ETIDIOH - NEW

Abstract The recent spillover events of highly pathogenic avian influenza (HPAI) A(H5N1) clade 2.3.4.4b to dairy cattle , and high viral shedding in the milk from infected animals, has created concern that milk and dairy products could be a route for human infection . It has been demonstrated that pasteurization is effective in inactivating A(H5N1) in milk. However, multiple dairy products are made with unpasteurized but thermised milk . The aim of this study was to examine whether some conditions commonly used for thermisation are effective against inactivation of A(H5N1) in whole milk. For this purpose, we artificially inoculated whole raw cow milk with 6.5 log10 EID50 A(H5N1) and heated for 15 seconds at 60°C, 63°C and 66°C , the viral infectivity was tested using embryonated chicken eggs. We observed over 4 and 5 log10 reduction in viral infectivity at 60°C and 63°C, respectively. The viral infectivity was reduced to below the detection limit at 66°C. We also calculated the D-value...

Abstract Highly pathogenic H5N1 avian influenza viruses (HPAIV) belonging to lineage 2.3.4.4b emerged in Chile in December 2022, leading to mass mortality events in wild birds, poultry, and marine mammals and one human case . We detected HPAIV in 7,33% (714/9745) of cases between December 2022–April 2023 and sequenced 177 H5N1 virus genomes from poultry, marine mammals, a human, and wild birds spanning >3800 km of Chilean coastline . Chilean viruses were closely related to Peru’s H5N1 outbreak, consistent with north-to-south spread down the Pacific coastline . One human virus and nine marine mammal viruses in Chile had the rare PB2 D701N mammalian-adaptation mutation and clustered phylogenetically despite being sampled 5 weeks and hundreds of kilometers apart . These viruses shared additional genetic signatures , including another mammalian PB2 adaptation (Q591K, n = 6), synonymous mutations, and minor variants. Several mutations were detected months later in sealions in the Atlanti...

ABSTRACT The evolution of the antibody response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is impacted by the nature and number of antigenic exposures . First-generation coronavirus disease 2019 (COVID-19) vaccines encoded an ancestral spike protein . Updated bivalent vaccines and breakthrough infections have shaped the intricate diversity of the polyclonal antibody response and specificity of individual antibody clones. We and others previously showed that bivalent vaccines containing the ancestral and Omicron (BA.5) spikes induce high levels of cross-reactive antibodies but undetectable BA.5-specific antibodies in serum. Here, we assessed sera collected before as well as 1 and 3 months following administration of an updated XBB.1.5 monovalent vaccine to individuals with diverse infection and vaccination histories. Vaccination increased neutralization against recent variants of concern , including HV.1, JN.1 , and the vaccine-homologous XBB.1.5. Antibody bindi...

ABSTRACT The highly pathogenic avian influenza virus (HPAIV) A(H5N1) has caused the most extensive and severe epizootic event affecting both poultry and wild birds globally. This study investigated the impact of HPAIV on the breeding population of the Black-headed Gull Chroicocephalus ridibundus , the most abundant gull species in Poland . During the 2023 outbreak, this species was reported as the most frequently infected in the country. A higher-than-natural adult mortality rate (greater than 1.5% of the breeding individuals) was observed in 114 surveyed colonies across all regions of Poland. Laboratory tests confirmed the presence of HPAIV in all 17 colonies sampled, with average adult mortality estimated at 26.1%, and ranging from 1.7% to 77.8%. The estimated mortality rate across all surveyed colonies was 22.2%. Extrapolations across the entire Polish breeding population (at least 115,000 pairs according to the national census) indicated that approximately 51,000 adult Black-headed...

Abstract Objectives This study aims to provide real-time surveillance of epidemiological outbreaks of avian influenza in humans and mammals . The primary objective is to understand and track the dynamics of outbreaks as they develop, facilitating timely interventions and informed public health decisions. The data collection is part of a broader initiative focused on improving preparedness and response capabilities to emerging health threats . Data description The dataset includes comprehensive and up-to-date information on epidemiological patterns, including geographic spread, incidence rates, and demographic factors. Collected through systematic monitoring and reporting systems, this dataset is invaluable to researchers seeking to understand the evolving nature of avian influenza outbreaks in the global context. By sharing these data, we aim to contribute to the collective knowledge base by supporting evidence-based strategies for effective public health management and intervention. S...

Abstract Ferrets are widely used to model airborne transmission of influenza viruses in humans. Airborne transmission is evaluated by infecting donor ferrets with a high virus dose (106 infectious units) and monitoring transmission to contact animals sharing the same airspace . However, humans can be infected with a broad range of influenza virus doses. Therefore, we evaluated the relationship between virus inoculation dose and transmission for two pandemic influenza viruses in ferrets. Donor ferrets were inoculated with 100 to 106 tissue culture infectious dose 50 (TCID50) of the 2009 pandemic H1N1 or 1968 H3N2 pandemic virus , and were then paired with respiratory contacts . Using the proportion of donors that became infected across virus doses, we calculated the infectious dose 50 (ID50). Subsequently, by comparing the proportion of respiratory contacts that became infected, we calculated the transmissible dose 50% (TD50): the donor inoculation dose that resulted in transmission to ...

