ETIDIOH - NEW

Abstract Double-crested Cormorants (Nannopterum auritum) have historically exhibited low levels of infection and antibodies to avian influenza virus (AIV). The recent global expansion of clade 2.3.4.4b A/goose/Guangdong/1/1996 highly pathogenic (HP) avian influenza virus H5N1 (HPAI H5N1) has resulted in large-scale mortalities across diverse waterbird taxa including cormorants . We sampled 32 and 29 Double-crested Cormorants breeding in the Chesapeake Bay, US , during the summers of 2023 and 2024, respectively, to assess HPAI H5N1 infection and AIV antibodies. Although no mortality was observed in the area, one bird sampled in 2023 was infected with HPAI H5N1. Additionally, 21/31 individuals in 2023 and 10/25 individuals in 2024 for which sera were collected had AIV antibodies . Based on additional testing using hemagglutination inhibition, virus neutralization , and an enzyme-linked lectin assay , 94 and 100% (2023 and 2024, respectively) of the seropositive birds tested positive for ...

Abstract After nearly a decade without reported human A/H5N1 infections , Cambodia faced a sudden resurgence with 16 cases between February 2023 and August 2024, all caused by A/H5 clade 2.3.2.1c viruses . Fourteen cases involved a novel reassortant A/H5N1 virus with gene segments from both clade 2.3.2.1c and clade 2.3.4.4b viruses. The emergence of this novel genotype underscores the persistent and ongoing threat of avian influenza in Southeast Asia . This study details the timeline and genomic epidemiology of these infections and related poultry outbreaks in Cambodia. Source: MedRxIV,  https://www.medrxiv.org/content/10.1101/2024.11.04.24313747v2 _____

 One Cygnus species wild bird in Sachsen Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6245 _____

Abstract Since early-2024 unprecedented outbreaks of highly pathogenic avian influenza H5N1 clade 2.3.4.4b have been ongoing in dairy cattle in the United States with significant consequences for the dairy industry and public health. Estimation of key epidemiological parameters is required to support outbreak response, including predicting the likely effectiveness of interventions and testing strategies. Here we pool limited publicly available data from three studies of naturally and experimentally infected dairy cattle. We quantify Ct value trajectories of infected dairy cattle and the relationship between Ct value and the log-titre of infectious virus, a proxy for infectiousness. We estimate that following infection peak Ct values are rapidly reached within 1--2 days with a population mean Ct value of 16.9 (13.2, 20.5). We identify a critical threshold Ct value of 21.5 (20.1, 23.6), with values of Ct value above this threshold representing little-to-no infectious viral load. Finally,...