ETIDIOH - NEW

  Situation at a glance In 2025, a resurgence of chikungunya virus (CHIKV) disease was noted in a number of countries , including some that had not reported substantial case numbers in recent years.  Between 1 January and 30 September 2025, a total of 445 271 suspected and confirmed CHIKV disease cases and 155 deaths were reported globally from 40 countries , including autochthonous and travel imported cases.  Some WHO Regions are experiencing significant increases in case numbers compared to 2024, although others are currently reporting lower case numbers.  This uneven distribution of cases across regions makes it challenging to characterize the situation as a global rise, however, given the ongoing outbreaks reported globally in 2025, the potential for further spread remains significant .  CHIKV disease can be introduced into new areas by infected travelers and local transmission may be established if there is the presence of Aedes mosquito and a susceptible p...

  {Summary} -- During current epidemiological week (from  25 September to 1rst October 2025),  38 new confirmed human infection with West Nile Virus have been reported.  -- Since the beginning of the epidemic season, 718 confirmed cases have been recorded in Italy (they were 680 in the last bulletin), of these:  - 341 were West Nile Neuroinvasive Disease (WNND): 15 in Piedmont, 51 Lombardy, 30 Veneto, 4 Friuli-Venezia Giulia, 1 Liguria, 27 Emilia-Romagna, 11 Tuscany, 1 Marche, 84 Latium, 2 Molise, 79 Campania, 2 Apulia, 2 Basilicata, 5 Calabria, 2 Sicily, 25 Sardinia,  - 57 were asymptomatic cases in blood donors ,  - 309 were West Nile Fever cases (1 imported from Kenya , 1 Egypt , and one Maldives ),  - 4 asymptomatic cases,  - 7 unspecified cases.  -- Among confirmed cases , there have been 49 fatalities : 7 in Piedmont, 5 Lombardy, 2 Emilia-Romagna, 18 Latium, 14 Campania, 2 Calabria, 1 Sardinia.  - The Case-Fatality Rate in WNN...

  Abstract In China, low pathogenic avian influenza (LPAI) H3N8 virus is widespread among chickens and has recently caused three zoonotic infections , with the last one in 2023 being fatal . Here we evaluated the relative pandemic risk of this 2023 zoonotic H3N8 influenza virus, utilizing our previously published decision tree. Serological analysis indicated that a large proportion of the human population does not have any cross-neutralizing antibodies against this H3N8 strain. LPAI H3N8 displayed a dual affinity for a2-3 and a2-6 sialic acids and replicated efficiently in human bronchial epithelial cells . Furthermore, we observed H3N8 transmission via direct contact but not aerosols to ferrets with pre-existing H3N2 immunity. Although pre-existing H3N2 immunity resulted in a shortened disease course in ferrets, it did not reduce disease severity or replication in the respiratory tract. This study suggests that this zoonotic H3N8 strain has moderate pandemic potential and emphasiz...

  Abstract In 2024, a human infection with clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) virus was identified in the United States in an individual with no known exposure . Genetic analysis revealed two hemagglutinin (HA) substitutions, P136S and A156T, which may alter viral antigenicity . Virus isolation was unsuccessful, preventing timely serologic analysis. To overcome this limitation, we generated recombinant viruses by reverse genetics and characterized the effects of the substitutions on antigenicity, receptor binding , and replicative fitness. The A156T substitution introduced a potential N-linked glycosylation site , resulting in altered antigenicity and reduced replication in primary human nasal epithelial cells and ferrets . Importantly, the A(H5N1) candidate vaccine virus (CVV) IDCDC-RG80A, which possesses HA-T156, remained antigenically effective against viruses with and without these substitutions. These findings highlight the importance of sequencing, rever...

  Abstract In North-East Germany's offshore islands and mainland coast, wild ruminants, boar, and carnivores were tested for H5-HPAI antibodies . Wild ruminants were seronegative ; 3.5% of boar and 12.5-21.9% of carnivores were seropositive , evidencing frequent spillover . Because such events may accelerate mammalian - and ultimately human - adaptation , sustained One-Health monitoring is essential. Competing Interest Statement The authors have declared no competing interest. Funder Information Declared European Union, 101084171 "KAPPA-FLU" Helmholtz Institute for One Health, WiMoPOH Source: BioRxIV,  https://www.biorxiv.org/content/10.1101/2025.09.30.678011v1 ____

  A laying hens farm in Nordrhein-Westfalen Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6832 ____

