FluView Week 40: Antiviral Resistance Markers in H1N1 Over The Summer

 

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For the past 3 years we've been following scattered reports of `reduced susceptibility' of the seasonal H1N1 flu virus to the antiviral drug oseltamivir (aka `Tamiflu') around the globe. 

In March 2024 The Lancet Microbe published - Global Emergence of Neuraminidase Inhibitor-Resistant Influenza A(H1N1)pdm09 Viruses with I223V and S247N Mutations - which reported reduced oseltamivir inhibition among samples tested in Hong Kong in 2023.

Unlike the H275Y mutation - which caused nearly total resistance in an older (now extinct) strain of H1N1 back in 2008 - these viruses carried dual I223V/S247N mutations which together produced a modest ≈ 10-fold reduced inhibition by oseltamivir.

A concerning trend, but not nearly enough of a reduction to invalidate the use of the drug.  

Three months later (June 2024), the EID Journal: Multicountry Spread of Influenza A(H1N1)pdm09 Viruses with Reduced Oseltamivir Inhibition, May 2023–February 2024 reported a ≈ 13-fold reduced inhibition by oseltamivir. 

In July of 2025, Virus Research: A 15-year Study of Neuraminidase Mutations and the Increasing of S247N Mutation in Spain, we looked at a study that found a sharp increase in detections of the NA:S247N mutation beginning in 2024, but not combined with I223V.

Last December, in Eurosurveillance: Expansion of influenza A(H1N1)pdm09 NA:S247N Viruses with Reduced Susceptibility to Oseltamivir, Catalonia, Spain, and in Europe, July to October 2025. a Rapid Communications reported on another dramatic surge in H1N1 viruses carrying the NA:S247N mutation in Catalonia Spain, and other parts of Europe.

Abrupt rise in resistance in Catalonia, Spain - fall 2025

Some weeks (see above graphic), as many as 100% of viruses tested showed this NA:S247N mutation. The good news, however, was that once again a second synergistic mutation - NA:I223V - was not detected in these recent Catalonia isolates.

As for detections in the United States (see Feb 2026 blog), over the entire 2024-2025 flu season - out of 1697 H1N1 viruses tested - only one carried the NA-I223V and NA-S247N amino acid substitutions.

During the first 13 weeks of the 2025-2026 flu season (Oct - Dec) the CDC reported zero elevated resistance among the first 193 H1N1 viruses tested (see FluView Wk 53).  

But shortly after the New Year we began to seen an uptick in reduced inhibition detections in the United States. By late February (FluView week 7) - based on 517 H1N1 isolates tested since October - the CDC reported 10 isolates with reduced inhibition and 4 with highly reduced inhibition (due to NA:H275Y).

In early June we looked at the last full FluView report of the 2025-2026 flu season, which reported a total 20 reduced inhibition results, and 11 highly reduced results:

Nine A(H1N1)pdm09 viruses had NA-H275Y amino acid substitution conferring highly reduced inhibition by oseltamivir and peramivir. Nineteen A(H1N1)pdm09 viruses had amino acid substitutions NA-I223V and NA-S247N and showed reduced inhibition by oseltamivir. One A(H1N1)pdm09 virus had amino acid substitutions NA-I223T and NA-S247N and showed reduced inhibition by oseltamivir. Two A(H3N2) viruses had amino acid substitution NA-E119V conferring highly reduced inhibition by oseltamivir. Three B viruses had amino acid substitution NA-M464T and showed reduced inhibition by peramivir. 

While the number of S247N+I223V mutations remained relatively low (2.1%), this was more than a 35-fold increase over the previous year.  And equally concerning - after an extended absence - the tag team of S247N+I223V was being reported again in a newer (D.3.x) NA-clade H1N1 virus.

With the release last Friday of the first full FluView report since last May, we've our first look at the reported detections of the S247N+I223V amino acid substitution over the summer. 

