ETIDIOH - NEW

  Abstract The Goose/Guandong lineage of highly pathogenic avian influenza virus [A/Goose/Guangdong/1/1996(H5N1)] is the progenitor of the currently circulating Eurasian-lineage highly pathogenic avian influenza H5N1 clade 2.3.4.4b and has been the most consequential highly pathogenic avian influenza lineage globally. Despite increased reports of infections, the extent of exposure and role of wild mammals in the ecology and transmission dynamics of the virus remains poorly understood. We surveyed wild mammals in Ohio, United States to investigate the potential spillover of highly pathogenic H5N1 avian influenza clade 2.3.4.4b. While no active infections —defined as positive results indicative of viral replication and potential propagation—were detected by swab-based molecular tests, serological assays revealed antibodies against multiple avian influenza virus antigens in raccoons and opossums . Specifically, antibodies to avian influenza virus nucleoprotein were detected in 54.9% (...

  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...

  Abstract Wastewater surveillance of respiratory pathogens can provide timely estimates of viral activity and disease trends in a population . Indoor air surveillance could be used similarly with some advantages but remains largely unvalidated at the community-scale. Here, an indoor air surveillance program was employed as part of public health environmental surveillance in Chicago, Illinois , USA. Ten air samplers were placed in healthcare and congregate living settings across the city. Weekly air samples were evaluated for influenza A, influenza B, respiratory syncytial virus, and SARS-CoV- 2 over two respiratory virus seasons. Citywide, aggregated air sample positivity and viral load were closely correlated with local clinical case and wastewater surveillance data across all respiratory viruses. Virus trends in air data often preceded clinical and wastewater, although this varied across pathogens and respiratory virus seasons. Further, whole-genome sequencing of SARS-CoV-2 show...

  ALBANY, N.Y. (October 14, 2025) — The New York State Department of Health today announced that a case of locally acquired chikungunya has been confirmed in New York State . Laboratory testing at the Department's Wadsworth Center confirmed the case in Nassau County on Long Island . This marks the first locally acquired case of chikungunya reported in New York State . No locally acquired cases have been reported in the U.S. states and territories since 2019. An investigation suggests that the individual likely contracted the virus following a bite from an infected mosquito . While the case is classified as locally acquired based on current information, the precise source of exposure is not known. The Aedes albopictus mosquito , known to transmit chikungunya, is present in parts of downstate New York. Local transmission can occur when an A. albopictus mosquito bites an infected traveler, becomes infected and bites another person. The disease cannot be spread directly from one person...

  Abstract Avian influenza A viruses pose ongoing threats to human and animal health, with H7 subtypes causing outbreaks globally . In Mexico , highly pathogenic H7N3 viruses have circulated in poultry since 2012, causing sporadic human infections . Here we analyzed genetic markers in hemagglutinin sequences from Mexican H7N3 isolates and conducted serological assays on human populations with poultry exposure . Our results show conserved avian-like receptor binding sites , thus limiting human adaptation , alongside antigenic drift and acquisition of glycosylation sites likely driven by vaccination. Serological testing of 1103 individuals revealed no detectable antibodies against H7N3, indicating a naïve population . Phylogenetic analyses revealed multiple virus clades circulating regionally. These findings suggest that while current H7N3 viruses have limited capacity for sustained human transmission, the lack of population immunity underscores the importance of continued surveillan...

  {Excerpt} Influenza A H9N2 -- Hunan Province : - 1) A two-year-old boy with onset on September 28, 2025.  -- Jiangxi Province : - 2) A 70-year-old woman with onset on September 23, 2025.  (...) Source: Centre for Health Protection, Hong Kong PRC SAR,  https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk41.pdf ____

{Summary} -- During current epidemiological week , a rise in the West Nile Virus human cases has been observed although with reduced intensity compared most recent weeks.  -- Twenty-two new confirmed human cases have been reported during surveillance week from 2 to 8 October 2025.  -- The cumulative number of cases rose to 740  (they were 718 last week), of these:  - 354 were West Nile Neuroinvasive Disease (WNND): 16 in Piedmont, 53 Lombardy, 33 Veneto, 4 Friuli-Venezia Giulia, 1 Liguria, 30 Emilia-Romagna, 11 Tuscany, 1 Marche, 84 Latium, 2 Molise, 81 Campania, 2 Apulia, 2 Basilicata, 5 Calabria, 3 Sicily, 26 Sardinia, - 57 were asymptomatic cases in blood donors ,  - 318 were West Nile Fever cases , of which 1 imported from Kenya , 1 from Egypt and 1 from Maldives ,  - 4 asymptomatic cases,  - 7 unspecified cases.  -- Among confirmed cases there were 68 fatalities : 7 in Piedmont, 9 Lombardy, 2 Emilia-Romagna, 18 Latium, 28 Campania, 2 Cal...

  Abstract Viral diseases cause significant economic losses within the equine population. Horses are susceptible to equine coronavirus (ECoV) and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), although only ECoV has been associated to clinical disease . The aim of this study was to investigate, for the first time in Algeria , the seroprevalence of ECoV and SARS-CoV-2 antibodies and the prevalence of ECoV infection in horses . In 2022, a total of 299 serum samples was collected from horses aged 1 to 27 years . Serological analysis for the presence of ECoV and SARS-CoV-2 was performed using a validated in-house and a commercially available ELISA, respectively. In addition, fecal samples of these animals were tested for the presence of ECoV RNA by RT-qPCR . SARS-CoV-2-ELISA positive sera with high S/P ratios and negative samples close to the doubtful threshold were retested using a virus neutralization test ( VNT ). The seroprevalence of ECoV and SARS-CoV-2 in the teste...

