ETIDIOH - NEW

Abstract Gammacoronavirus (γ-CoV) primarily infects poultry, wild birds, and marine mammals . The widespread distribution and circulation of γ-CoV in the ecological environment may lead to sustained transmission and economic loss . To better understand the diversity of γ-CoV in wild birds , we collect 482 wild-bird fecal samples from Yunnan , encompassing fourteen bird species . We detected twelve γ-CoV positive samples in five bird species, with the characterization of five complete genomes - HNU5-1, HNU5-2, HNU5-3, HNU6-1, and HNU6-2 -indicating that these genomes represent two viral species . The HNU5 strains were derived from Black-headed gull (Chroicocephalus ridibundus), while the HNU6 strains were came from Mallard (Anas platyrhynchos), and both of those were recombinant. The HNU5 strain exhibited the highest sequence identity (95.45%) with a γ-CoV strain isolated from Numenius phaeopus (GenBank accession: PP845452). Similarly, the HNU6 strain showed 95.18% nucleotide identity w...

{Excerpt} Avian influenza A(H9N2) :  -- Guangxi Zhuang Autonomous Region :  - A five-year-old boy with onset on March 3, 2025.  -- Guizhou Province :  - A 35-year-old woman with onset on March 10, 2025.  -- Henan Province - A seven-year-old girl with onset on February 11, 2025.  (...) Source: Centre for Health Protection, Hong Kong PRC SAR,  https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk15.pdf ____

Abstract In November 2022, we reported a fatal case of human infection caused by a highly pathogenic avian influenza A(H5N6) virus bearing a clade 2.3.4.4b HA gene in Changsha City . We investigated the transmission route and distribution of the H5N6 virus in the largest live-poultry market (LPM), which is linked to the human infection. A total of 1357 samples from the LPM were collected for avian influenza A virus detection from 2020 to 2023. The proportion of LPM samples positive for H5 subtype avian influenza virus was 14.30% (194/1357). Sequences of H5N6 (n = 10) and H5N1 (n = 4) avian influenza viruses were obtained from the LPM samples using next-generation sequencing. The complete genome sequence of the H5N6 virus from the human infection case, A/Changsha/1/2022(EPI_ISL_16466440), was determined and analyzed. The PB1 and PB2 segments shared 99.65% and 99.23% sequence identity with A/duck/Hunan/S40199/2021(H5N6) and A/Whooper swan/Sanmenxia/H615/2020(H5N8), respectively. The othe...

Abstract Objective :  To analyze the epidemiological, etiological and genetic characteristics of influenza virus in Shandong Province during 2023-2024.  Methods :  The surveillance data of influenza-like illness (ILI) in sentinel hospitals in Shandong from 2023 to 2024 were collected and analyzed. The isolated influenza strains with hemagglutination titers ≥8 were selected for antigenicity analysis , drug susceptibility test, gene sequencing and evolutionary analysis .  Results :  From 2023 to 2024, the positive rate of influenza virus in Shandong was 8.51% (23 663/277 995), the highest positive rate was in the age group of 5-14 years (15.78%, 6 073/38 478), and the highest positive rate was in the 49th week (35.86%, 2 264/6 313). Both antigenicity analysis and evolutionary analysis showed that the A(H1N1)pdm09 subtype and B(Victoria) strain had good matching effect and close evolutionary distance with the 2023-2024 surveillance year vaccine strain. The A(H3N2) ...

Highlights •  Scientific question :  Cross-species transmission of influenza A viruses from swine to humans occurs occasionally because their tracheal epitheliums possess both sialic acid α-2,6-Gal and α-2,3-Gal receptors . In 2011, the first human case of swine influenza virus infection in the mainland of China was detected in Jiangsu Province . Subsequently, the Eurasian avian-like H1N1 swine influenza virus (EAH1N1 SIV) had sporadically crossed the host barrier and infected humans, raising public concern for its pandemic potential. •  Evidence before this study :  A/Jiangsu/1/2011 (H1N1v) was first discovered in 2011 and belongs to the G1 genotype. The G4 and G5 genotypes that appeared successively in 2013 are recombinant H1N1 swine influenza viruses. The EAH1N1 SIVs from 2016 to the present are dominated by the G4 genotype, with hemagglutination (HA) and neuraminidase (NA) genes derived from the EAH1N1 SIVs, non-structural protein (NS) genes derived from the trip...