While the overall numbers are low - and the lack of any reported H275Y mutations is reassuring - the percentage of H1N1 viruses that harbor the S247N+I223V mutation was nearly 50% higher (3.1%) than at the end of May (2.1%).

Viruses collected in the U.S. since May 24, 2026, were tested for antiviral susceptibility as follows:

Eight A(H1N1)pdm09 viruses had amino acid substitutions NA-I223V and NA-S247N and showed reduced inhibition by oseltamivir.

By way of comparison, over the summer of 2025 the CDC reported zero detections, and none were reported until early 2026.  

It still isn't clear how much of a public health impact these mutations will have - if any - going forward, but this week's FluView report provides a useful benchmark of where things stand as we enter into the 2026-2027 flu season.

Stay tuned. Things could get interesting. 

WHO DON: Middle East respiratory syndrome coronavirus - Kingdom of Saudi Arabia

Photo Credit NIAID

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While it doesn't get near the attention it did before COVID, MERS-CoV continues to circulate in dromedary camels in the Middle East, occasionally spills over into humans, and is likely under reported.   

MERS-CoV also continues to evolve, which raises concerns over its future impact (see Health Sci Rpts (Narrative Review): Pathogenicity and Potential Role of MERS-CoV in the Emergence of “Disease X”).

In 2025, the WHO released 3 MERS-CoV DON reports (see here, here, and here), and last December, France reported 2 Travelers Returning From Arabian Peninsula Diagnosed with the MERS-CoV virus.

This year has been somewhat quieter, with the first WHO update of 2026 published just last week (October 15th), which chronicles 8 cases reported by Saudi Arabia since last December.  

Of note - while the WHO states `Humans contract MERS-CoV through direct or indirect contact with dromedary camels, the virus’s natural host and zoonotic reservoir.' - 6 of the 8 cases reported no known contact with camels or camel products. 

This is not a new trend; in 2025 more than half of the cases reported by KSA listed no known contact with camels or camel products, and this has been frequently reported in the past.   

Exactly how these people are contracting the virus remains unclear.  

First some excerpts from the latest DON report, after which I'll have a postscript.

Middle East respiratory syndrome coronavirus - Kingdom of Saudi Arabia
15 October 2026

Situation at a glance

 Between 1 January and 5 October 2026, the Kingdom of Saudi Arabia reported eight laboratory-confirmed cases of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection, including one death. Cases were detected across six locations: Al Jouf (1), Arar (1), Hafr Al-Batin (1), Riyadh (2), Tabuk (1) and Taif (2). No epidemiological links were identified between any of the cases. All eight cases were symptomatic, most commonly presenting with fever (6/8), dyspnea (5/8), and cough (4/8). None were health and care workers. Infection was confirmed by RT-PCR testing. MERS is a zoonotic viral respiratory disease for which dromedary camels serve as the primary animal reservoir and two cases reported direct contact with camels while six reported no known camel exposure. Seven of eight cases had underlying comorbidities, recognized risk factors for severe MERS-CoV disease. The cases appear to represent sporadic infections related to zoonotic spillover rather than a single outbreak cluster.

Description of the situation

Between 1 January and 5 October 2026, a total of eight cases of MERS-CoV, including one death, was reported from six locations in the Kingdom of Saudi Arabia. Of the eight reported cases, five occurred among persons aged 70 years and older, two among adults aged 50–59 years, and one among an adult aged 30–39 years. Seven cases had underlying comorbidities, two reported direct camel contact, and one death was reported in an older adult (>65 year old) with comorbidities. There was no known epidemiological link identified among cases.

Case 1: A male aged 50–59 years, with comorbidities, from Al Jouf developed symptoms on 14 March 2026. He reported no known contact with camels or camel products. The patient was hospitalized on 17 March and laboratory confirmation of MERS-CoV infection was obtained by RT-PCR on 19 March.

