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Showing posts from March 5, 2025

Impact of highly pathogenic avian #influenza virus on Black-headed #Gulls Chroicocephalus ridibundus population in #Poland in 2023

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...

Real-time #epidemiological #surveillance #data: tracking the occurrences of avian #influenza #outbreaks around the world

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...

Defining transmissible dose 50%, donor #inoculation dose that results in #airborne #transmission to 50% of contacts, for 2 #pandemic #influenza viruses in ferrets

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 ...

#Pathogenicity and #transmissibility of #bovine-derived HPAI #H5N1 #B3.13 virus in #pigs

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...

Evolutionary Studies on the #Coxsackievirus A24 #Variants Causing Acute #Hemorrhagic #Conjunctivitis with Emphasis on the Recent #Outbreak of 2023 in #India

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...