Abstract Background In late 2023, the first human case caused by an H10N5 avian influenza virus (AIV) was diagnosed in China . H10Ny AIVs have been identified in various poultry and wild birds in Eurasia, the Americas, and Oceania. Methods We analyzed the clinical data of the H10N5 AIV-infected patient, isolated the virus, and evaluated the virus receptor-binding properties together with the H10N8 and H10N3 AIVs identified in humans and poultry. The genomic data of the human-infecting H10N5 strain and avian H10Ny AIVs (n = 48, including 16 strains of H10N3 and 2 strains of H10N8) from live poultry markets in China , during 2019–2021, were sequenced. We inferred the genetic origin and spread pattern of the H10N5 AIV using the phylodynamic methods. In addition, given all available nucleotide sequences, the spatial-temporal dynamics, host distribution, and the maximum-likelihood phylogenies of global H10 AIVs were reconstructed. Findings The first H10N5 AIV-infected human case co-infected...

Abstract Since 2022, three cases of human infections of novel H3N8 avian influenza viruses (AIVs) have been confirmed in China . Given the potential for significant public health implications , the prompt detection and containment of the virus is particularly important. Comprehensive analyses were conducted of the complete viral gene sequences of five H3 subtype AIVs that were isolated from chickens, pigeons, and geese in live poultry markets in China in 2023. Four strains exhibited a high degree of homology with the H3N8 viruses responsible for human infections in 2022 and 2023. A subsequent study was conducted to investigate the pathogenicity differences among multiple subtypes of the H3 AIVs in chickens. The study revealed that all infected chickens exhibited clinical signs and viral shedding. Notably, two H3N8 viruses, which were highly homologous to human strains, demonstrated significant differences in adaptability to chickens. The goose-derived H3N5 strain displayed high adaptab...

 {Excerpt} {Avian Influenza H9N2 Human Cases in China} -- Mainland China:  2 cases (0 death)  - Avian influenza A(H9N2):  * Guangdong Province :  - A 72-year-old woman with onset on December 26, 2024.  - A 56-year-old woman with onset on January 20, 2025.  (...) Source: Centre for Health Protection, Hong Kong PRC SAR,  https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk07.pdf ____

Abstract During our surveillance of avian influenza viruses (AIVs) in wild birds across China , H10Nx viruses were isolated from diverse migratory flyways between 2022 and 2024. We identified one wild-bird H10N5 strain that shared a common ancestor with the human H10N5 virus in multiple gene segments. Phylogenetic and molecular dating revealed the origin and evolution of H10N5, highlighting the need for continued monitoring. Source: Emerging Microbes and Infections,  https://www.tandfonline.com/doi/full/10.1080/22221751.2025.2465308 ____

Abstract The H9N2 subtype of avian influenza virus poses significant challenges to global poultry and human health . During the active surveillance of avian influenza virus in wild birds in Shanghai from 2020 to 2023, a total of nine H9N2 viruses were identified. To better understand the genetic characteristics of these H9N2 viruses in Shanghai, the whole genome sequences were analyzed. Phylogenetical analysis showed that the nine H9N2 viruses have undergone complicated reassortment with waterfowl viruses along the East Asian-Australasian flyways . The nine H9N2 viruses were classified into seven genotypes , and some of them could contribute internal genes to recently circulating HPAI A( H5N8 ) and A( H5N1 ) viruses of clade 2.3.4.4b. These results highlight the importance of active surveillance of AIVs in wild birds to comprehend viral ecology and evaluate potential transmission risk in poultry and humans. Source: Poultry Sciences,  https://www.sciencedirect.com/science/article/pi...