Case 2: A male aged ≥70 years, with comorbidities, from Taif developed symptoms on 18 April 2026. He reported no known contact with camels or camel products. The patient was hospitalized on the same day, and laboratory confirmation was obtained on 22 April. He subsequently died as a result of the illness.

Case 3: A male aged ≥70 years, with comorbidities, from Hafr Al-Batin developed symptoms on 20 May 2026. He reported direct contact with camels. The patient was hospitalized on 26 May and laboratory confirmation was obtained on 27 May.

Case 4: A female aged ≥70 years, with comorbidities, from Riyadh developed symptoms on 31 July 2026. No known exposure to camels or camel products was reported. She was hospitalized on 3 August and laboratory confirmation was obtained on 8 August.

Case 5: A male aged 50–59 years, with comorbidities, from Tabuk developed symptoms on 20 August 2026. He reported no known contact with camels or camel products. He was hospitalized on 23 August and laboratory confirmation was obtained by RT-PCR on 24 August.

Case 6: A male aged 30–39 years, with no known comorbidities, from Riyadh developed symptoms on 14 August 2026. He reported no known contact with camels or camel products. He was hospitalized on 20 August and laboratory confirmation was obtained on 23 August.

Case 7: A male aged ≥70 years, with comorbidities, from Taif developed symptoms on 11 September 2026. He reported no known contact with camels or camel products. He was hospitalized on 17 September and laboratory confirmation was obtained on 19 September.

Case 8: A male aged 60–69 years, with comorbidities, from Arar developed symptoms on 20 September 2026. He reported direct contact with camels. He was hospitalized on 20 September and laboratory confirmation was obtained on 21 September.

        (SNIP)

WHO risk assessment

MERS is a zoonotic viral respiratory disease caused by MERS-CoV, for which dromedary camels serve as the primary animal reservoir. Human infection can range from asymptomatic or mild illness to severe disease and death. Human infections continue to occur through direct or indirect exposure to infected dromedaries or their products, while limited human-to-human transmission has been documented, primarily among close contacts and in healthcare settings. Sustained community transmission has not been observed. No licensed vaccine for MERS-CoV exists to date.

As of 5 October 2026, WHO had been notified of 2643 laboratory-confirmed MERS cases globally, including 965 deaths, since the virus was first identified in 2012. The majority of cases (84%; 2232 cases and 870 deaths) have been reported from Saudi Arabia. These figures likely underestimate the true number of infections since mild and asymptomatic cases may remain undetected/unreported, while the reported case fatality of ratio of 37% may overestimate mortality among infections.

Although the number of reported MERS cases has declined substantially since 2020, MERS-CoV continues to circulate in dromedary camel populations in the Middle East and African regions and continues to cause sporadic human infections. The observed decline in reported MERS cases, in particular during the COVID-19 pandemic emergency phase, is thought to be a result of pandemic-related IPC measures that also limited human-to-human transmission of MERS-CoV, as well as behavioral changes during the pandemic. Any role of potential cross-reactive immunity from SARS-CoV-2 infection and/ or vaccination remains in need of further investigation. Other hypotheses—such as reduced surveillance, viral attenuation, or decreased circulation in camel populations—are not supported by current evidence.

WHO expects additional sporadic MERS cases to occur in countries where the virus circulates in camels and anticipates that travel-associated exportation of cases will continue. Delays in detection remain possible due to the clinical presentation of MERS being similar with other respiratory infections, including influenza and COVID-19. Numerous outbreaks in KSA and the Republic of Korea have demonstrated that primary cases can result in substantial secondary transmission, particularly in healthcare settings and through importation of travel related cases.

The notification of the recent cases in Saudi Arabia does not change WHO's overall risk assessment - the risk remains moderate at both the regional and global levels, reflecting the continued occurrence of sporadic zoonotic infections, the potential for healthcare-associated outbreaks and international exportation of cases, in the absence of sustained human-to-human transmission.

