Migratory routes, bird flu and Clade 2.3.4.4b H5N1 virus

 

Map:  Audubon 

Headline:  Down to Earth, 4/17/2026

Himanshu Nitnaware reports:

A new reassortant highly pathogenic genotype of the avian influenza (HPAI) A(H5N1), commonly known as bird flu, has rapidly spread across the US and Canada, underlining the need for pandemic preparedness. 

Clade 2.3.4.4b H5N1 virus, which emerged in late 2021, has affected more than 485 bird species and 48 mammal species worldwide. Now, a new study published in Nature Communications highlights that the new reassortant of genotype D1.1 nearly replaced clade 2.3.4.4b in North America by late 2024. 

This genotype was found during the fall migration season of 2024, in September, and was mapped using active and passive methods of avian influenza surveillance across the United States and Canada.

 

Related posts:

April 16-20

Saskatchewan and South Dakota report new cases of bird flu.  (4/16)

 

April 11-15:

New York bird flu news:  Hofstra University students are seeing lot of dead and dying birds on campus,  (4/15)

China reports 2 more cases of avian flu in humans.  (4/14)

Germany, Spain, and Poland report additional cases of Newcastle disease

Arkansas reports 1st case of bird flu in 2026.  (4/14)

First human case of avian influenza reported in the European Union (Italy).  (4/13)

Singapore reports Newcastle Disease in poultry flock.  (4/13)

RSPB Bird and Wildlife Conservation Charity in United Kingdom recommends taking down bird feeders this summer.  (4/11)

2026 bird flu tally in Indiana reaches 40 cases.  (4/11)

April 6-10:  

Case of bird flu in red fox reported in Nome Alaska.  (4/10)

Bird flu is ravaging urban wildlife in New York.  (4/9)

Even the 1% have to deal with bird flu  (The Hamptons Long Island edition).  (4/9)

The sky above Pennsylvania is a bird flu spreading superhighway .  (4/7)

Since March 18th, bird flu has hit 23 farms in Nepal.  (4/7)

Indiana has reported 39 cases of bird flu so far this year (96 days).  (4/7)

April 1-5

In Japan, 30% of bird flu cases this winter are at sites where there was a previous infection.  (4/4)

2 bird flu cases in South Dakota and 1 in Indiana bring U.S. 2022-2026 tally to 1,001 flocks.  (4/4/)

Preparedness, not luck, is the proper bird flu strategy.  (4/3)

Scotland bird flu news:  Bass Rock gannet population falls by almost a third since bird flu outbreak. (4/3)

Bird flu detected in sea lion in Morro Bay California.  (4/3)

First bird flu and now a war in Iran, poultry producers face a double whammy.  (4/3)

Raising poultry is a treacherous business nowadays.  (4/1)

Germany and Poland report multiple cases of Newcastle disease in poultry.  (4/1)

Wisconsin bird flu news:  Depopulation of chickens leads to layoffs at two Daybreak Foods facilities.  (4/1)  

Lancaster County Pennsylvania reports yet another case of bird flu. (4/1

March 26-31:

Indiana continues to be ground zero for bird flu outbreaks.  (3/31)

South Korea has reported 60 cases of bird flu so far in 2026.  (3/31)

Bird flu re-emerges in Nepal .  (3/31)

Mapping bird flu's worldwide hotspots.  (3/30)

University of Michigan joins research on infectivity of bird flu in the air.  (3/28)

Moving toward acceptance of new bird flu reality.  (3/28)

Connecticut reports dead geese from bird flu all over the state.  (3/27)

Bird flu in New Jersey impacts number of live eagles nests.  (3/27)

Since 2022 Pennsylvania has tallied 480 cases of bird flu affecting 16,000,000 domesticated birds.  (3/27)

In one day, Indiana boosts its year-to-date tally of bird flu cases to 32.  (3/27)

Indiana boosts its year-to-date tally of bird flu cases to 29.  (3/26)

March 21-25:

Skagit County Washington reports its first case of bird flu.  (3/25)

Jefferson County Wisconsin experiences residual effect of bird flu:  Thousands of gallons of spilled wastewater.  (3/24)

And the bird flu hits just keep on comin' in Indiana this month.  (3/25)

West Virginia reports case of bird flu in backyard chickens.  (3/24)