  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 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 ____

  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...

  {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 ____

  {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)....

  ABSTRACT For over two decades, avian influenza virus (AIV) has significantly impacted the Egyptian poultry population , with multiple subtypes and genotypes contributing to significant economic and agricultural losses. As part of an ongoing national surveillance effort , this study aimed to monitor and genetically characterize AIV circulation across various poultry sectors in Egypt . Between 2022 and 2024, a total of 446,790 swab samples were collected, representing commercial farms (n = 25,057), backyard flocks (n = 403), and live bird markets “LBM” (n = 1250) to assess the prevalence and genetic diversity of circulating AIV strains. A total of 173 sampling units were found positive for high pathogenicity (HP) AIV H5 , including farms (n = 17), backyards (n = 11), and LBMs (n = 145). The HPAIV of H5N8 subtype was dominant (n = 75) over the H5N1 (n = 27) subtypes among all sectors and bird species ( chickens, ducks, turkeys ). Whole genome sequence analysis of positive H5 samples...

  Abstract Influenza A viruses (IAV) remain a persistent One Health threat, and whole-genome sequencing from wastewater offers a promising surveillance tool . However, IAV is at low abundance in wastewater , making it difficult to sequence. We benchmarked four targeted enrichment methods suited for whole-genome sequencing including custom and off-the-shelf amplicon and probe-based methods. Our custom HA tiled-amplicon panel was sensitive, fast, and cost-effective, making it suitable for monitoring low-abundance seasonal variants of known subtypes . However, its reliance on conserved and intact primer-binding sites limited primer design to fewer subtypes. A previously published universal amplicon method targeted all IAV subtypes , but it performed poorly in wastewater due to its reliance on intact genome segments. Probe-capture methods were resilient to RNA degradation and mismatches , potentially enabling broader surveillance and detection of emerging strains. However, probes were ...

  {Summary} Time Period: September 07, 2025 - September 13, 2025 -- H5 Detection :  3 sites ( 0.7% ) -- No Detection :  401 sites ( 99.3% ) -- No samples in last week :  57 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

  ABSTRACT H10 subtype avian influenza viruses primarily circulate among wild waterfowl but can occasionally infect mammals , including humans , and recent sporadic human cases have raised significant public health concerns . In this study, we sequenced and analysed 59 H10 subtype viruses isolated from wild birds in Taiwan . Results showed that all isolates were genetically distinct from human and other mammalian H10 subtype isolates. Taiwanese isolates exhibited high genetic diversity and could be categorized into 34 distinct genotypes , with each genotype circulating only in a single migratory season and not recurring during subsequent seasons. Additional analyses revealed that certain gene pools frequently circulate in the Pacific Rim , with evidence of North American lineage genes establishing long-term populations in Eurasia and vice versa. Although no characteristics indicative of mammalian adaptation was found in the Taiwanese isolates, temporal changes in the haemagglutinin...

  {Summary} -- During current epidemiological week ( 11– 17 September 2025),  65 new confirmed human cases of infection with West Nile Virus have been reported.  -- The total number of confirmed cases , since the beginning of the epidemic season, has thus risen to 647 (it was 582 last week), of these:  - 300 were West Nile Neuroinvasive Disease (WNND): 15 in Piedmont, 39 Lombardy, 24 Veneto, 2 Friuli-Venezia Giulia, 1 Liguria, 23 Emilia-Romagna, 5 Tuscany, 83 Latium, 2 Molise, 77 Campania, 2 Apulia, 2 Basilicata, 5 Calabria, 1 Sicily, 19 Sardinia,  - 54 were asymptomatic cases detected among blood donors ,  - 284 were West Nile Fever cases (one imported from Kenya),  - 3 asymptomatic cases and  - 6 unspecified casese.  -- Among confirmed cases, there were 47 death cases : 7 in Piedmont, 5 Lombardy, 1 Emilia-Romagna, 16 Latium, 15 Campania, 2 Calabria, 1 Sardinia.  - The Case-Fatality Rate in WNND cases was 15.8% (it was 20% in 2018 and...

  Situation at a glance Between 1 January and 29 August 2025, the International Health Regulations National Focal Point (IHR NFP) for Bangladesh notified WHO of four confirmed fatal Nipah virus (NiV) infection cases , temporally unrelated , reported from four different districts across three separated geographical divisions (Barisal, Dhaka, and Rajshahi) in Bangladesh.  NiV infection is a zoonotic disease transmitted to humans through infected animals (such as bats or pigs ), or food contaminated with saliva, urine , and excreta of infected animals .  It can also be transmitted directly from person to person through close contact with an infected person.  Fruit bats or flying foxes (Pteropus species) are the natural hosts for the virus.  Human NiV infection is an epidemic-prone disease that can cause severe disease in humans and animals, with a high mortality rate , and outbreaks primarily occurring in South and South-East Asia .  Since the first recognized...