WHO continues to monitor the epidemiological situation through routine surveillance and reporting under the International Health Regulations (IHR 2005) and conducts ongoing risk assessments using available epidemiological and virological information.

       (Continue . . . )

In June of 2025 we looked at an editorial in Journal of Epidemiology & Global Health on the importance of healthcare preparedness and surveillance (see Al-Tawfiq & Memish On Recurrent MERS-CoV Transmission in Saudi Arabia), with an emphasis on identifying asymptomatic carriers. 

Two months later we reviewed an IJID Editorial: Al-Tawfiq on Global Epidemiology and Public Health Challenges of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) - which looked again at what may be the most challenging aspect of MERS detection; asymptomatic or mildly symptomatic cases.

Although MERS-CoV clearly isn't ready for prime time, each new zoonotic spillover from camels - or cryptic transmission - is another opportunity for the virus to better adapt to a human host.  

Which is why we need better MERS-CoV surveillance and reporting, both in the Middle East, and in Africa (see EID Journal: Geographic Distribution of MERS-CoV among Dromedary Camels, Africa). 

Washington State Confirms 3rd Dairy Herd Infected With H5N1

 

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Since 2024 Washington State has seen scores of HPAI outbreaks in poultry, and more than a dozen confirmed and probable human infections related to exposure to poultry and/or wild birds. 

Eight days ago (Oct 9th), however, their WSDA confirmed their first detection of avian influenza in dairy cattle (herds=2). 

Yesterday, Washington State reported their first (reportedly mild) human infection with H5N1 derived from an (unspecified) dairy exposure.  

Details on this latest case remain scant, and yesterday's CDC FluView Report (wk 40) did not include this case, reporting: 

Novel Influenza A Virus Infections

No new confirmed human infections with a novel influenza virus were reported to CDC as of October 14, 2026.

The CDC's A(H5) Bird Flu: Current Situation webpage was updated on the 15th, showing the latest dairy-associated case (see below). Presumably we'll get an update in next week's FluView. 

In the meantime, the USDA has added a 3rd dairy herd from Washington State to their HPAI positive list.  Other than the one-line entry (below), I've seen no other information on this outbreak. 

Thus far, the genotype of the virus infecting Washington Cattle (likely either B3.13 or D1.1)  - and the recent human case - have not been announced, nor do we know exactly what kind of exposure the recent human case had. 

For more than 2 years the CDC, the USDA, and state agricultural agencies have urged the use of PPEs for farm workers, and anyone else who might be exposed to infected livestock or birds. 

While recommended, the use of PPEs has been suboptimal, particularly on farms and ranches. They can be hot, cumbersome to wear, and difficult to don and doff properly. (see MMWR: PPE Use by Dairy Farmworkers Exposed to Cows Infected with HPAI A(H5N1) Viruses — Colorado, 2024).

Over the past 30 days the number of infected backyard flocks vs. commercial flocks has run nearly 2 to 1, and over the course of the past 4+ years the number of backyard flock (n=1227) outbreaks have exceeded commercial outbreaks (n=1048). 

Although the risks of infection are believed low, we've already seen at least two fatalities (here, and here) in the United States from H5Nx following `. . . exposure to a combination of a non-commercial backyard flock and wild birds.' 

The APPA estimates `Eleven (11) million U.S. households own backyard chickens (a 28% increase from 2023)', yet a recent survey (see MMWR: Knowledge, Attitudes, and Practices Regarding Avian Influenza Among Owners of Backyard Flocks) found significant gaps in their knowledge of dealing with avian flu. 

Although it is too early to predict what kind of avian flu season we will see this fall and winter - or whether any new genotypes will be added to the mix - we are already seeing signs of increased activity.  

Which means, if you raise backyard birds, frequent live markets, or have outdoor pets, now would be a good time to familiarize yourselves with the risks of avian flu, and the things you can do to reduce those risks to you and your families.

