EVD), known as the PALM trial , was conducted in the Democratic Republic of Congo . All patients received either the antiviral remdesivir (RDV) or a monoclonal antibody product : ZMapp, mAb114 (Ebanga), or REGN-EB3 (Inmazeb). The study concluded that both mAb114 and REGN-EB3 were superior to ZMapp and RDV in reducing mortality from EVD. However, the data suggested that some patients in the RDV and ZMapp groups might have been sicker at the time of treatment initiation. Here, we assessed the efficacy of each of these therapies in a uniformly lethal rhesus monkey model of EVD when treatment was initiated 5 days after Ebola exposure. Treatment with RDV, mAb114, REGN-EB3, and ZMapp each resulted in similar survival (approximately 40% ). Survival was associated with circulating viral load at treatment initiation. A trend of more escape mutants in the GP1 and GP2 domains was observed for the mAb114 ...

Abstract H5Nx clade 2.3.4.4b high-pathogenicity avian influenza viruses (HPAIVs) have decimated wild bird and poultry populations globally since the autumn of 2020. In the United Kingdom (UK) and in continental Europe , the H5N8 subtype predominated during the first epizootic wave of 2020/21, with few detections of H5N1 . However, during the second (2021/22) and third (2022/23) epizootic waves , H5N1 was the dominant subtype. The rapid shift in dominance from H5N8 to H5N1 was likely driven by a combination of virological, immunological, and/or host-related factors . In this study, we compared viral fitness and immunological responses in ducks , a key reservoir species, using dominant genotypes of H5N1 (genotype AB) and H5N8 (genotype A) from the second wave. While viral shedding dynamics were similar for both viruses, H5N8 was more pathogenic . Antigenic analysis of post-infection duck sera revealed that the haemagglutinin (HA) protein was antigenically similar across clade 2.3.4.4b H5...

Abstract Background Baloxavir marboxil (baloxavir) rapidly reduces influenza virus shedding , which suggests that it may reduce transmission. Studies of treatment with neuraminidase inhibitors have not shown sufficient evidence that they prevent transmission to contacts. Methods We conducted a multicountry, phase 3b trial to assess the efficacy of single-dose baloxavir treatment to reduce influenza transmission from index patients to household contacts. Influenza-positive index patients 5 to 64 years of age were randomly assigned in a 1:1 ratio to receive baloxavir or placebo within 48 hours after symptom onset. The primary end point was transmission of influenza virus from an index patient to a household contact by day 5. The first secondary end point was transmission of influenza virus by day 5 that resulted in symptoms. Results Overall, 1457 index patients and 2681 household contacts were enrolled across the 2019–2024 influenza seasons; 726 index patients were assigned to the baloxa...

Abstract Colorectal cancer incidence rates vary geographically and have changed over time1 . Notably, in the past two decades, the incidence of early-onset colorectal cancer , affecting individuals under the age of 50 years, has doubled in many countries2-5. The reasons for this increase are unknown . Here, we investigate whether mutational processes contribute to geographic and age-related differences by examining 981 colorectal cancer genomes from 11 countries . No major differences were found in microsatellite unstable cancers, but variations in mutation burden and signatures were observed in the 802 microsatellite-stable cases. Multiple signatures, most with unknown etiologies , exhibited varying prevalence in Argentina, Brazil, Colombia, Russia , and Thailand , indicating geographically diverse levels of mutagenic exposure. Signatures SBS88 and ID18, caused by the bacteria-produced mutagen colibactin 6,7, had higher mutation loads in countries with higher colorectal cancer inciden...

{Excerpt} The Centre for Health Protection (CHP) of the Department of Health today (April 23) received a report of a case of severe paediatric COVID-19 and human metapneumovirus (hMPV) infection and reminded the public to observe personal, hand and environmental hygiene at all times. High-risk individuals should receive a COVID-19 vaccination as soon as possible and receive booster doses at appropriate times to minimise the risk of serious complications and death after infection. The case involves an eight-month-old girl with good past health, who developed a fever and runny nose since April 19 and sought medical attention from a private doctor the next day. She developed cough and shortness of breath on April 21 and sought medical attention from another private doctor. She attended the Accident and Emergency Department of Hong Kong Adventist Hospital – Tsuen Wan on April 22 and was transferred to the Paediatric Intensive Care Unit of Princess Margaret Hospital for treatment on the sam...

