ETIDIOH - NEW

  For immediate release: November 14, 2025   (25-138) First detection of this strain in a human, risk to the public remains low Contact: DOH Communications A Grays Harbor resident who was hospitalized with influenza symptoms in early November has been confirmed to have influenza A H5 , a type of avian influenza.  Additional testing shows the virus to be H5N5, an avian influenza virus that has previously been reported in animals but never before in humans .  The Centers for Disease Control and Prevention (CDC) and DOH currently consider the risk to the public from avian influenza to be low. The person is an older adult with underlying health conditions and remains hospitalized.  The affected person has a mixed backyard flock of domestic poultry at home that had exposure to wild birds .  The domestic poultry or wild birds are the most likely source of virus exposure; however, public health investigation is ongoing .  The Washington State Department ...

  {Excerpt} National situation summary Person-to-person spread :  None -- There is no known person-to-person spread at this time. Current public health risk :  Low -- The current public health risk is Low. Cases in the U.S. :  71 cases Deaths in U.S. :  1 death (...) Situation summary of confirmed and probable human cases since 2024 {Confirmed Cases}:  -- National: Total Cases: 71 {+1} [Cases - Exposure Source] -- 41 - Dairy Herds (Cattle){*} -- 24 - Poultry Farms and Culling Operations{*} -- 3 - Other Animal Exposure{†} -- 3 - Exposure Source Unknown{‡} {Probable Cases}:  -- National: Total Cases: 7 [Cases - Exposure Source] -- 1 - Dairy Herds (Cattle){*} -- 5 - Poultry Farms and Culling Operations{*} -- 0 - Other Animal Exposure{†} -- 1 - Exposure Source Unknown{‡} NOTE : One additional case was previously detected in a poultry worker in Colorado in 2022. Louisiana reported the first H5 bird flu death in the U.S. {*} Exposure Associated with Comm...

Human Avian Influenza Cases in Washington State Residents {*} [Exposure - Probable - Confirmed - Total human cases (H5)] -- Poultry - 3 - 11 - 14 -- Unknown - 1{^} - 0 - 1 -- Total - 15 {*} Washington residency could not be confirmed for one case with exposure to poultry in Washington. {^} Currently under investigation; case classification and source of infection may be updated. Note : Updates to national public health reporting and notification of novel influenza A infections were approved by the Council of State and Territorial Epidemiologists (CSTE) in June 2024 and enacted in September 2024. Whether a case is counted as confirmed or probable is determined after completion of a public health case investigation and takes into account a person's exposure to avian influenza virus, whether confirmatory testing at the CDC was negative or positive, and whether a person experienced symptoms of illness. The specific criteria used to determine if a case is confirmed, or probable is based...

For immediate release: November 13, 2025   (25-136) Contact: DOH Communications If confirmed, this would be the first human case of avian influenza reported in Washington in 2025 OLYMPIA – A Grays Harbor County resident has tested preliminarily positive for avian influenza, also known as bird flu . Confirmatory testing through the Washington State Public Health Laboratories is pending. Health officials are working to determine the potential sources of the infection , including contact with wild or domestic birds .  The person, who is an older adult with underlying health conditions, developed a high fever, confusion, and respiratory distress and was hospitalized in early November.  They are currently receiving treatment in King County after previously being treated in Thurston and Grays Harbor counties. Public health disease experts have not identified any risk to the public . The Washington State Department of Health is working with the local health departments and ...

  Abstract Highly pathogenic avian influenza virus H5N1 has been infecting dairy herds in the U.S. since its initial incursion into cows in early 2024 . Although national strategies have aimed to detect affected herds , the best way to surveil herds for the H5N1 virus has not been formally studied and we also do not understand herd-level patterns of infection . To understand infection patterns of H5N1 in dairy herds over time, we conducted early surveillance of non-affected farms in California in the Fall of 2024 in an observational study. Daily bulk tank milk (BTM) samples were submitted from each herd and tested for influenza A (IAV) via rRt-PCR. In a subset of herds, IAV testing of multiple excretion types from cattle of different classes and pen-level daily milk was also completed soon after BTM detection. Daily detections of IAV occurred in BTM for a minimum of 33 days , with some herds continuing to have detection beyond a 75-day window. BTM Ct nadirs were seen between 1-3 we...

  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% (...

  Abstract Since March 2024, HPAI H5N1 virus has infected dairy cattle in the U.S., prompting concern about novel transmission routes . During an outbreak in California , HPAI H5N1 RNA was detected in an asymptomatic bull's semen . Although infectious virus was not isolated , questions remain about semen-associated transmission risks and biosecurity practices. Competing Interest Statement The authors have declared no competing interest. Source: BioRxIV,  https://www.biorxiv.org/content/10.1101/2025.10.16.682947v1 ____

  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 Background Amid the declining clinical severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and diminishing public uptake of annual coronavirus disease 2019 (Covid-19) vaccines, contemporary evidence on vaccine effectiveness against clinically relevant outcomes is needed. Methods We conducted an observational study that used the electronic health records of the Department of Veterans Affairs to evaluate the effectiveness of the 2024–2025 Covid-19 vaccine among veterans who received the Covid-19 and influenza vaccines on the same day (164,132 participants) and in an active-comparator group of veterans who received the influenza vaccine only (131,839 participants), between September 3 and December 31, 2024. Participants were followed for 180 days or until the occurrence of an outcome, whichever came first. We used inverse-probability–weighted models to estimate vaccine effectiveness (calculated as 1 minus the risk ratio) against Covid-19–assoc...