UF/IFAS Extension: What Backyard Flock Owners Need to Know about Bird Flu (Influenza H5N1)

 

CDC Guidance on Bird Flu in Pets and Other Animals

 

Washington State Confirms Human Avian Flu Infection

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A week ago Washington state confirmed their first detection of avian influenza in dairy cattle, and overnight it was announced by the Yakima County Health District that a local resident who was exposed to infected dairy cows has tested positive for the virus.

There is still a lot we don't know about this case, hopefully the CDC will provide more details later today in their weekly FluView.   

The full press release follows.  I'll update this report as more information becomes available.

Yakima County Resident Tests Positive for Avian Influenza

We Are Public Health

Media Release

For immediate release: October 15, 2026

Contact: Stephanie Ruiz, Communications Specialist (509) 941-7364

Yakima County Resident Tests Positive for Avian Influenza

Yakima, WA- The Yakima Health District (YHD), in coordination with the Washington State Department of Health (DOH), is reporting a confirmed case of avian influenza in a Yakima County resident who was exposed to infected dairy cattle at a Yakima County dairy. The resident has not experienced severe illness or been hospitalized. The individual is isolating at home.

The risk of avian influenza infection 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. Transmission of avian influenza between humans is extremely rare and has never been documented in the United States. To ensure that human-to-human spread is not occurring, public health officials are contacting anyone who has been in close contact with the patient to monitor for symptoms.

Since the initial detection of Highly Pathogenic Avian Influenza (HPAI) H5N1 in Yakima County, YHD has been in contact with the impacted dairies to protect the health of people who may be exposed to infected cattle.

YHD continues to coordinate with state and federal public health partners to provide guidance and resources to help protect exposed individuals. This includes providing tests for exposed individuals who develop symptoms to support prompt diagnosis and appropriate medical care. YHD is working with partners to connect affected dairies with appropriate personal protective equipment (PPE) for their workers.
About Avian Influenza

Avian influenza, commonly called bird flu, is caused by influenza viruses that primarily circulate among wild birds but can also infect other animals, including poultry and dairy cattle. On rare occasions, these viruses infect people and cause illness.

Most human infections with avian influenza have occurred following close or prolonged contact with infected animals or environments contaminated with the virus. People can become infected when virus enters their eyes, nose, or mouth. The severity of illness can range from mild to serious and potentially life-threatening.

Public Health Recommendations

The risk of avian influenza infection to the general public is low. However, people who work with or have contact with potentially infected animals are at higher risk and should follow workplace safety guidance and use recommended personal protective equipment. Residents should avoid touching sick or dead animals, animal waste, and surfaces that may be contaminated.

Pasteurized milk and dairy products remain safe to consume. Pasteurization inactivates avian influenza virus and other harmful pathogens. People should avoid raw milk and unpasteurized dairy products because they may contain harmful germs, including avian influenza. Do not feed pets raw milk, unpasteurized dairy products, or raw meat, including raw pet foods.

It is especially important that people who may have exposure to sick animals get a seasonal flu vaccine. While the seasonal flu vaccine will not prevent bird flu infection, it reduces the risk of becoming sick with both human and avian influenza viruses at the same time. Seasonal flu vaccine is recommended for everyone six months and older.

Symptoms of avian influenza in people can include eye redness or irritation, fever or feeling feverish, cough, sore throat, runny or stuffy nose, muscle or body aches, headache, and fatigue. More severe illness can occur.

If you work on a dairy farm and develop symptoms after potential exposure to infected cattle, contact your healthcare provider or the Yakima Health District at (509) 249-6541.
Reporting Sick or Dead Animals

Domestic Birds:Report sick/dead domestic birds using the online form, or call the Washington State Department of Agriculture’s Avian Health Program: 1-800-606-3056. Visit Avian Influenza | Washington State Department of Agriculture for more information about how to protect backyard flocks.

Wild Birds:Use an online form to report sick/dead wild birds suspected of avian influenza to the Washington Department of Fish & Wildlife.

