Skip to main content

Posts

Intraductal #infection with #H5N1 clade 2.3.4.4b #influenza virus

LETTER In March 2024, highly pathogenic avian influenza (HPAI) H5N1 of the clade 2.3.4.4b was detected in dairy cows in Texas and has since been detected in several other U.S. states (1). Virus has been detected within cow’s milk , indicating that the mammary epithelium may support viral replication (2). Virus has also been detected on milking machines , leading to a hypothesis that influenza is spreading through fomites from udder to udder instead of the intranasal route (3, 4). There have been studies using cows to better understand mammary infections; however, the cow model is costly and limited (1, 5). We sought to establish a model for intramammary infections of H5N1 and H1N1 influenza virus in mice . (...) Source: Journal of Virology,  https://journals.asm.org/doi/full/10.1128/jvi.01927-24?af=R _____

Monitoring for Avian #Influenza A(#H5) Virus In #Wastewater, January 19-25 2025

{Excerpt} Time Period: January 19 - January 25, 2025 -- H5 Detection : 33 sites ( 10.1% ) -- No Detection : 295 sites ( 89.9% ) -- No samples in last week : 61 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/bird-flu/h5-monitoring/index.html _____

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

The laboratory diagnosed type H5 on Thursday, January 23 in one of the sick birds that was sampled in the framework of passive surveillance , on January 24 all birds were culled, on January 29 the laboratory confirmed the detection of Neuraminidase 1 and identification of hemagglutinin genes found in the cleavage site of avian influenza virus type A lineage Goose/Guangdong (Gs/GD) subtype H5, clade 2.3.4.4. highly pathogenic. Out of the 408 backyard birds, one died and two became sick in Chiriquí Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6225 ____

#Mexico’s Laboratory-Confirmed #Human Case of #Infection with the #Influenza A(#H5N2) Virus

Abstract In April 2024, the Instituto Nacional de Enfermedades Respiratorias of Mexico City identified a case of unsubtypeable Influenza A in a 58-year-old immunocompromised patient with renal failure due to diabetic nephropathy and bacterial peritonitis. Through sequencing the M, NS, NA, NP, and HA complete segments, we identified an H5N2 influenza virus with identity of 99% with avian influenza A(H5N2) from Texcoco, Mexico, in 2024. This case is the first reported with direct evidence of human infection caused by the H5N2 influenza virus; the relationship of the virus with the severity of his condition remains unknown. Source: Viruses,  https://www.mdpi.com/1999-4915/17/2/205 _____

Suspected and confirmed #mpox cases in #DRC: a retrospective #analysis of national epidemiological and laboratory #surveillance data, 2010–23

Summary Background DR Congo has the highest global burden of mpox , a disease caused by infection with the monkeypox virus . The incidence has risen since 1980, but recent analyses of epidemiological trends are lacking. We aimed to describe trends in suspected and confirmed mpox cases in DR Congo using epidemiological and laboratory mpox surveillance data collected from 2010 to 2023, and provide insights that can better inform the targeting and monitoring of control strategies. Methods We analysed aggregated national epidemiological surveillance data and individual-level laboratory data from 2010 to 2023. We calculated incidence based on suspected cases, case-fatality ratios, and percentage of laboratory-confirmed cases and assessed geospatial trends. Demographic and seasonal trends were investigated using generalised additive mixed models. Findings Between Jan 1, 2010, and Dec 31, 2023, a total of 60 967 suspected cases and 1798 suspected deaths from mpox were reported in DR Congo ( c...

Structure of a #zoonotic #H5N1 #hemagglutinin reveals a #receptor-binding site occupied by an auto-glycan

Summary Highly pathogenic avian influenza has spilled into many mammals, most notably cows and poultry, with several dozen human breakthrough infections. Zoonotic crossovers , with hemagglutinins mutated to enhance viral ability to use human α2-6-linked sialic acid receptors versus avian α2-3-linked ones, highlight the pandemic risk . To gain insight into these crossovers, we determined the cryoelectron microscopy (cryo-EM) structure of the hemagglutinin from the zoonotic H5N1 A/Texas/37/2024 strain (clade 2.3.4.4b) in complex with a previously reported neutralizing antibody . Surprisingly, we found that the receptor-binding site of this H5N1 hemagglutinin was already occupied by an α2-3-linked sialic acid and that this glycan emanated from asparagine N169 of a neighboring protomer on hemagglutinin itself. This structure thus highlights recognition by influenza hemagglutinin of an “auto”-α2-3-linked sialic acid from N169, an N-linked glycan conserved in 95% of H5 strains, and adds “aut...