 {Excerpt} Avian Influenza Report - VOLUME 21, NUMBER 6 - Reporting period: Feb 2, 2025 – Feb 8, 2025 (Week 6), (Published on February 11, 2025)  -- Mainland China: 2 new cases (0 death cases):  - Avian influenza A(H9N2) :  - Hunan Province :  - 1) A two-year-old boy with onset on December 27, 2024.   - 2) A 15-year-old boy with onset on January 8, 2025.  (...) Source: Centre for Health Protection, Hong Kong PRC SAR,  https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk06.pdf _____

Abstract As a rare subtype of avian influenza virus, H16 viruses are predominant in gulls but rarely found in domestic birds . The low prevalence of H16 viruses has limited our understanding of their epidemiology and evolutionary dynamics . In this study, we isolated three novel H16N3 viruses from migratory gulls in East Asian–Australasian Flyway in eastern China in 2023, which are significantly different from previously identified isolates. To fully understand the epidemiology and genetics characteristics of the global H16 viruses, we compared the host divergence of several rare subtypes and determined that the H13 and H16 subtypes were predominantly pooled into different species of gulls by sharing their internal genes, whereas the waterfowl of Anatidae served as the primary natural reservoirs of the H8, H11, H12, H14, and H15 subtypes. Detailed phylogenetic analysis revealed the evolutionary divergence of globally circulating H16 viruses and their frequent gene reassortment . Furthe...

Abstract Background :  In 2024, mainland China witnessed a significant upsurge in Hand, Foot, and Mouth Disease (HFMD) cases. Coxsackievirus A16 (CVA16) is one of the primary causative agents of HFMD. Long-term monitoring of theCVA16 infection rate and genotype changes is crucial for the prevention and control of HFMD.  Methods :  A total of 40,673 clinical specimens were collected from suspected HFMD cases in Guangdong province from 2018 to 2024, including rectal swabs (n = 27,954), throat swabs (n = 6791), stool (n = 5923), cerebrospinal fluid (n = 3), and herpes fluid (n = 2). A total of 24,410 samples were detected as EV-positive and further typed by RT-PCR. A total of 872 CVA16-positive samples were isolated and further sequenced to obtain the full-length VP1 sequence. Phylogenetic analysis was performed based on viral protein 1 gene (VP1).  Results :  In the first 25 weeks of 2024 , reported cases of HFMD were 1.36 times higher than the mean rates of 2023 ...

Abstract Wild birds and waterfowl serve as the natural reservoirs of avian influenza viruses (AIVs). When AIVs originating from wild birds cross species barriers to infect mammals or humans , they pose a significant threat to public health . The H12 subtype of AIVs primarily circulates in wild birds, with relatively few isolates reported worldwide , and the evolutionary and biological characteristics of H12 subtype AIVs remain largely unknown. In this study, we analyzed the spatiotemporal distribution of H12 subtype AIVs worldwide and conducted a comprehensive investigation into the evolutionary and biological characteristics of an H12N2 virus isolated from a whooper swan in Central China . Phylogenetic analysis revealed that the H12N2 isolate belongs to the Eurasian lineage , with its HA gene likely originating from a duck-derived H12N5 virus and its NA gene potentially derived from an H9N2 virus , indicating that it is a complex reassorted virus. Animal experiments in domestic ducks ...

{Excerpt} Dear Editor, The highly pathogenic avian influenza viruses (HPAIVs) are important epizootic and zoonotic pathogens that cause significant economic losses to the poultry industry and pose a serious risk to veterinary and public health . Wild birds have been recognized as the primary reservoirs for influenza A virus, and some species show little sign of clinical disease or even can be asymptomatic during long distance carriers of the virus (Lycett et al., 2019). Since it was first discovered in 1959, the H5Nx HPAIVs have spread globally and cause outbreaks in wild birds, poultry and sporadic human and other mammalian infections (Lycett et al., 2019). Due to the reassortant events of diverse strains facilitated by migratory waterfowl, the clade 2.3.4.4 of H5Nx viruses acquiring neuraminidase (NA) gene from other low pathogenicity avian influenza viruses (LPAIVs) emerged in 2014 and gradually became the dominant sub-clade (Lee et al., 2017). The genetic diversity of clade 2.3.4.4...

