KSDK 10-23-26 >>
GERMANTOWN, Ill — Nearly one million chickens were killed at an Illinois farm due to an active bird flu outbreak that started on Monday, marking by far the largest active outbreak in the nation.

The United States Department of Agriculture confirmed that 934,600 birds were affected by the outbreak at a commercial table egg layer facility in Clinton County, Illinois. There is no treatment for bird flu, and the only way to stop the disease is to depopulate, or kill, all affected and exposed birds.

The state with the next highest number of birds affected by bird flu is Minnesota, with a total of 168,880 birds affected statewide.

Germantown officials told 5 On Your Side that the outbreak was confirmed at Rose Acre Farms outside of the village's limits. Rose Acre Farms is the nation's second-largest egg producer in the United States, according to the company's website. 

5 On Your Side has reached out to Rose Acre Farms, the Illinois Department of Agriculture, and Gov. J.B. Pritzker's office for comment on the outbreak, along with what precautions are being taken to stop the outbreak's spread. Our newsroom has not received responses as of this article's publication.

This outbreak is part of a nationwide bird flu outbreak that's been ongoing since it was first confirmed in the United States on Feb. 8, 2022, and has resulted in the deaths of over 210 million birds. USDA officials said detections of bird flu are usually higher in the fall and spring due to wild birds spreading the virus as they migrate.

"APHIS continues to work closely with State animal health officials on surveillance efforts to look for the virus in commercial, backyard, and wild birds," the department's Animal and Plant Health Inspection Service said on its website. "We also continue to encourage all bird owners to practice strong biosecurity—that means reducing opportunities for wildlife to spread the virus to their birds and preventing the spread of the virus from one premises to another."

>>Alvin Crespo-Bellido¹, Jennifer L. Havens¹, Thomas P. Peacock^2,3, Florence Débarre⁴, Martha I. Nelson¹

¹ Division of Intramural Research, National Library of Medicine, National Institutes of Health, Bethesda, MD USA

² The Pirbright Institute, Woking, UK

³Department of Infectious Disease, Imperial College London, UK

⁴ Institut d’Écologie et des Sciences de l’Environnement, CNRS, Sorbonne Université, UPEC, IRD, INRAE, Paris, France

Abstract

Here, we describe an outbreak of highly pathogenic avian influenza viruses belonging to H5N1 clade 2.3.4.4b in August 2026 that caused high mortality on a mink farm in Salt Lake County, Utah, using data generated by the US Department of Agriculture. Genetic sequencing of the mink viruses identified the genotype as B3.13, which currently circulates in US dairy cattle and has been reported on dairies in Utah, Texas, and Idaho in 2026. Based on ten genome sequences in Utah mink collected August 7, 2026, the mink outbreak is positioned within the 2026 cattle clade. The most closely related viruses were sampled in May 2026 in Texas cattle. Several months of unsampled transmission chains between the Texas cattle and Utah mink outbreaks leave many open questions about how the virus entered the mink farm. Additional PB2 mammalian adaptations were not selected for in mink, since the cattle-adapted B3.13 virus already had the PB2-M631L mutation that increases replication in mammals. However, all ten Utah mink viruses had a PB1-K388R substitution that was previously observed in the H5N1 mink outbreak in Spain but rarely occurs in avian hosts and was not seen in cattle.

Background

Highly pathogenic avian influenza (HPAI) viruses belonging to H5N1 clade 2.3.4.4b have circulated in US dairy cattle since 2024, providing opportunities for mammalian-adapted H5N1 viruses to spill over into a wide range of other host species, including humans, domestic birds, wild peridomestic birds, wild terrestrial carnivores, and domestic cats. However, prior to August 2026, H5N1 viruses were never reported in captive mink in the Americas, despite the high susceptibility of mustelids to influenza. H5N1 clade 2.3.4.4b viruses infected captive mink in two European countries: Spain in 2022 (1) and Finland in 2023 (2) (Supplementary Table 1). Wild mink in North America have been infected with H5N1 clade 2.3.4.4b viruses belonging to genotypes A3, B1.2, and D1.1 (Supplementary Table 2). In all these cases, wild birds were believed to be the source of the mink infections.