Abstract Since the first emergence of highly pathogenic avian influenza (HPAI) H5N1 viruses in dairy cattle , the virus has continued to spread, reaching at least 16 states and at least 950 dairy herds in the United States . Subsequently, spillovers of the virus from dairy cattle to humans have been reported. Pigs are an important reservoir in influenza ecology because they serve as a mixing vessel in which novel reassortant viruses with pandemic potential can be generated. Here, we show that oro-respiratory infection of pigs resulted in productive replication of a bovine-derived HPAI H5N1 B3.13 virus. Infectious viruses were mainly identified in the lower respiratory tract of principal infected pigs, and sero-conversion was observed in most of the principal pigs at later time points. In one animal, we detected the emergence of a mutation in hemagglutinin (HA) previously associated with increased affinity for mammalian-type alpha 2,6-linked sialic acid receptors , but this mutation did...

Abstract Acute Hemorrhagic Conjunctivitis (AHC) is primarily caused by viral infections, with Coxsackievirus A-24v (CV-A24v) being a significant culprit. Enteroviruses , including CV-A24v, are responsible for global AHC outbreaks . Over time, CV-A24v has evolved, and genotype IV (GIV) has become the dominant strain. This study focused on examining the genetic features and evolutionary trends of CV-A24v responsible for the recent AHC outbreak of 2023 in India . Researchers isolated viral strains from ocular swabs and confirmed the presence of CV-A24v using reverse transcriptase quantitative PCR (RT-qPCR) and whole-genome sequencing . Genomic comparisons between isolates of 2023 and those from a previous outbreak in 2009 were conducted. Phylogenetic analysis revealed that the 2023 isolates formed a distinct cluster within GIV-5 and were related to recent strains from China and Pakistan . The older Indian isolates from 2009 grouped with GIV-3. New subclades, GIV-6 and GIV-7, were also ide...

 A poultry farm in Durrës Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6305 ____

ABSTRACT The COVID-19 pandemic has greatly enhanced our understanding of CD8+ T cell immunity and their role in natural infection and vaccine-induced protection. Rapid and early SARS-CoV-2- specific CD8+ T cell responses have been associated with efficient viral clearance and mild disease . Virus-specific CD8+ T cell responses can compensate for waning, morbidity-related , and iatrogenic reduction of humoral immunity. After infection or vaccination, SARS-CoV-2-specific memory CD8+ T cells are formed, which mount an efficient recall response in the event of breakthrough infection and help to protect from severe disease. Due to their breadth and ability to target mainly highly conserved epitopes, SARS-CoV-2-specific CD8+ T cells are also able to cross-recognize epitopes of viral variants , thus maintaining immunity even after the emergence of viral evolution. In some cases, however, CD8+ T cells may contribute to the pathogenesis of severe COVID-19. In particular, delayed and uncontrolle...

Situation at a glance On 9 February 2025, officials in the Democratic Republic of the Congo reported to regional health authorities a cluster of 24 unexplained community deaths in a single village in Ekoto health area, Basankusu health zone, Equateur province .  As of 25 February, a total of 53 deaths have been reported , with the last death occurring on 22 February.  Deaths have occurred in all age groups , but adolescents and young adults , particularly males , appeared to be disproportionately affected in the initial cluster reported.  Disease progression appeared to be fast , with a median time from onset of symptoms to death of one day .  Given the rapid decline in the incidence of reported deaths, their geographic clustering, the age profile of deaths and the rapid disease progression in the initial cluster, working hypotheses include chemical poisoning or a rapid onset bacterial meningitis cluster , on a background of malaria and other infectious illnesses end...

 A poultry farm in Sachsen Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6301 _____

A whopper swan was found dead . It was sent to the Swedish Veterinary Agency (formerly National Veterinary Institute) for laboratory analysis as part of the national surveillance program for avian influenza. Source: WOAH,  https://wahis.woah.org/#/in-review/6299 ____

{Summary} In outbreak situations involving a novel pathogen timely and coordinated response is crucial. The WHO Scientific Advisory Group for the Origins of Novel Pathogens recently released a global framework to guide future scientific investigations into the origin of emerging pathogens. Source: Nature Communications,  https://www.nature.com/articles/s41467-025-57218-6 ____

Abstract Highly pathogenic avian influenza viruses (HPAIV) pose a serious public health concern . In March 2024, a first-time outbreak of HPAIV H5N1 in dairy cattle herds was reported in the United States (US). Since then, the virus has continued to spread in cattle herds and spilt over into humans . We recently showed that the first human isolate reported in the US in Texas (HPhTX) from a dairy worker in an affected cattle farm has enhanced replication kinetics and pathogenicity in mice compared to a closely related bovine isolate (HPbTX). However, the molecular determinants of differential pathogenicity have not yet been identified. Herein, we show that HPhTX has enhanced polymerase activity , compared with HPbTX, in human cells and that the polymerase basic 2 (PB2) protein is the main factor responsible for this difference. Through single and combined site-directed mutagenesis and swapping the three amino acids different between HPhTX and HPbTX, we found that PB2 mutation E627K is t...