Abstract The effectiveness of poultry vaccination in preventing the transmission of highly pathogenic avian influenza viruses (AIVs) has been debated, and its impact on wild birds remains uncertain. Here, we reconstruct the movements of H5 subtype AIV lineages among vaccinated poultry , unvaccinated poultry, and wild birds, worldwide, from 1996 to 2023. We find that there is a time lag in viral transmission among different host populations and that movements from wild birds to unvaccinated poultry were more frequent than those from wild birds to vaccinated poultry . Furthermore, our findings suggest that the HA (hemagglutinin) gene of the AIV lineage that circulated predominately in Chinese poultry experienced greater nonsynonymous divergence and adaptive fixation than other lineages. Our results indicate that the epidemiological, ecological, and evolutionary consequences of widespread AIV vaccination in poultry may be linked in complex ways and that much work is needed to better under...

Abstract H4Nx avian influenza viruses (AIVs) have been isolated from wild birds and poultry and can also cross the species barrier to infect mammals ( pigs and muskrats ). The widespread presence of these viruses in wild birds and poultry and their ability to be transmitted interspecies make them an undeniable hazard to the poultry farming industry. In the present study, we collected fecal and swab samples from wild birds and poultry in Guangdong Province from January 2019 to March 2024, and various subtypes of AIVs were isolated, including 19 strains of H4 subtype AIVs . Further analysis was conducted on the internal genes of the 19 strains . These strains clustered together with high homology to highly pathogenic avian influenza virus (HPAIV), suggesting that H4Nx AIV may be reassorted from HPAIV . Two H4N8 strains are phylogenetically related to the porcine H4N8 AIV. Molecular characterization revealed that all viruses in this study were less pathogenic but had potential mammalian-a...

 {Excerpt} -- Avian influenza A(H9N2) : -- 1) Chongqing Municipality : An one-year-old girl with onset on December 13, 2024.  -- 2) Hubei  An eight-year-old girl with onset on November 27, 2024.  -- Avian influenza A(H10N3) :  -- 1) Guangxi Zhuang Autonomous Region : A 23-year-old woman with onset on December 12, 2024.  Source: Centre for Health Protection, Hong Kong PRC SAR,  https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk02.pdf _____

Abstract Understanding wildlife-pathogen interactions is crucial for mitigating zoonotic risk . Through meta-transcriptomic sequencing we profiled the infectomes of 1,922 samples from 67 mammalian species across China , uncovering a remarkable diversity of viral, bacterial, fungal, and parasitic pathogens. Of the 195 pathogens identified , 62 were novel , including a bi- segmented coronavirus in diseased lesser pandas, which we propose represents a new genus – Zetacoronavirus . The orders Carnivora and Rodentia exhibited the highest pathogen diversity and were implicated in numerous host-jumping events. Comparative analysis of diseased versus healthy animals revealed a trend of higher pathogen loads in the former, with possible differences in tissue tropisms. In total, 48 zoonotic and 17 epizootic pathogens were identified, with frequent cross-species transmission , emphasizing the potential for emerging public health threats. This study highlights the urgent need for wildlife pathogen...

Situation at a glance In many countries of the Northern Hemisphere , trends in acute respiratory infections increase at this time of year.  These increases are typically caused by seasonal epidemics of respiratory pathogens such as seasonal influenza, respiratory syncytial virus (RSV), and other common respiratory viruses , including human metapneumovirus (hMPV), as well as mycoplasma pneumoniae .  Many countries conduct routine surveillance for acute respiratory infections and common respiratory pathogens.  Currently, in some countries in the temperate Northern hemisphere, influenza-like illness (ILI) and/or acute respiratory infection (ARI) rates have increased in recent weeks and are above baseline levels, following usual seasonal trends.  Seasonal influenza activity is elevated in many countries in the Northern hemisphere.  Where surveillance data is available , trends in RSV detections currently vary by region with decreases reported in most regions except ...