ETIDIOH - NEW

{Excerpt} This Week : [Date of report - Country - Province / Region District / City - Sex - Age - Condition at time of reporting  - Subtype of virus] 1) .../10/2025 - Cambodia - Takeo Province - F - 14 - Hospitalised - H5N1  2) 16/10/2025 - Cambodia - Kampong Speu Province - F - 3 - Under intensive care - H5N1 (...) [Place of occurrence - No. of cases  (No. of deaths) - Details] -- Bangladesh - 1(0)  - Avian influenza A(H5) :  1) Sylhet Division : A boy with onset on July 27, 2025.  -- Chinese Mainland - 4(0)  - Avian influenza A( H9N2 ):  - Guangdong Province :  1) An individual with onset in February 2025. The case was retrospectively reported.  - Guangxi Zhuang Autonomous Region :  2, 3) Two individuals with onset in February 2025. Both cases were retrospectively reported.   - Tianjin Municipality :  4) An individual with onset in February 2025. The case was retrospectively reported.  -- Mexico - 1(0)  - ...

  Highlights --  We conducted surveillance for influenza A viruses at live bird markets in northern Vietnam. --  Six different subtypes of influenza A virus were found co-circulating in the markets. --  Notable genetic mutations were found across many genes. --  These markets have great potential to generate new pandemic influenza A virus strains. Abstract Objectives Live bird markets (LBMs) in Asia have often been the source of human infections with avian influenza virus (AIV). Methods From July 2021 to August 2023, we employed a One Health approach in conducting periodic surveillance for novel influenza A viruses in five LBMs in northern Vietnam. Specimens were studied with egg culture, molecular assays, Sanger sequencing, and next-generation sequencing. Results We studied a total of 688 human, avian, and bioaerosol specimens . Among these, 118 ( 17.2% ) were found to have molecular evidence of AIVs . Next-generation sequencing of 92 isolates revealed multiple...

  New human cases {1,2}:  -- From 26 August to 29 September 2025 , based on reporting date, the detection of influenza A(H5) in one human , influenza A(H5N1) in one human , influenza A(H9N2) in eight humans and an influenza A(H1N1) variant ((H1N1)v) virus in one human were reported officially.   Circulation of influenza viruses with zoonotic potential in animals :  -- High pathogenicity avian influenza (HPAI) events in poultry and non-poultry animal species continue to be reported to the World Organisation for Animal Health (WOAH).{3}  -- The Food and Agriculture Organization of the United Nations (FAO) also provides a global update on avian influenza viruses with pandemic potential.{4}  Risk assessment {5}:  -- Sustained human to human transmission has not been reported from these events.  -- Based on information available at the time of this risk assessment update , the overall public health risk from currently known influenza A viruses d...

  Abstract The poultry industry faces a constant threat from the mutation and transmission of avian influenza viruses (AIVs). While waterfowl and wild birds are natural hosts of H3N3 AIV , reports of H3N3 infections in chickens are limited. However, in 2023, a decline in egg production among laying hens in the Yancheng Region of Jiangsu Province prompted a study. This research aimed to diagnose the aetiology in laying hens through molecular virological methods and characterise the biological properties of the causative pathogens. An H3N3 AIV subtype strain, A/chicken/China/YC01/2023(H3N3), was isolated from chickens exhibiting lesions. Genome sequencing and analysis revealed a novel genetic makeup : the HA gene originated from an H3N8 AIV, the NA gene from an H10N3 AIV, and the internal genes from an H9N2 AIV, all circulating in China. Chickens experimentally infected with the isolate showed signs of Harderian gland haemorrhage, nasal mucus, tracheal circumferential bleeding , and ...

  New human cases {1,2}:  -- From 2 July to 25 August 2025 , based on reporting date, the detection of influenza A( H5N1 ) in five humans and influenza A(H9N2) in two humans were reported officially.   Circulation of influenza viruses with zoonotic potential in animals :  - High pathogenicity avian influenza (HPAI) events in poultry and non-poultry animal species continue to be reported to the World Organisation for Animal Health (WOAH).{3}  - The Food and Agriculture Organization of the United Nations (FAO) also provides a global update on avian influenza viruses with pandemic potential.{4}  Risk assessment {5}:  - Sustained human to human transmission has not been reported from these events.  - Based on information available at the time of this risk assessment update , the overall public health risk from currently known influenza A viruses detected at the human-animal interface has not changed and remains low .  - The occurrence of sus...