  Date of issue : 30 September 2025 Data as reported by : 28 September 2025 {Summary} The Ebola virus disease outbreak in the Democratic Republic of the Congo continues, with signs of a notable decline in transmission .  Since our last update (Situation Report #2), a total of seven new cases have been reported, comprising six confirmed and one probable cases (retrospectively validated).  The new cases were detected across three health areas within Bulape Health Zone , namely, Bulape (n=4), Mpianga (n=2), and Dikolo (n=1).  During the same reporting period , seven deaths occurred among newly identified and previously hospitalized cases. The reported deaths were distributed across Dikolo (n=3), Bulape (n=2), Mpianga (n=1), and Bulape Communitaire (n=1) health areas. As of 28 September 2025, a total of 64 cases (53 confirmed and 11 probable), including 42 deaths (31 confirmed, 11 probable), have been reported from Bulape Health Zone, Kasai Province , Democratic Republic...

  Summary Background Post-acute sequelae of SARS-CoV-2 infection (PASC) remain a major public health challenge . Although previous studies have focused on characterising PASC in children and adolescents after an initial infection , the risks of PASC after reinfection with the omicron variant remain unclear. We aimed to assess the risk of PASC diagnosis (U09.9) and symptoms and conditions potentially related to PASC in children and adolescents after a SARS-CoV-2 reinfection during the omicron period. Methods This retrospective cohort study used data from 40 children's hospitals and health institutions in the USA participating in the Researching COVID to Enhance Recovery (RECOVER) Initiative. We included patients younger than 21 years at the time of cohort entry; with documented SARS-CoV-2 infection after Jan 1, 2022; and who had at least one health-care visit within 24 months to 7 days before the first infection. The second SARS-CoV-2 infection was confirmed by positive PCR, antigen...

  {By © Hans Hillewaert, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=5548312 } Wild species: Black-headed Gull (8), Mew Gull (8). {Norðurland vestra Region} Approximately 20 gulls were found dead at the beach. A pooled sample from 3 mew gulls was taken and found positive for HPAI H5N5. {Icelandic Exclusive Economic Zone} Approximately 20 gulls were found dead at the beach. A pooled sample from 3 black-headed gulls was taken and found positive for HPAI H5N5. Source: WOAH,  https://wahis.woah.org/#/in-review/6816 ____

  {England, Cumberland} A chicken breeders flock of 43,339 birds. Increased mortality and other clinical signs (lethargy, respiratory distress, swollen heads, tremors, watery diarrhoea and excessive oral discharge) were reported. Samples taken and were tested positive for HPAI H5N1. Source: WOAH,  https://wahis.woah.org/#/in-review/6824 ____

  {By Andreas Trepte - Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=37690004 } A wild Whooper Swan in Vidzemes Region. Source:  https://wahis.woah.org/#/in-review/6825 ____

  The highly pathogenic avian influenza virus (HPAI), subtype H5N1 - has been detected in a commercial farm of laying hens located in the Municipality of Roverbella, Mantova Province, Lombardia region. The highly pathogenic avian influenza virus (HPAI), subtype H5N1 - has been detected in a commercial farm of laying hens located in the Municipality of Cerasara, Mantova Province, Lombardia region. The highly pathogenic avian influenza virus (HPAI), subtype H5N1 - has been detected in a commercial farm of broiler located in the Municipality of Chivasso, Torino Province, Piemonte region. The highly pathogenic avian influenza virus (HPAI), subtype H5N1 - has been detected in a commercial farm of laying hens located in the Municipality of Vigasio, Verona Province, Veneto region. The highly pathogenic avian influenza virus (HPAI), subtype H5N1 - has been detected in a commercial farm of laying hens located in the Municipality of Sona, Verona Province, Veneto region. The highly pathogenic...

  Abstract Since 2020, the outbreak of high pathogenicity avian influenza (HPAI) H5N1 virus clade 2.3.4.4b has turned into the largest documented panzootic 1,3. Here, we describe its arrival into the Indian Ocean sub-Antarctic archipelagos of Crozet and Kerguelen , where we first detected the virus in October 2024 in dead southern elephant seals . While the panzootic is ongoing, it has already caused unprecedented mortalities of marine mammals and seabirds . We collected brain swabs from seal and seabird carcasses and obtained 25 novel HPAI H5N1 2.3.4.4b sequences . Using phylogeographic analyses, we show that there have been independent introductions of the virus to Crozet and Kerguelen islands , most likely from the distant South Georgia islands in the Southern Atlantic , and not from the more nearby coasts of South Africa . Our results point to a year-long gap in genomic surveillance in the sub-Antarctic region. Locally, our analyses show that the virus is transmitted between di...