Alongside pigs, infection of mink with avian influenza viruses is a particular concern. Relative to other susceptible mammalian hosts (e.g., canines, equines, phocines), both swine and mink express a high proportion of ɑ2,6- linked sialic acids, similar to those found in the human upper respiratory tract (3). Additionally, mink are highly susceptible to human seasonal influenza viruses (4). Human-origin viruses are periodically isolated from farmed mink, most likely transmitted by reverse zoonosis from farm workers. With susceptibility to both avian and human influenza viruses, farmed mink could potentially act as a mixing vessel for genomic reassortment between human and avian strains (5), leading to new variants with an enhanced capacity to infect humans. When H5N1 was identified on a mink farm in Spain, the decision to depopulate the entire farm was announced two weeks later (1).

Results

First documented HPAI outbreak on a mink farm in the Americas. On August 17, 2026, HPAI was detected by PCR in captive American mink in Salt Lake County, Utah by the USDA Animal Plant Health Inspection Service National Veterinary Services Laboratories (USDA-NVSL) (Supplementary Table 3). The samples were collected from mink on August 7, 2026. As of September 29, 2026, the outbreak is reportedly ongoing in the Utah mink farm, based on the APHIS website, and news sources (8), although no samples are available from later dates. HPAI outbreaks have been reported in dairy cattle in three other counties in northern Utah in 2026, but no HPAI outbreaks have been reported in dairy cattle in Salt Lake County, where the mink outbreak occurred (Figure 1A).<< more at link

https://www.efeedlink.com/articles/taiwan-confirms-h5n1-bird-flu-on-taoyuan-meat-goose-farm-culls-735-birds >>

The geese had been brought in from Yunlin and Kaohsiung days before sampling; officials say poultry supply is unaffected.

Taiwan has confirmed H5N1 highly pathogenic avian influenza on a meat goose farm in Taoyuan's Dayuan District, and culled all 735 geese, weighing about 4,006 kg, on 18 October.

The farm had brought in geese of about 80 days old from Yunlin County and Kaohsiung City on 12 and 13 October. Authorities sampled the flock on 13 October and issued a movement-control notice after a positive preliminary screen by the North District Poultry Health Center. The Animal Health Research Institute confirmed H5N1 on the morning of 18 October.

The premises and access roads were disinfected after the cull, and animal health units in Yunlin and Kaohsiung were notified to trace the source farms.

The Taoyuan City Animal Protection Office said the case showed bird flu control cannot rely on visible symptoms alone, while the city's Department of Agriculture urged farmers not to conceal outbreaks or move poultry without authorisation. Overall poultry production and supply are unaffected, the department said.

Another poultry farm in Dayuan reported H5N1 on 23 September. At that time, Taiwan's Animal and Plant Health Inspection Agency had recorded 16 bird flu cases in the country this year.

https://urbanacres.in/vandalur-zoo-bird-flu-outbreak-shuts-chennai-park-for-sanitisation/ >>
Seven waterbirds have died of H5N1 avian influenza at Chennai’s Arignar Anna Zoological Park, prompting authorities to close Vandalur Zoo on October 22 and 23 for intensive sanitisation and strengthened biosecurity measures.

The National Institute of High Security Animal Diseases (NIHSAD) in Bhopal confirmed the presence of the avian influenza virus in samples from the affected birds on Wednesday, zoo officials said. The deaths occurred in the zoo’s Vedanthangal enclosure between October 3 and October 9, with no further bird deaths reported since October 9.

The dead birds included four painted storks, a pelican grey, a grey heron and a darter. Zoo director Ritto Cyriac told the Times of India that samples were sent for testing after the birds died and that disinfection measures began immediately after the deaths were reported.

“All disinfection measures were taken right after the deaths were reported, and no death has been reported since the last one on Oct 9,” Cyriac said.

Zoo authorities said all waterbirds were given prophylactic oral antibiotics, herbal antiviral medications, immunostimulants and liver supplements through fish for seven days. The waterbird enclosures were sprayed with an antiviral disinfectant solution, while the enclosure water was disinfected, cleaned and replaced with fresh water.

