ETIDIOH - NEW

  {Summary} Time Period: September 14, 2025 - September 20, 2025 -- H5 Detection :  3 sites ( 0.7% ) -- No Detection :  429 sites ( 99.3% ) -- No samples in last week :  33 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

{Di Donna Dewhurst - This image originates from the National Digital Library of the United States Fish and Wildlife Service,   https://commons.wikimedia.org/w/index.php?curid=269880 } The affected wild animals {Anatidae spp.} belonged to a conservation foundation; they got sick after sharing water bodies with migratory birds. Location: Izabal Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6814 ____

  {Summary} -- During current surveillance week (from 18 to 24 Sept. '25), 33 new confirmed human cases of West Nile Virus have been detected.  -- Since the beginning of the epidemic season , there have been 680 cases in total , (they were 647 last week); of these:  - 321 were West Nile Neuroinvasive Disease (WNND): 15 in Piedmont, 44 Lombardy, 27 Veneto, 2 Friuli-Venezia Giulia, 1 Liguria, 25 Emilia-Romagna, 8 Tuscany, 1 Marche, 83 Latium, 2 Molise, 79 Campania, 2 Apulia, 2 Basilicata, 5 Calabria, 1 Sicily, 24 Sardinia),  - 54 were asymptomatic cases in blood donors ,  - 296 were West Nile Fever cases (1 imported from Kenya , 1 Egypt and 1 Maldives ),  - 3 asymptomatic cases,   - 6 unspecified cases.  --  Among confirmed cases , there were 48 deaths : 7 in Piedmont, 5 Lombardy, 2 Emilia-Romagna, 17 Latium, 14 Campania, 2 Calabria, 1 Sardinia.  - The Case-Fatality Rate among WNND cases was 14.9% (it was 20% in 2018 and 14% in 2024)....

  {Excerpt} Highly pathogenic avian influenza caused by H5N1 viruses emerged in East Asia in the late 1990s and spread to Europe, Africa, and the Middle East , circulating in wild and domestic birds and occasionally spilling over into mammals and humans . These viruses are classified into genetic lineages called clades based on differences in the gene encoding hemagglutinin , a key surface protein involved in cell entry. In 2021, one such lineage, clade 2.3.4.4b , crossed from Europe to Canada . It spread rapidly, reaching the southern tip of South America in less than 2 years and causing massive mortality in seabirds and marine mammals , including South American sea lions (Otaria flavescens) and southern elephant seals (Mirounga leonina) (1). However, human mortality has been markedly lower in the present H5N1 outbreak than in past ones. If the virus evolves the capacity to transmit from human to human, understanding this reduction will be essential for mounting an effective respo...

  Abstract Influenza virus cross-subtype antibodies targeting the hemagglutinin (HA) head are rare . Here, we found that a large proportion of monoclonal antibodies (mAbs) isolated from individuals immunized with the 2021-22 seasonal influenza vaccine bound to an epitope on the HA head of both the H1N1 vaccine strain and H3N2 strains from the mid-1990s. These H1/H3 cross-reactive antibodies were also found in polyclonal sera , but only in samples from individuals born in the 1990s . Ferrets sequentially exposed to an H3N2 virus from the 1990s and a contemporary seasonal influenza vaccine produced the same type of H1/H3 cross-reactive antibodies. We found evidence that H1N1 viruses are currently evolving within the human population to abrogate the binding of these antibodies . Together, our study demonstrates how prior influenza virus exposures can influence the specificity of antibodies elicited by entirely different influenza virus subtypes, and how viruses evolve to escape these ...