Livestock: To report sick livestock, isolate affected animals and contact your veterinarian and WSDA at 360-902-1878 or email ahealth@agr.wa.gov.

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“We are working closely with our public health partners to follow up with people who have been in close contact with this individual. We want to make sure they know what symptoms to watch for and can access testing and treatment if needed.” -Dr. Dave Atteberry, Health Officer, Yakima Health District 

Australia: H5 Bird Flu Reported on Macquarie Island

 
Macquarie Island - Credit Wikipedia

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Six weeks ago Australia announced they would soon be withdrawing their research team from remote Macquarie Island - located about halfway between Australia and Antarctica - over concerns that bird flu would arrive and decimate that island's wildlife much as it did on Heard Island last year. 

Citing `psychosocial risks' to personnel who were stationed there, DCCEEW decided to temporarily extract all personnel from the research station.

Today, Guy Barnett, Tasmanian Minister for Environment and Climate Change, announced that the evacuated research team brought back with them samples from the island which have tested positive for H5 bird flu.

15 October 2026

Guy Barnett, Minister for Environment and Climate Change

H5 bird flu has been detected in a Southern elephant seal and a kelp gull on Macquarie Island.

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

This is the first recorded detection in a marine mammal in Tasmania.

As bird flu continues to be detected in Tasmania, members of the public are encouraged to continue reporting sick or dead birds. Reports play an important role in helping authorities detect and respond to potential cases.

Avoid contact with sick or dead birds and report sightings through https://nre.tas.gov.au/reportbirdflu or by calling the Emergency Animal Disease Hotline on 1800 675 888.

The Department of Natural Resources and Environment Tasmania provides regular public updates through media releases. The latest testing and surveillance figures are updated on the department's website.

More information is available at www.nre.tas.gov.au/BirdFlu.

While there are no reports of mass casualties on Macquarie Island, four months ago, in Preprint: Mass mortality of southern elephant seals during multi-species outbreak of HPAI H5N1 on sub-Antarctic Heard Island, we saw that the carnage from the Heard Island outbreak was worse than originally feared, with 76% mortality among Elephant Seal pups.

Meanwhile, Australia's bird flu count continues to rise, with the latest figure showing more than 700 confirmed events, and in excess of 63,000 hotline reports by the public. 

 

Nevada Dept of Wildlife Warns on HPAI in Multiple Flocks of Wild Geese

 
Credit Wikipedia

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We've a press release from Nevada's Department of Wildlife (NDOW) - posted late yesterday - warning the public that `multiple flocks' of wild geese in the Reno/Sparks region have tested positive for HPAI.

While there aren't a lot of specifics offered in this statement (precisely where, how many flocks, which subtype and/or genotype, etc.), they are urging the public to be careful around sick or dead birds, and how to report any findings. 

Local media, for now, are repeating the NDOW announcement, and adding little additional detail. First, the Nevada announcement, after which I'll have a bit more.

Nevada State Agencies Respond To Bird Flu Outbreak In Geese

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 diseasereporting@agri.nv.gov.

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.

Since H5Nx established itself in North America in 2021-2022, each fall we've seen an increase in HPAI as southbound migratory birds leave their high latitude roosting areas for warmer climes.

The $64 question (see 2025's H5Nx: Reassort & Repeat) is whether this year's bird flu will be a repeat of last year's strain (predominantly D1.1), or whether new genotypes have emerged. It can sometimes takes months before that question can be answered. 

Although this advisory is specifically for the Reno/Sparks area, HPAI can turn up just about anywhere in North America this time of year.  

Which means, if you raise backyard birds, frequent live markets, or have outdoor pets, now is a good time to familiarize yourselves with the risks of avian flu, and the things you can do to reduce those risks.

UF/IFAS Extension: What Backyard Flock Owners Need to Know about Bird Flu (Influenza H5N1)

 

CDC Guidance on Bird Flu in Pets and Other Animals