Wild Mute Swans in the Kärnten Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6821 ____

  Highlights •  Raw pet foods and raw milk are emerging sources of H5N1 in pets . •  Cats are more severely infected with H5N1 when compared to dogs. •  H5N1 persistence in mammals indicate adaptive variants with increased zoonotic potential. •  No reported pet-to-human transmission of H5N1 has been reported. •  FDA now requires RMBD makers who are covered under FSMA to assess HPAI risk. Abstract The increasing popularity of raw meat-based diets (RMBDs) and raw milk feeding in companion animals presents a growing concern for zoonotic disease transmission. Recent evidence has demonstrated that these products can serve as vehicles for highly pathogenic avian influenza (HPAI) H5N1 , an emergent viral threat with a host range from birds, dairy cattle , and pets to humans . Since the emergence of clade 2.3.4.4b in 2020 , HPAI H5N1 has caused widespread outbreaks in poultry, wild birds, and mammals , including dairy cattle and cats . Transmission to pets has been...

  Abstract The emergence of H5N1 highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.4b in dairy cattle across multiple U.S. states in early 2024 marks a major shift in the virus’s host range and epidemiological profile . Traditionally limited to bird species , the ongoing detection of H5N1 in cattle , a mammalian host not previously considered vulnerable, raises urgent animal and human health concerns about zoonoses and mammalian adaptation . We assessed the feasibility of using commercially available pasteurized milk as a sentinel matrix for the molecular detection and genetic characterization of H5N1 HPAIV. Our aim was to determine whether retail milk could serve as a practical tool for virological monitoring and to evaluate the use of full-length genome segment amplification for extracting genomic sequence information from this highly processed matrix. Our results link HPAIV sequences in store-bought milk to the cattle outbreak and highlight both the potential and the l...

Public Domain. Source: WikiArt,  https://www.wikiart.org/en/domenico-ghirlandaio/portrait-of-giovanna-tornabuoni-1490  ____

  Abstract In March 2024, a highly pathogenic avian influenza H5N1 (HPAI) clade 2.3.4.4b virus was identified in US dairy cows , with spillover to cats, poultry, and humans . Up to 30% of commercial pasteurized milk tested contained viral genome copies . The impact of residual viral remnants on host immunity is unknown. Orally ingested proteins can stimulate gut-associated lymphoid tissues , potentially inducing tolerance and altering responses to later infection. We found that milk pasteurization fully inactivated pandemic H1N1 and bovine H5N1 influenza viruses yet preserved hemagglutinin (HA) protein integrity. In mice , repeated oral exposure to inactivated virus did not alter mortality after H5N1 virus challenge. Preliminary data showed that naïve mice exposed to improperly pasteurized milk containing live H5N1 virus developed lethal infection , whereas prior H1N1 infection conferred protection . Mice with preexisting H1N1 immunity remained protected when challenged with bovine...

  Von Hmaag - Eigenes Werk, CC BY-SA 3.0,  https://commons.wikimedia.org/w/index.php?curid=9531230 Source: Wikipedia,  https://de.wikipedia.org/wiki/Schweizerische_Lokomotiv-_und_Maschinenfabrik ____

  Int J Infect Dis TENG Z, Li L, Che T, Liang J, et al A Novel Balamuthia Lineage Causing Fatal Granulomatous Amoebic Encephalitis in an Immunocompetent Infant. Int J Infect Dis. 2025 Sep 17:108063. doi: 10.1016/j.ijid.2025.108063. PubMed           Abstract available J Med Virol PLICANTI E, Deiana A, Nottoli S, Lottini G, et al A Pyrido-Quinoxaline Derivative That Downregulates Reticulon 3 Protein Exhibits Potent Antiviral Activity Against Zika Virus. J Med Virol. 2025;97:e70605. PubMed           Abstract available J Virol TSUJINO S, Tsuda M, Nao N, Okumura K, et al Evolution of BA.2.86 to JN.1 reveals that functional changes in non-structural viral proteins are required for fitness of SARS-CoV-2. J Virol. 2025 Sep 23:e0090825. doi: 10.1128/jvi.00908. PubMed           Abstract available HAMMER E, Flynn C, Rossler J, Erder J, et al Prediction of COVID-19 disease pr...