Pre-exposure #antibody #prophylaxis protects #macaques from severe #influenza

Abstract Influenza virus pandemics and seasonal epidemics have claimed countless lives. Recurrent zoonotic spillovers of influenza viruses with pandemic potential underscore the need for effective countermeasures . In this study, we show that pre-exposure prophylaxis with broadly neutralizing antibody (bnAb) MEDI8852 is highly effective in protecting cynomolgus macaques from severe disease caused by aerosolized highly pathogenic avian influenza H5N1 virus infection. Protection was antibody dose–dependent yet independent of Fc-mediated effector functions at the dose tested. Macaques receiving MEDI8852 at 10 milligrams per kilogram or higher had negligible impairment of respiratory function after infection, whereas control animals were not protected from severe disease and fatality. Given the breadth of MEDI8852 and other bnAbs, we anticipate that protection from unforeseen pandemic influenza A viruses is achievable. Source: Science,  https://www.science.org/doi/10.1126/science.ado64...

#Pasteurisation temperatures effectively inactivate #influenza A viruses in #milk

Abstract In late 2023 an H5N1 lineage of high pathogenicity avian influenza virus (HPAIV) began circulating in American dairy cattle.  Concerningly, high titres of virus were detected in cows’ milk , raising the concern that milk could be a route of human infection . Cows’ milk is typically pasteurised to render it safe for human consumption, but the effectiveness of pasteurisation on influenza viruses in milk was uncertain . To assess this, here we evaluate heat inactivation in milk for a panel of different influenza viruses. This includes human and avian influenza A viruses (IAVs), an influenza D virus that naturally infects cattle, and recombinant IAVs carrying contemporary avian or bovine H5N1 glycoproteins . At pasteurisation temperatures of 63 °C and 72 °C , we find that viral infectivity is rapidly lost and becomes undetectable before the times recommended for pasteurisation ( 30 minutes and 15 seconds, respectively ). We then show that an H5N1 HPAIV in milk is effectively i...

#WHO accelerates efforts to support response to #Sudan {hemorrhagic fever} virus disease #outbreak in #Uganda

Brazzaville/Kampala – Following the confirmation of an outbreak of Sudan virus disease – which belongs to the same family as Ebola virus disease – in Uganda today, World Health Organization (WHO) is mobilizing efforts to support the national health authorities to swiftly contain and end the outbreak .  WHO is deploying senior public health experts and mobilizing staff from the country office to support all the key outbreak response measures. In addition, the Organization has allocated US$ 1 million from its Contingency Fund for Emergencies to help accelerate early action, and is readying medical supplies, including personal protective equipment to deliver to Uganda from its Emergency Response Hub in Nairobi.  While there are no licensed vaccines for the Sudan virus disease , WHO is coordinating with developers to deploy candidate vaccines as an addition to the other public health measures. The vaccines will be deployed once all administrative and regulatory approvals are obtai...

#Perpetuation of Avian #Influenza from Molt to Fall #Migration in Wild Swan #Geese (Anser cygnoides): An Agent-Based Modeling Approach

Abstract Wild waterfowl are considered to be the reservoir of avian influenza , but their distinct annual life cycle stages and their contribution to disease dynamics are not well understood. Studies of the highly pathogenic avian influenza (HPAI) virus have primarily focused on wintering grounds, where human and poultry densities are high year-round, compared with breeding grounds, where migratory waterfowl are more isolated. Few if any studies of avian influenza have focused on the molting stage where wild waterfowl congregate in a few selected wetlands and undergo the simultaneous molt of wing and tail feathers during a vulnerable flightless period. The molting stage may be one of the most important periods for the perpetuation of the disease in waterfowl, since during this stage, immunologically naïve young birds and adults freely intermix prior to the fall migration. Our study incorporated empirical data from virological field samplings and markings of Swan Geese (Anser cygnoides)...

#NASA Shares #Observations of Recently-Identified Near Earth #Asteroid {2024 YR4}

NASA analysis of a near-Earth asteroid, designated 2024 YR4, indicates it has a more than 1% chance of impacting Earth on Dec. 22, 2032 – which also means there is about a 99% chance this asteroid will not impact. Such initial analysis will change over time as more observations are gathered .   Currently, no other known large asteroids have an impact probability above 1% .  Asteroid 2024 YR4 was first reported on Dec. 27, 2024, to the Minor Planet Center– the international clearing house for small-body positional measurements – by the NASA-funded Asteroid Terrestrial-impact Last Alert System station in Chile.  The asteroid, which is estimated to be about 130 to 300 feet wide , caught astronomers’ attention when it rose on the NASA automated Sentry risk list on Dec. 31, 2024.  The Sentry list includes any known near-Earth asteroids that have a non-zero probability of impacting Earth in the future.   An object that reaches this level is not uncommon ; there have been several obj...