{Summary, excerpts} -- Avian influenza A(H9N2) :  - Anhui Province :  1) A two-year-old boy with onset on August 5, 2025.  - Chongqing Municipality :  2) A six-year-old boy with onset on July 30, 2025.  - Hunan Province 3) A two-year-old boy with onset on August 21, 2025.  - Sichuan Province :  4) A one-year-old boy with onset on July 28, 2025.  (...) Source: Centre for Health Protection, Hong Kong PRC SAR,  https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk36.pdf ____

  Abstract Avian influenza A(H9N2) has been circulating in poultry across Asia, the Middle East, and Africa, posing human health risks . In Ghana , it has co-circulated among poultry with influenza A ( H5N1 ). This report describes Ghana’s first confirmed human case of avian influenza A(H9N2) virus infection in a two-year-old boy from Upper East Region , identified through active respiratory surveillance . Molecular and genomic analyses confirmed the virus was of the G1 lineage , closely related to other West African strains , with mammalian adaptive mutations known to increase human infection potential. The child experienced mild symptoms , received outpatient care, and recovered. Health authorities conducted epidemiological investigations . No source was identified for the child’s infection; no additional human infections were detected. This case highlights the importance of robust avian influenza surveillance in animals and humans, particularly in regions with human-animal inter...

  Abstract Stabilizing the pre-fusion structures of antigenic proteins can enhance the effectiveness of antiviral vaccines . The pre-fusion form of hemagglutinin (HA) from the influenza virus typically adopts a stable trimeric structure . However, the recombinant ectodomain of HA from the A/California/04/2009 (H1N1) influenza virus formed a monomer in solution rather than the expected trimer. To promote trimer formation in the pre-fusion conformation, we redesigned five amino acid residues in the stem region of HA that are involved in trimerization. The engineered HA protein formed a stable trimer at both pH 8.0 and pH 5.5. Additionally, the thermal stability of the modified protein improved, as indicated by an approximately ten-degree increase in its denaturation temperature. Cryo-EM analysis at 2.2 angstrom resolution confirmed that the mutant HA protein adopted the pre-fusion structure. Furthermore, the stabilized mutant exhibited enhanced immunogenicity in mice . We applied the...

  ABSTRACT Alterations in the PB2-627 domain of avian influenza virus (AIV) can potentially increase the risk of cross-host species infections in humans and mammals . Recently, there has been a rise in human cases of AIV infections without the presence of the known mammalian determinant PB2-E627K . Here, we identified a variant, PB2-627V , which has evolved in poultry and has contributed to the increase in human AIV infections . By screening global PB2 sequences , we discovered a new independent cluster of PB2-627V that emerged in the 2010s , prevalent in avian, mammalian, and human AIV isolates , including those of H9N2, H7N9, H3N8, 2.3.4.4b H5N1 , and other subtypes. We functionally assessed its host adaptation , fitness , and transmissibility across three subtypes of AIVs (H9N2, H7N9, and H3N8) in different host models . PB2-627V combines the viral properties of avian-like PB2-627E and human-like PB2-627K , facilitating AIVs to efficiently infect and replicate in chickens and mi...

Abstract Avian influenza A viruses (AIVs) pose a significant pandemic threat due to their cross-species transmission potential . However, AIV surveillance at the critical “ migratory birds–poultry-exposed population ” interface remains limited. Between 2021 and 2024, we implemented a prospective One Health surveillance program around Nansi Lake , monitoring AIVs in migratory birds, poultry, and environmental samples, as well as serological investigations against representative AIVs among migratory birds or poultry-exposed subjects. AIVs were detected in 2.1% (30/1417) of migratory bird samples and 10.2% (100/978) of poultry samples . Among these, we identified ten highly pathogenic avian influenza (HPAI) H5 subtype viruses, one HPAI H7N9 virus, and five low pathogenic avian influenza (LPAI) H9N2 viruses. Phylogenetic analysis revealed evidence of frequent genomic reassortment events involving H5 subtype viruses among migratory birds, poultry, and humans . Serological investigation also...

  {Excerpt} Avian influenza A(H9N2) :  -- Guangdong Province : - 1) An individual with onset on May 28, 2025.  -- Hubei Province :  - 2) An individual with onset on June 21, 2025.  (...) Source: Centre for Health Protection, Hong Kong PRC SAR,  https://www.chp.gov.hk/en/resources/29/332.html ____

  New human cases {2}:  -- From 28 May to 1 July 2025 , based on reporting date, the detection of influenza A( H5N1 ) in nine humans , influenza A( H9N2 ) in three humans and influenza A( H10N3 ) in one human were reported officially. Additionally, one human case of infection with an influenza A(H5N1) virus was detected.  Circulation of influenza viruses with zoonotic potential in animals :  -- High pathogenicity avian influenza (HPAI) events in poultry and non-poultry continue to be reported to the World Organisation for Animal Health (WOAH).{3} The Food and Agriculture Organization of the United Nations (FAO) also provides a global update on avian influenza viruses with pandemic potential.{4}  Risk assessment {5}:  -- Sustained human to human transmission has not been reported from these events.  -- Based on information available at the time of the risk assessment, the overall public health risk from currently known influenza viruses circulating at t...