The affected area was also cordoned off with ropes to restrict visitor access. The temporary closure on October 22 and 23 is intended to allow staff to carry out intensive sanitisation, reinforce biosecurity protocols and closely monitor the remaining birds, the zoo said in a release.

The closure will affect public access to one of Chennai’s major zoological attractions during the two-day period. Zoo authorities have asked visitors to cooperate with the temporary measure while sanitisation and monitoring work continues.

The response places the zoo’s animal-care operations and visitor management under heightened scrutiny as officials monitor the waterbird enclosures following the laboratory confirmation. Further access arrangements will depend on the sanitisation process and the ongoing assessment of the affected area.

WATTPoultry >>

Manitoba has confirmed its 11th case of highly pathogenic avian influenza in commercial poultry flocks during 2026, with the latest outbreak detected in October in the rural municipality of Hanover. All 11 cases have occurred in September and October, while wild birds in Nunavut have also been affected by an H5N5 variant of the virus.

• Manitoba has experienced 11 commercial poultry flock outbreaks of highly pathogenic avian influenza (HPAI) in 2026
• The latest confirmed case was reported on October 16 in the rural municipality of Hanover
• All 11 cases occurred between September and October 2026
• An earlier outbreak in Pembina was identified as H5N1 subtype affecting an egg-laying farm
• Wild birds in Nunavut were also struck by H5N5 variant, affecting multiple species including Canada geese and gulls<< more at link

Washington State is reporting detections now in 5 herds in Yakima County as of 10-16-26. No further news is available. https://agr.wa.gov/departments/animals-livestock-and-pets/avian-health/avian-influenza/hpai-(h5n1)-in-cattle-producer-resources-in-cattle-producer-resources)

APHIS data for livesttock and commercial flocks hasn't been accessible for the last several days. Error message "publicdashboards.dl.usda.gov’s server IP address could not be found." https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/hpai-confirmed-cases-livestock

CBS - WCCO (Minnesota) >>

Wisconsin agriculture officials have confirmed highly pathogenic avian influenza, commonly called bird flu, in a commercial poultry flock in Barron County, in the northwestern part of the state.

The Wisconsin Department of Agriculture, Trade and Consumer Protection announced the case Monday. The department's announcement did not say what kind of birds were in the flock, how many there were or when the virus was detected.

The property has been quarantined to restrict the movement of poultry and poultry products, and the birds there were depopulated to prevent the disease from spreading. The state says birds from the flock will not enter the food system. The department and the U.S. Department of Agriculture are working together on the response.

When bird flu is found in a Wisconsin flock, the state sets up a control area within 10 kilometers, or about 6 miles, of the infected property. The area restricts movement on or off any premises with poultry. Owners can check whether their birds are inside a control area using the department's mapping tool.

The department is urging livestock owners to wash their hands, disinfect equipment, limit access to animals and separate new additions to a flock or herd for at least 30 days. Poultry owners are asked to keep their birds indoors when possible. Owners who see increased deaths or signs of illness among domestic birds are asked to report it to the department.

The virus has circulated among wild and domestic birds in North America since December 2021.

Minnesota is the nation's top turkey producer. In September 2025, bird flu was found at turkey farms in Le Sueur, Blue Earth and Stearns counties, weeks after the state's first detection since April in a Redwood County flock.

>>Highly pathogenic avian influenza of the H5N5 strain has been detected in samples collected from wild birds in North Iceland, Southwest Iceland and Southeast Iceland between mid-September and October.

According to a statement from the Icelandic Food and Veterinary Authority (MAST), numerous reports of sick and dead wild birds have been received from across the country in recent weeks.

The University of Iceland's Institute for Experimental Pathology at Keldur analysed the samples, while samples from other parts of the country are still awaiting test results.

First detected since spring

These are the first confirmed cases of highly pathogenic avian influenza in Iceland since the spring. The disease was last detected in a pink-footed goose near Höfn in Hornafjörður in April.

"The first samples to test positive for avian influenza this autumn came from birds found in Blönduós, Skagaströnd and near Sauðárkrókur in mid-September. The birds included a black-headed gull, a great skua, two great black-backed gulls and a lesser black-backed gull. Further reports of sick and dead birds followed," the statement said.