Abstract In 2020–2021, a “mysterious illness” struck Senegalese fishermen , causing severe acute dermatitis in over one thousand individuals following exposure through drift-net fishing activity . Here, by performing deep analysis of the environmental samples we reveal the presence of the marine dinoflagellate Vulcanodinium rugosum and its associated cyclic imine toxins . Specifically, we show that the toxin PortimineA, strongly enriched in environmental samples, impedes ribosome function in human keratinocytes , which subsequently activates the stress kinases ZAKα and P38 and promotes the nucleation of the human NLRP1 inflammasome, leading to the release of IL-1β/IL-18 pro-inflammatory cytokines and cell death . Furthermore, cell-based models highlight that naturally occurring mutations in the P38-targeted sites of human NLRP1 are unable to respond to PortimineA exposure. Finally, the development and use of human organotypic skins and zebrafish models of PortimineA exposure demonstrat...

  Am J Respir Crit Care Med KERWIN E, Yang T, Su N, Guo J, et al Rademikibart Treatment for Moderate-to-Severe, Uncontrolled Asthma: A Phase 2B Randomized Trial. Am J Respir Crit Care Med. 2025 Feb 25. doi: 10.1164/rccm.202409-1708. PubMed           Abstract available Antiviral Res 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 BMJ MACINTYRE CR, Chughtai AA, Kunasekaran M, Tawfiq E, et al The role of masks and respirators in preventing respiratory infections in healthcare and community settings. BMJ. 2025;388:e078573. PubMed           Abstract avai...

BMC Pediatr MEHDIZADEGAN N, Omidbakhsh S, Shorafa E, Hosseini H, et al Speckle-tracking and conventional echocardiography in MIS-C: tracking cardiac involvement and recovery. BMC Pediatr. 2025;25:137. PubMed           Abstract available BMJ MACINTYRE CR, Chughtai AA, Kunasekaran M, Tawfiq E, et al The role of masks and respirators in preventing respiratory infections in healthcare and community settings. BMJ. 2025;388:e078573. PubMed           Abstract available Epidemiol Infect LIN W, Kung KH, Chan CL, Chuang SK, et al Characteristics and risk factors associated with COVID-19 reinfection in Hong Kong: a retrospective cohort study. Epidemiol Infect. 2025;153:e30. PubMed           Abstract available HOEVE CE, Neppelenbroek N, Vos ERA, Huiberts AJ, et al Using SARS-CoV-2 nucleoprotein antibodies to detect (re)infection. Epidemiol Infect. 2025;153:e38. PubM...

Significance The dominance of the H9N2 subtype of avian influenza virus (AIV) within the influenza A virus family has raised questions regarding the factors influencing its epidemiological dominance . This study concentrates on the role of five major evolutionary patterns of the matrix protein M1 in the replication and transmission of H9N2 AIVs. The findings indicate a strong correlation between the epidemiological dominance of H9N2 AIVs and the specific M1 patterns , particularly M1P5. It highlights the significance of genetic patterns in M1 for understanding the adaptive differences and turnover of epidemiological dominant H9N2 AIVs. Abstract The H9N2 subtype of avian influenza virus (AIV) emerges as a significant member of the influenza A virus family. However, the varying degrees of epidemiological dominance among different lineages or clades of H9N2 AIVs have not been fully clarified. The matrix protein M1 , a key structural component of the virion , plays a crucial role in mainta...

Abstract Using a phylogenetic framework to characterize natural selection , we investigate the hypothesis that zoonotic viruses require adaptation prior to zoonosis to sustain human-to-human transmission . Examining the zoonotic emergence of Ebola virus, Marburg virus, influenza A virus, SARS-CoV, and SARS-CoV-2 , we find no evidence of a change in the intensity of natural selection immediately prior to a host switch , compared with typical selection within reservoir hosts . We conclude that extensive pre-zoonotic adaptation is not necessary for human-to-human transmission of zoonotic viruses. In contrast, the reemergence of H1N1 influenza A virus in 1977 showed a change in selection, consistent with the hypothesis of passage in a laboratory setting prior to its reintroduction into the human population, purportedly during a vaccine trial. Holistic phylogenetic analysis of selection regimes can be used to detect evolutionary signals of host switching or laboratory passage, providing ins...