  {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 -- What is already known about this topic? -  Influenza-associated encephalopathy (IAE) is a rare, severe neurologic complication of influenza. -- What is added by this report? - During the high-severity 2024–25 influenza season, 109 U.S. pediatric IAE cases were identified; 55% of affected children were previously healthy . Thirty-seven IAE cases were subcategorized as acute necrotizing encephalopathy (ANE), a severe form of IAE characterized by rapid neurologic decline and a poor prognosis . Overall, 74% of IAE patients were admitted to an intensive care unit , and 19% died ; 41% of ANE patients died. Only 16% of vaccine-eligible IAE patients had received the 2024–25 influenza vaccine. -- What are the implications for public health practice? - All children are at risk for severe neurologic complications of influenza . Annual influenza vaccination is recommended for all children aged ≥6 months to prevent influenza and associated complications, potentially including ...

  The World Health Organization (WHO) emphasizes that there is currently no conclusive scientific evidence confirming a possible link between autism and use of acetaminophen (also known as paracetamol) during pregnancy.  Globally, nearly 62 million people (1 in 127) have autism spectrum disorder , a diverse group of conditions related to development of the brain . Although awareness and diagnosis have improved in recent years, the exact causes of autism have not been established , and it is understood there are multiple factors that can be involved.   Extensive research has been undertaken over the past decade, including large-scale studies, looking into links between acetaminophen use during pregnancy and autism . At this time, no consistent association has been established.  WHO recommends that all women continue to follow advice of their doctors or health workers, who can help assess individual circumstances and recommend necessary medicines. Any medicine sh...

  {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 ____

  {Summary} Time Period: August 31, 2025 - September 06, 2025 -- H5 Detection :  4 sites ( 0.9% ) -- No Detection :  418 sites ( 99.1% ) -- No samples in last week :  43 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

{Summary} Time Period: August 24, 2025 - August 30, 2025 -- H5 Detection :  3 sites ( 0.7% ) -- No Detection :  428 sites ( 99.3% ) -- No samples in last week :  31 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

  Summary -- What is already known about this topic? - As of January 1, 2025, 37 human cases of highly pathogenic avian influenza (HPAI) A( H5N1 ) had been detected in California , none of which occurred in San Francisco. -- What is added by this report? - On January 9, 2025, a case of HPAI A(H5N1) infection was identified in a school-aged child in San Francisco through enhanced surveillance (influenza A virus subtyping of a sample of specimens weekly). No source of exposure was identified, and investigations found no laboratory evidence of human-to-human transmission among close contacts. -- What are the implications for public health practice? - Enhanced surveillance and timely subtyping of a subset of influenza A–positive specimens, including specimens from persons without known A(H5N1) exposure, are important to detect avian influenza A virus infections. Public health investigations are critical to monitoring for human-to-human transmission. Abstract In response to a highly pat...

  {Summary} Time Period: August 17, 2025 - August 23, 2025 -- H5 Detection :  2 sites ( 0.5% ) -- No Detection :  429 sites ( 99.5% ) -- No samples in last week :  31 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

  ABSTRACT Influenza A virus (IAV) in swine in the U.S. is surveilled to monitor genetic evolution to inform intervention efforts and aid pandemic preparedness . We describe data from the U.S. Department of Agriculture National Surveillance Plan for Influenza A Virus in Pigs from 2009 to 2022. Clinical respiratory cases were subtyped, followed by sequencing of hemagglutinin (HA) and neuraminidase (NA), and a subset of viruses was whole genome sequenced . Phylogenetic analysis identified geographic and temporal IAV reassortment hotspots . Regions acting as IAV genomic diversity sources or sinks were quantified, and dissemination was qualified and modeled. The dominant IAV clades were H1N2 (1B.2.1), H3N2 (1990.4.a), and H1N1 (H1-1A.3.3.3-c3). Internal genes were classified as triple-reassortant (T) or pandemic 2009 (P), and three genome constellations represented 73.5% of detections across the last 2 years. In some years, the distribution of IAV diversity was so narrow that it presen...

  Abstract Background :  Flaviviruses represent a significant worldwide threat to human health and have the potential to emerge and cause outbreaks in non-endemic geographical regions. Ongoing surveillance for these viruses in the United States–Mexican border communities such as El Paso, Texas , is lacking. As a continuing effort to better understand the prevalence and to determine which arboviruses are endemic, the aim of this study was to determine the prevalence rate of specific flavivirus antibody among 910 human umbilical cord blood samples obtained from mothers who delivered newborns in El Paso, Texas. Materials and Methods :  The samples were screened for West Nile virus (WNV) and dengue virus (DENV) IgG antibodies with an enzyme-linked immunosorbent assay and confirmed by a plaque reduction neutralization test for DENV, WNV, Zika virus (ZIKV) and Saint Louis encephalitis virus (SLEV). Results :  Among the 910 samples , 2% were positive for specific IgG antibo...

  {Summary} Time Period: August 10, 2025 - August 16, 2025 -- H5 Detection :  1 site ( 0.2% ) -- No Detection :  422 sites ( 99.8% ) -- No samples in last week :  37 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/nwss/rv/wwd-h5.html ____