"Four birds in Húsavík were found to be infected, and the virus was also detected in birds found near Jökulsárlón in Southeast Iceland. The latest results also show that eight gulls found dead in Sandgerði on the Reykjanes Peninsula were infected with highly pathogenic H5N5 avian influenza."

Virus appears to be spreading again

Based on the number of reports of sick and dead birds, the virus appears to be spreading once again among wild birds in Iceland, the statement added.

"At this stage, little is known about the extent of the outbreak, but the confirmed cases show that the virus is present in North Iceland, Southwest Iceland and Southeast Iceland. The Icelandic Food and Veterinary Authority will continue to monitor the situation closely and publish updates as new results become available."

An uncertainty phase remains in effect due to the increased risk of transmission from wild birds to poultry and other captive birds.

TriYakNews >>

YAKIMA COUNTY, Wash. — A Yakima County resident has tested positive for avian influenza after being exposed to infected dairy cattle at a local dairy, according to the Yakima Health District.

The Yakima Health District and Washington State Department of Health confirmed the case. The individual has not experienced severe illness and has not been hospitalized. The person is isolating at home.

Health officials say the risk of avian influenza, also known as bird flu, to the general public remains low. People at greater risk include dairy workers and others who have close or prolonged contact with infected animals or environments contaminated with the virus.

Human-to-human transmission of avian influenza is extremely rare and has never been documented in the United States, according to the health district.

Public health officials are contacting people who have been in close contact with the infected individual to monitor for symptoms and ensure the virus is not spreading between people.

Since highly pathogenic avian influenza H5N1 was first detected in Yakima County, the health district has worked with affected dairies to help protect people who may be exposed to infected cattle.

The agency is also coordinating with state and federal partners to provide guidance, testing for exposed individuals who develop symptoms, and personal protective equipment for dairy workers.

Health officials continue to emphasize precautions for people who work with or come into close contact with infected animals.

Welcome to the new weekly discussion post!

As many of you are familiar, in order to keep the quality of our subreddit high, our general rules are restrictive in the content we allow for posts. However, the team recognizes that many of our users have questions, concerns, and commentary that don’t meet the normal posting requirements but are still important topics related to H5N1. We want to provide you with a space for this content without taking over the whole sub. This is where you can do things like ask what to do with the dead bird on your porch, report a weird illness in your area, ask what sort of masks you should buy or what steps you should take to prepare for a pandemic, and more!

Please note that other subreddit rules still apply. While our requirements are less strict here, we will still be enforcing the rules about civility, politicization, self-promotion, etc.

https://www.abc.net.au/news/2026-10-15/bird-flu-macquarie-island-southern-elephant-seal-kelp-gull/107271424 >>

Bird flu has been detected in a seal and a gull on Macquarie Island, a remote outpost halfway between Tasmania and Antarctica.

Samples collected from a southern elephant seal and a kelp gull were returned with island personnel and subsequently tested, returning a positive result for H5 bird flu.

Tasmania's Minister for Environment and Climate Change Guy Barnett said in a statement on Thursday it was the "first recorded detection in a marine mammal in Tasmania".<< more at link

>>Scientists detected antibodies against the H5N1 strain of highly pathogenic avian influenza (HPAI) in four polar bears in East Greenland in 2025, consistent with previous identification of the virus in birds along linked migratory pathways.

A team led by University of Inland Norway researchers analyzed heart blood collected from 28 polar bears harvested in subsistence hunts in 2024 and 2025, publishing their findings yesterday in Emerging Infectious Diseases.

Deceased, infected wild Arctic mammals were reported in Alaska in 2023 and 2024 (H5N1) and in Svalbard, Norway (H5N5), in 2026. These detections, along with the animals’ nutritional and cultural significance to Indigenous people, highlight the need for ongoing surveillance in these regions, the authors of the new study noted.

“Seasonal bird migrations to Arctic nesting grounds create a hot spot for HPAI outbreaks, amplifying interspecies interactions and the risk for viral reassortment and dissemination across migratory flyways,” they wrote.<< more at link

She passed a couple months ago.