Abstract The ecological factors that led to the 1918 influenza pandemic remain unknown. We hypothesise that horses acted as intermediate hosts spreading a pre-pandemic avian-origin virus before 1918. This is supported by reports describing a large epizootic of unusually severe equine influenza beginning in 1915. Furthermore, the high horse demand during WWI resulted in one of the biggest equine mobilisations in North America between 1914 and 1918. This extensive movement of horses provided abundant opportunities for virus reassortment between pre-pandemic avian and human influenza viruses. Archived equine tissues or serum samples will be needed to test this hypothesis. Source: Journal of Infectious Diseases,  https://academic.oup.com/jid/advance-article-abstract/doi/10.1093/infdis/jiaf197/8115353?redirectedFrom=fulltext&login=false ____

ABSTRACT The highly pathogenic avian influenza virus A(H5N1) clade 2.3.4.4b has caused a human outbreak in North America since March 2024. Here, we conducted a serosurveillance study to determine the risk of A(H5N1) clade 2.3.4.4b (2024 cattle H5N1) to general population. In the initial screening of 180 serum specimens encompassing all age groups, 2.2% (4/180) had detectable neutralizing antibody (nAb) titers against reverse genetics-derived 2024 cattle H5N1, with all collected from older adults aged ≥60 years old. Further screening showed that 4.2% (19/450) of adults aged ≥60 years old had detectable nAb titers against the 2024 cattle H5N1 . 80% (4/5) serum specimens with nAb titer of ≥40 had detectable HI titer, and there was a positive correlation between nAb titer and HA binding (r = 0.3325, 95% confidence interval 0.2477 to 0.4123; P < 0.0001). The nAb titer against seasonal H1N1 virus was 4.2-fold higher for ≥60 years old individuals with detectable H5N1 nAb titer than those ≥...

Abstract We detected influenza D virus in multiple swine herds in Northern Ireland . Whole-genome sequencing showed several circulating genotypes and novel mutations in the receptor-binding site and esterase domains of the hemagglutinin-esterase fusion protein. Transmission routes of influenza D virus to swine remain to be clarified but could be direct or indirect. Source: US Centers for Disease Control and Prevention,  https://wwwnc.cdc.gov/eid/article/31/5/24-1948_article ____

Abstract Several concurrent mpox outbreaks are ongoing in the Democratic Republic of the Congo . We report a case of severe clade Ia mpox in an adult woman with indeterminate HIV status who died 16 days after symptom onset. She self-identified as a sex worker and had spent time in the capital city, Kinshasa. Source: US Centers for Disease Control and Prevention,  https://wwwnc.cdc.gov/eid/article/31/5/24-1690_article ____

Abstract The introduction and subsequent detection of highly pathogenic avian influenza (HPAI) in poultry is influenced by the virus replication fitness, transmission fitness, and virulence in poultry. These viral fitness parameters are important for implementing surveillance and control measures for poultry. This study investigates the potential application of an avian in vitro model using primary chicken embryo (CEF) and duck embryo fibroblasts (DEF) to identify the viral fitness for a reference panel of eight dominant HPAI clade 2.3.4.4 virus genotypes : four H5N1 viruses isolated between 2021 and 2024, as well as three H5N8 and one H5N6 virus isolated between 2014 and 2020. Infectious virus titre and cytopathogenicity were measured in the primary cell cultures over time and these data were analysed using a mathematical model which delineates cell populations into susceptible, latent, infectious, and dead compartments. In addition to obtaining traditional virological parameters such...

Abstract We performed serologic surveillance for selected arthropod-borne viruses (arboviruses) in bats and opossums in the Lacandona Rainforest, Chiapas, Mexico , in 2023–2024. Sera were collected from 94 bats of at least 15 species and 43 opossums of three species. The sera were assayed by the plaque reduction neutralization test (PRNT) for antibodies to eight orthoflaviviruses ( dengue viruses 1–4, St. Louis encephalitis virus , T’Ho virus, West Nile virus, and Zika virus ) and one alphavirus (chikungunya virus; CHIKV). Twelve (12.8%) bats and 15 (34.9%) opossums contained orthoflavivirus-specific antibodies . One bat (a Jamaican fruit bat) was seropositive for Zika virus , and 11 bats contained antibodies to an undetermined orthoflavivirus , as did the 15 opossums. All bats and most opossums seropositive for an undetermined orthoflavivirus had low PRNT titers, possibly because they had been infected with another (perhaps unrecognized) orthoflavivirus not included in the PRNTs. Anti...

Abstract Lassa mammarenavirus (LASV), a member of the family Arenaviridae , is a highly pathogenic virus capable of causing severe systemic infections in humans . The primary host reservoir is the Natal multimammate mouse (Mastomys natalensis), with human infections typically occurring through mucosal exposure to virus-containing aerosols from rodent excretions . To better understand the molecular mechanisms underlying LASV replication in the respiratory tract, we utilized differentiated primary human airway epithelial cells (HAECs) grown under air–liquid interface conditions, closely mimicking the bronchial epithelium in vivo. Our findings demonstrate that HAECs are permissive to LASV infection and support productive virus replication . While LASV entry into polarized HAECs occurred through both apical and basolateral surfaces , progeny virus particles were predominantly released from the apical surface , consistent with an intrinsic apical localization of the envelope glycoprotein GP...