Indiana reports two more cases of bird flu bringing its tally to 26 so far this year.  (3/24)

Danger, Will Robinson!!  It's spring migration time and bird flu is raging.  (3/23)

Bird flu ravages marine mammals, raising alarm around the world.  (3/23)

Three more cases of bird flu reported in Indiana.  (3/23)

Crash leaves dead ducks from bird flu looking like road kill in Indiana.  (3/21)

March 16-20:

Spring migration ramps up the likelihood of widespread bird flu outbreaks.  (3/20)

Northeast Indiana continues to be hot spot for bird flu.  (3/20)

Bird flu wipes out 850,000 egg-laying hens in Lancaster County, Pennsylvania.  (3/20)

Pennsylvania reports 28th case of bird flu so far this season.  (3/19)

Bird flu carnage continues at Ano Nuevo State Park in California.  (3/18)

Circulation of avian flu in wild birds endangers Europe's commercial poultry flocks.  (3/18)

Sounds like Wisconsin Republicans want to sell public lands to CAFOs to bury millions of chickens infected with bird flu.  (3/17)

New cases of bird flu reported in Maryland, Michigan and Indiana.  (3/17)

March 11-15, 2025

Wisconsin bird flu update:  3 million dead chickens composting in your neighborhood is not a pleasant experience.  (3/15)

Bird flu outbreak on California coast has spread from elephant seals to other marine mammals.  (3/14)

Wisconsin puts poultry shows and exhibitions on hold in 20 southern counties due to recent bird flu outbreak.  (3/14)

Indiana reports four more cases of bird flu.  (3/13)

Geese go to New Jersey and die of bird flu.  (3/11)

March 6-10, 2026.  

Argentina reports cases of bird flu in commercial and backyard flocks.  (3/10)

More bird flu cases in Illinois and Pennsylvania.  (3/10)

Bird flu hit another turkey farm in Illinois.  (3/9)

3.1 million chickens zapped by bird flu at two CAFOs in southeast Wisconsin.  (3/6)

Center for Infectious Disease Research  Policy Research (CIDRAP) at University of Minnesota bird flu dashboard.  (3/6)

Bird flu on the rise in Utah.  (3/6)

23,000 pheasants depopulated in United Kingdom as result of bird flu outbreak.  (3/6)

Iowa reports 4 cases of bird flu in backyard flocks in 2 weeks.  (3/6)

Illinois reports first case of bird flu since March 2025.  (3/6)

March 1-5, 2026

Backyard case of bird flu reported in Dane County Wisconsin.  (3/5)

More dead geese from bird flu in New Jersey.  (3/5)

Iowa reports 5th and 6th cases of bird flu in 2026.  (3/5)

Bird flu cases reported in North Carolina.  (3/4)

Indiscriminate scavenging puts black vultures at risk of bird flu.  (3/3)

Delaware reports second case of bird flu in Kent County.  (3/3)

Two cases of bird flu reported in LaGrange County Indiana.  (3/3)

Bird flu outbreak reported in Daviess County Indiana.  (3/2)

Bird flu wipes out wild birds in New Jersey. (3/2)

Bird flu wiping out geese in the Hamptons on Long Island.  (3/2)

Lancaster County Pennsylvania is ground zero for this winter's bird flu outbreaks.  (3/1)

February 20-28,2026

South Korea gets the lede in article about bird flu cases in Asia.  (2/28)

Bird flu knocks California seal watching tours off the schedule.  (2/28)

Bird flu most likely cause of death of 101 vultures in Florida state park.  (2/27)

Outbreak of bird flu in California threatens thousands of elephant seals.  (2/27)

Bird flu cases reported in Pennsylvania, South Dakota, and Kansas.  (2/27)

Maryland reports 3rd case of bird flu in 2026.  (2/27)

California reports cases of bird flu in elephant seal pups.  (2/26)

Argentina reports first cases of bird flu in commercial operation since fall of 2025.  (2/25)

South Carolina reports its first case of bird flu at commercial operation since before 2022.  (2/25)

Ontario reports 1st Canadian bird flu outbreak in more than a month.  (2/24)

New cases of bird flu reported in 3 states.  (2/24)

Bird flu likely cause of death of 24 swans in London.  (2/23)

San Juan Island Washington reports that red foxes have tested positive for bird flu.  (2/23)