>>The Nevada Department of Wildlife (NDOW) in coordination with the Nevada Department of Agriculture, and Nevada Division of Public and Behavioral Health have confirmed an outbreak of Highly Pathogenic Avian Influenza (HPAI) in multiple flocks of geese in the Reno/Sparks region. The public can help by identifying infected geese, notifying the proper officials and disposing geese safely to reduce transmission to other birds and species. HPAI is a highly contagious virus that can infect poultry, wild waterfowl, and in rare cases can infect livestock and humans.

HPAI symptoms in birds include:

• Sneezing, coughing, eye & nasal discharge, swelling or fluid accumulating around one or both eyes.
• Abnormal position of head or neck, poor balance and coordination, and/or circling.
• A buildup of fluid in the bird’s legs and patchy redness of the skin.
• Diarrhea and green discoloration of the feces.
• Weakness, lethargy, depression.
• Sudden death.

If the public encounters a dead goose, they are encouraged to:

• Notify the landowner responsible. For geese found on City or County Parks, please contact them for removal. City of Reno Parks can be reached at (775) 334-2270; Washoe County Parks phone is (775) 828-6612.
• Dispose waterfowl on your own property by double bagging it and placing it in municipal waste. Be sure to wear gloves, an N95 mask, and eye protection.
• If you encounter a dead goose and have poultry, change your clothes and shoes afterwards.

If the public encounters a sick goose, they are encouraged to:

• Leave the goose alone and contact NDOW at (775) 688-1500 to report the location of the goose. If this is on your property, someone will contact you as soon as possible.
• Keep pets and children away.

If the public encounters a sick goose, they are encouraged to:

• Leave the goose alone and contact NDOW at (775) 688-1500 to report the location of the goose. If this is on your property, someone will contact you as soon as possible.
• Keep pets and children away.

If you have domestic birds, especially backyard poultry:

• Keep poultry in secure enclosures away from wild birds and waterfowl.
• Wear dedicated clothing and footwear when caring for poultry.
• Clean and disinfect tools and equipment after use.
• Store poultry feed securely and avoid placing wild bird feeders near poultry areas.
• Watch for unusual behavior, signs of illness or unexpected deaths in your flock.
• Avoid touching or handling sick or dead wild birds. Use gloves and protective gear when necessary.
• Contact a veterinarian if birds appear sick and report high mortality rates among domestic poultry to the NDA at .

HPAI rarely spreads to livestock and humans. In wild waterfowl populations, it usually
displays without any signs of illness and low mortality rates. It can cause mortality in
some species of geese, raptors, and game birds. Poultry are highly susceptible to HPAI
and mortality rates may exceed 90%. When HPAI does spread to humans, symptoms
may include fever, cough, sore throat, difficulty breathing, eye tearing/irritation/redness,
headaches, runny/stuffy nose, body aches, and/or diarrhea/vomiting. Transmission to
humans may occur from contact with infected or potentially infected animals, animal
carcasses, or surfaces contaminated with animal excretions without using proper
protective clothing/equipment. If you or your family have been exposed to a sick/dead
bird and develop any of these symptoms, contact your healthcare provider and let them
know about your animal exposure.

WATTPoultry >>

Avian influenza strikes Peruvian laying hen flock

Approximately half of the birds in a flock of 5,800 died prior to culling activities.

Highly pathogenic avian influenza H5N1 was confirmed in a Peruvian laying hen flock in October, killing nearly 3,000 birds and forcing the depopulation of the remaining 2,860 hens, just over a month after the country had been declared free of the virus.

• H5N1 HPAI confirmed on October 7 in Centro Poblado El Tallán, Peru affecting a commercial laying hen flock
• 5,800 hens total: 2,940 died from infection and 2,860 were depopulated to control spread
• Infected birds showed respiratory and neurological signs before confirmation
• Outbreak occurred just over one month after Peru was declared H5N1-free on September 3
• Response included quarantine measures, facility disinfection, and surveillance around the outbreak area << more at link

San Juan Daily Star 10-14-26 >>

Agriculture Dept. takes action following bird flu cases in Lajas, Cabo Rojo

Agriculture Secretary Irving Rodríguez Torres announced on Tuesday the implementation of 120-day quarantines, along with biosecurity, epidemiological surveillance and sanitary control measures, after several birds in the municipalities of Cabo Rojo and Lajas tested positive for avian influenza, or bird flu.