The #hospital and #mortality #burden of #COVID19 compared with #influenza in #Denmark: a national observational cohort study, 2022–24

Summary Background The COVID-19 pandemic has been on a downward trend since May, 2022, but it continues to cause substantial numbers of hospital admissions and deaths . We describe this burden in the 2 years since May, 2022, and compare it with the burden of influenza in Denmark. Methods This observational cohort study included residents in Denmark from May 16, 2022, to June 7, 2024. Data were obtained from national registries, including admissions with COVID-19 or influenza (ie, having a positive PCR test for either virus from 14 days before and up to 2 days after the hospital admission date), deaths, sex, age, COVID-19 and influenza vaccination status, comorbidities , and residence in long-term care facilities. Negative binomial regression was used to estimate adjusted incidence rate ratios (aIRRs) to compare rates of hospital admissions between COVID-19 and influenza. To compare the severity of COVID-19 versus influenza among patients admitted to hospital, we used the Kaplan–Meier e...

#Zika virus disease - #India

Situation at a glance Between 1 January and 31 December 2024, a cumulative total of 151 Zika virus disease (ZVD) cases were reported from three states in India ( Gujarat, Karnataka, and Maharashtra states). Maharashtra State reported a cumulative total of 140 ZVD cases through the Integrated Disease Surveillance Programme (IDSP). Additionally, Karnataka and Gujarat states reported ten and one cases , respectively, in 2024. As of 31 December 2024, no cases of microcephaly and/or Guillain-Barre syndrome (GBS) associated with this outbreak have been reported. Zika virus (ZIKV) is transmitted to humans by the bite of an infected Aedes mosquito . Zika virus is also transmitted from mother to fetus during pregnancy, as well as through sexual contact, transfusion of blood and blood products, and possibly through organ transplantation. There is no specific treatment available for Zika virus infection or disease. Description of the situation Between 1 January and 31 December 2024, a cumulative ...

Dispersal of #influenza virus #populations within the respiratory tract shapes their evolutionary #potential

Abstract Viral infections are characterized by dispersal from an initial site to secondary locations within the host. How the resultant spatial heterogeneity shapes within-host genetic diversity and viral evolutionary pathways is poorly understood. Here, we show that virus dispersal within and between the nasal cavity and trachea maintains diversity and is therefore conducive to adaptive evolution , whereas dispersal to the lungs gives rise to population heterogeneity . We infected ferrets either intranasally or by aerosol with a barcoded influenza A/California/07/2009 (H1N1) virus . At 1, 2, or 4 days postinfection, dispersal was assessed by collecting 52 samples from throughout the respiratory tract of each animal. Irrespective of inoculation route, barcode compositions across the nasal turbinates and trachea were similar and highly diverse, revealing little constraint on the establishment of infection in the nasal cavity and descent through the trachea. Conversely, infection of the ...

#Strength and durability of indirect #protection against #SARS-CoV-2 infection through #vaccine and infection-acquired #immunity

Abstract Early investigation revealed a reduced risk of SARS-CoV-2 infection among social contacts of COVID-19 vaccinated individuals, referred to as indirect protection. However, indirect protection from SARS-CoV-2 infection-acquired immunity and its comparative strength and durability to vaccine-derived indirect protection in the current epidemiologic context of high levels of vaccination, prior infection, and novel variants are not well characterized. Here, we show that both vaccine-derived and infection-acquired immunity independently yield indirect protection to close social contacts with key differences in their strength and waning. Analyzing anonymized SARS-CoV-2 surveillance data from 9,625 residents in California state prisons from December 2021 to December 2022, we find that vaccine-derived indirect protection against Omicron SARS-CoV-2 infection is strongest within three months of COVID-19 vaccination [30% (95% confidence interval: 20–38%)] with subsequent modest protection....

A comprehensive #review of current #insights into the #virulence factors of #SARS-CoV-2

ABSTRACT The evolution of SARS-CoV-2 pathogenicity has been a major focus of attention. However, the determinants of pathogenicity are still unclear. Various hypotheses have attempted to elucidate the mechanisms underlying the evolution of viral pathogenicity , but a definitive conclusion has yet to be reached. Here, we review the potential impact of all proteins in SARS-CoV-2 on the viral pathogenic process and analyze the effects of their mutations on pathogenicity evolution. We aim to summarize which virus-encoded proteins are crucial in influencing viral pathogenicity, defined as disease severity following infection. Mutations in these key proteins, which are the virulence factors in SARS-CoV-2, may be the driving forces behind the evolution of viral pathogenicity. Mutations in the S protein can impact viral entry and fusogenicity . Mutations in proteins such as NSP2, NSP5, NSP14, and ORF7a can alter the virus’s ability to suppress host protein synthesis and innate immunity . Mutat...