Influenza A H5N1, New Cases reported, week 16/2025 : - Date: 18/04/2025; - Country: Vietnam;  - Province: Tay Ninh province, Ben Cau district;  - Sex: Female; - Age: 8;  - Clinical condition: Serious; - Subtype: H5N1. (...) Source: Centre for Health Protection, Hong Kong PRC SAR,  https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk16.pdf ____

Abstract The avian influenza virus (AIV) primarily affects birds and poses an increasing concern due to its growing adaptability to other hosts , heightening zoonotic risks . The adaptability is a key factor in AIV to infect multiple non-avian species, including humans , companion animals , aquatic mammals , carnivores , and other mammals. The virus is evolving through genetic mutations and reassortments , leading to the emergence of AIV strains with enhanced virulence and adaptability in mammals. This highlights the critical need to understand the genetic factors of AIV, including mutations in polymerase proteins , surface antigens , and other regulatory proteins, as well as the dynamics of AIV- host interactions and environmental factors such as temperature, humidity, water salinity, and pH that govern the cross-species adaptability of the virus. This review provides comprehensive insights into the molecular/genetic changes AIV undergoes to adapt in mammalian hosts including bovines,...

Abstract The spread of the highly pathogenic avian influenza (HPAI) H5N1 virus among dairy cattle illustrates the adaptability of influenza A viruses (IAV) to infect non-traditional species . While IAV-specific sialic acid (SA) receptors have been identified in the mammary glands of dairy cattle , their presence in pigs, sheep, goats, and alpacas has not been studied until now. The zoonotic transmission of HPAI H5N1 to dairy and poultry farm workers during outbreaks raises public health concerns . This study employed lectin histochemistry to examine the mammary glands of livestock and humans . We found that these tissues were rich in SA α2,6-Gal receptors, followed by SA α2,3-Gal receptors , essential for IAV binding . Notably, the A(H5N1) clade 2.3.4.4b virus could bind to mammary tissue from both cattle and pigs . These findings highlight the potential for HPAI H5N1 to infect and spread within the mammary glands of production animals and humans. Source: BioRxIV,  https://www.bior...

Abstract Influenza A virus poses significant public health challenges , causing seasonal outbreaks and pandemics. Its rapid evolution motivates continuous monitoring of circulating influenza genomes to inform vaccine and antiviral development. Wastewater-based surveillance offers an unbiased, cost-effective approach for genomic surveillance. We developed a novel tiling amplicon primer panel that covers diversity of influenza A virus, targeting segments of the surface proteins HA, NA, and M of subtypes H1N1 and H3N2. Using this panel, we sequenced nucleic acid extracts from 59 Swiss wastewater samples collected at four locations during the 2022/2023 and 2023/2024 winter seasons. We found that wastewater-based abundance estimates of the dominant H1N1 clades correlated with clinical-based estimates in the 2023/2024 season. Furthermore, wastewater-based sequencing revealed mutations in vaccine and drug target sites , consistent with clinical data. Overall, we demonstrate the effectiveness ...

Abstract High pathogenicity avian influenza (HPAI) H5N1 2.3.4.4b poses a substantial conservation threat to ecosystems , populations, and species globally, with its continued spread into new regions increasing concern for potential ecological consequences . During surveys in February-March 2025, we confirmed the virus presence at the southern extent of its known range along the Western Antarctic Peninsula, with recorded mortalities in South Polar Skuas Stercorarius maccormicki on distinct islands in Marguerite Bay , as well as one confirmed and one suspected case in Kelp Gulls Larus dominicanus . At the time of sampling, no evidence of infection was observed in other seabird or mammal species. Consistent with previous global reports, skuas - here, South Polar Skuas - appear particularly vulnerable, yet broader impacts on the local seabird and mammal community remain unclear. Additionally, our use of rapid antigen tests (VDRG AIV Ag Rapid kit 2.0 Median Diagnostics) in the field demonst...

Highlights •  A large B19V French outbreak of an unexpected magnitude occurred, with a monthly rate that has reached 21.4%. •  During this outbreak, 50% of infected pregnant women exhibited fetal complications. •  Phylogenetic analysis revealed the co-circulation of several B19V lineages of genotype 1a, the main epidemic lineage of which emerged in 2017. Abstract Background The human parvovirus B19 (B19V) infections cycle occurs in 3- to 4-year periods and is responsible for benign childhood erythema infectiosum . It is also associated with transient aplastic crisis in patients with underlying hemolytic diseases and with severe fetal sometimes fatal infection . This study investigated the epidemiological, clinical and molecular characteristics of an unusually large 2023-2024 outbreak of B19V. Methods . Laboratory-confirmed cases were retrospectively and prospectively recorded at the Clermont-Ferrand University Hospital, France , between January, 2018 and November, 2023 an...