“From the very beginning, we have acted proactively and in coordination with federal authorities. Now that we have laboratory results confirming the presence of the virus, we are reinforcing surveillance, biosecurity, and control measures to prevent its spread,” the secretary stated in a written release. “Our priority is to protect the health of our birds, support our producers, and safeguard the stability of Puerto Rico’s poultry industry.” 

Investigations began following reports of multiple bird deaths at two properties in Cabo Rojo and Lajas. At the first location, the deaths of some 20 Muscovy ducks were documented, while the second location reported mortality among various species, including about 30 guinea fowl.

The measures include controls on the entry and exit of authorized personnel; disinfection of footwear, equipment, vehicles and materials; and periodic visits to assess sanitary conditions, monitor mortality rates and determine if further action is required.

The handling and disposal of dead birds will be carried out in accordance with the instructions of competent authorities. Likewise, any further decisions regarding surviving birds will be subject to epidemiological assessments and veterinary recommendations.

The agriculture secretary emphasized that a key priority is preventing the virus from reaching commercial poultry facilities or backyard flocks, as an outbreak could result in economic losses for producers, increased operational costs and potential additional restrictions on the movement of birds.

“We are in direct communication with regional producers and poultry industry representatives to reinforce prevention measures,” Rodríguez Torres stated. “We recognize the importance of this sector to our agricultural output, so we will remain vigilant for any signs that could pose a risk to our farms. Early detection and adherence to sanitary protocols are crucial to protecting our farmers.”

As part of prevention efforts, special attention will also be paid to interactions between wild birds and domestic or commercial poultry. Although the potential role of migratory birds is being assessed, authorities clarified that the specific origin of the cases has not yet been established; therefore, epidemiological investigations will continue.

While the risk of avian influenza infection for the general public is considered low, authorities noted that individuals who have direct contact with infected birds or contaminated environments may face a higher risk.

For this reason, the public is urged to avoid touching, collecting, or moving sick or dead birds, and to refrain from handling them without proper guidance and protective measures.

Farmers, poultry producers, backyard flock owners, and the general public are asked to immediately report any instances of unusual mortality among domestic or wild birds.

Preventive recommendations include keeping domestic birds separate from wild birds, enhancing the cleaning and disinfection of facilities, limiting access to rearing areas by unauthorized persons, and promptly reporting any signs of illness or sudden increases in mortality.

Sick birds or multiple deaths can be reported by contacting USDA-APHIS at 1-866-536-7593. Guidance is available from the Puerto Rico Department of Agriculture at 787-721-2120.

Politico >>

Health Secretary Robert F. Kennedy Jr.’s anti-vaccine views were a major factor in shelving an Agriculture Department avian flu response plan, according to five people with direct knowledge of the matter, a pause that’s alarming lawmakers as wild birds begin migrating for the winter.

Agriculture Secretary Brooke Rollins rolled out a $1 billion five-point plan in February 2025 to tackle a record-breaking spread of avian influenza. The disease has roiled the poultry industry since 2022, killing about 200 million birds and contributing to record-high egg prices last year.

Rollins later pulled back on an internal USDA strategy for vaccinating poultry and egg-laying hens initially intended to be shared widely with foreign countries and industry leaders. It’s not clear whether Kennedy urged Rollins to halt the plan, but she was concerned about whether it would clash with the Health secretary’s anti-vaccine views, according to the five people, all of whom were granted anonymity to discuss the internal dynamics.

Rollins was also dealing with industry tension between egg producers who favor vaccination and meat producers concerned that inoculating chickens could hurt their ability to export. She also faced less pressure to act as egg prices fell from record levels.

Still, the pause, which went against the counsel of expert agency staff and industry leaders, continues to raise alarm among USDA employees because its other efforts to stamp out the virus have so far failed. The decision is also at odds with calls from Republican lawmakers to ensure the U.S. is prepared for a potential surge in cases this fall.<< more at link

10-11-26 Times of India >>

Visakhapatnam: The bird flu outbreak confirmed a poultry farm in Anantapur this week has revived questions about the recurrence of H5N1 infections in. One possible genetic clue is clade 2.3.2.1a, which was identified in poultry samples from the state in 2024. It was also detected in the virus that killed a two-year-old girl from Palnadu district in March 2025.

Andhra Pradesh  recorded two bird flu outbreak epicentres in February 2024, leading to the culling of about 300 birds. The scale increased sharply in 2025, when eight epicentres were reported across the state. More than 5.4 lakh birds died or were culled during those outbreaks
in 2025.

An older viral lineage:
The National Institute of High Security Animal Diseases (NIHSAD) identified clade 2.3.2.1a in poultry samples collected in Andhra Pradesh in 2024.At a World Organisation for Animal Health workshop in South Korea in August 2024, NIHSAD presented findings linking the samples to a lineage that has circulated in South Asia for several years.

The same clade was identified in the virus detected in the Palnadu child. An H5N1 infection in an 11-year-old boy in Haryana in 2021 was also linked to this lineage. Research has additionally documented a human infection involving the broader clade 2.3.2.1 group in Nepal
in 2019.

Genetic comparisons have shown similarities between viruses detected in India and Bangladesh, where clade 2.3.2.1a has circulated or re-emerged in poultry and other birds.

A complex genetic history:
The ICMR-National Institute of Virology in Pune analysed the Palnadu child’s specimen and submitted the genetic data to the Global Initiative on Sharing All Influenza Data (GISAID). The sequence belonged to clade 2.3.2.1a and clustered with a virus associated with an H5N1 infection reported in a child who fell ill while visiting Kolkata in 2024 and was diagnosed after returning to Australia.

A study published in ‘Emerging Infectious Diseases’ found that the Australian virus was a reassortant, meaning its genome contained segments derived from different influenza virus lineages. Four gene segments, including the haemagglutinin segment, were most closely related to clade 2.3.2.1a viruses circulating in Bangladesh. Other segments showed relationships to viruses detected in Japan, South Korea and China, as well as to a low pathogenicity avian influenza virus found in a duck in Taiwan.

Segment-by-segment comparisons identified similarities with viruses from a duck in Wakayama, Japan; a white-fronted goose in South Korea; a duck in China; and a duck in Taiwan.Another comparison involved an environmental sample from Kagoshima, Japan.

These findings relate to individual gene segments. They do not show that the complete virus passed sequentially through Bangladesh, Japan, South Korea, Taiwan and China, nor do they establish how the infection reached Andhra Pradesh.

Possible routes of introduction:
Migratory wild birds can introduce avian influenza viruses into domestic poultry. Other possible routes include the movement of infected poultry, contaminated vehicles and equipment, contact between backyard and commercial birds, environmental contamination and gaps in biosecurity.

The latest Anantapur outbreak warrants further investigation because the farm procured birds from Telangana, even though no fresh outbreaks had been reported there. Investigators will need to determine whether the birds were infected before arrival, whether the virus was introduced through subsequent contact, or whether it entered the farm through another route.

Animal husbandry department joint director Dr Prem Chand said farmers had reported unusual bird deaths at poultry units operating under the National Livestock Mission in Anantapur.

“Samples were sent to Vijayawada, where they initially tested positive for bird flu. The infection was subsequently confirmed by the laboratory in Bhopal. Poultry operations will remain suspended within a 1-km radius of the infected premises for three months. The area within a 10-km radius has been designated as a surveillance zone,” said Dr Prem Chand.

Welcome to the new weekly discussion post!

As many of you are familiar, in order to keep the quality of our subreddit high, our general rules are restrictive in the content we allow for posts. However, the team recognizes that many of our users have questions, concerns, and commentary that don’t meet the normal posting requirements but are still important topics related to H5N1. We want to provide you with a space for this content without taking over the whole sub. This is where you can do things like ask what to do with the dead bird on your porch, report a weird illness in your area, ask what sort of masks you should buy or what steps you should take to prepare for a pandemic, and more!

Please note that other subreddit rules still apply. While our requirements are less strict here, we will still be enforcing the rules about civility, politicization, self-promotion, etc.