Japan reports 20th case of bird flu this season at farm with 560,000 egg-laying hens.  (2/22/2026)

SHOCKER!!  Dead birds found in Ohio gated community.  Bird flu suspected.  (2/21)

And the bird flu hits just keep on comin' for Lancaster County Pennsylvania.  (2/20)

Bird flu outbreak in New Jersey forces closure of park.  (2/20)

February 10-19, 2026

Since 2022, the egg industry has lost more than 150,000,000 birds.  (2/19)

'Unprecedented' outbreak of bird flu in ravaged Lancaster County Pennsylvania.  (2/18)

Boone County Indiana reports bird flu at commercial breeder turkey farm.  (2/18)

Folks are finding dead birds all over Long Island New York.  (2/18)

Geese aren't making it out of Jersey alive due to bird flu,  (2/18)

Warren Ohio area residents told to stay away from dead birds due to bird flu outbreak.  (2/17)

Duck flock hit with avian flu in Elkhart County, Indiana.  (2/17)

Commercial turkey flock in southwest Indiana hit with bird flu.  (2/17)

So far in 2026 Lancaster County Pennsylvania has recorded 2,400,000 cases of bird flu.  (2/16)

Bird flu hits wild birds throughout Utah.  (2/16)

Maryland reports 2nd case of bird flu in 2026.  (2/16)

Lancaster County Pennsylvania is currently ground zero for bird flu.  (2/13)

Dead skunk in Pueblo Colorado tests positive for bird flu.  (2/13)

Israel report 16 cases of Newcastle Disease since November 2025.  (2/12)

Bird flu hits Lancaster County Pennsylvania again.  (2/12)

Bird flu hits California broiler chicken farm.  (2/11)

Bird flu reported in numerous states in India.  (2/11)

Bird flu wipes out hundreds of crows in Terre Haute, Indiana.  (2/10)

First cases of bird flu death in Antarctica confirmed.  (2/10)

Bird flu makes a return engagement to Poland and Hungary.  (2/10)

February 1-9, 2026

Death by bird flu of crows in New York State. (2/8)

Bird flu reported in Mississippi, South Dakota, and Kansas.  (2/6)

Hundreds of dead geese found in lake in Ramson Canyon, Texas.  (2/5)

Second egg-laying facility in one week is hit with bird flu in Lancaster County, Pennsylvania.  (2/5)

Nigeria reports first case of bird flu in 3 years.  (2/4)

Georgia reports another case of bird flu.  (2/4)

South Korea egg supply diminished by bird flu outbreaks.  (2/3)

Bird flu reported at Pennsylvania egg laying facility with 1,500,000 hens.  (2/2)

January 21-31, 2026

Bird flu hits Colorado egg laying facility with 1,300,000 chickens.  (1/31)

Welcome to year 4 of bird flu.  (1/30)

Kossuth County Iowa report 2nd bird flu case in a week.  (1/30)

10 European countries report 78 cases of bird flu during first 4 weeks of 2026.  (1/30)

Five cases of bird flu reported in Long Island, New York.  (1/30)

Avian flu continues to infect wild birds in Orlando Florida area.  (1/30)

Georgia reports third case of bird flu in 2026.  (1/29)

Report:  Nitrogen provides calmer way to depopulate birds inflected with avian flu.  (1/29)

Bird flu die-off of about 500 Canadian geese reported in Manitoba.  (1/25)

Second case of bird flu reported in Walker County Georgia.  (1/25)

Indiana reports 2nd case of bird flu in 2026.  (1/25)

Flock of 3,000 ducks infected by bird flu in Indiana.  (1/23)

Iowa reports first case of bird flu in 2026 (7,000 pheasants and 120 chickens).  (1/23)

Swans and bird flu.  (1/22)

"Bird flu is the current threat to the human community".  (1/22)\

January 11-20, 2026

11 European counties confirm cases of bird flu in since the start of the year.  (1/20)

Philippines reports 10 case of bird flu in past 10 days.  (1/17)

New York tells resident don't touch those dead birds.  (1/17)

Bird flu outbreaks in Georgia and Minnesota.  (1/15)

Kansas is currently ground zero for bird flu.  (1/13)

Newcastle Disease, another highly contagious viral disease affecting birds, hit 4 flocks in Spain.  (1/12)

Multiple strains of bird flu has scientists worried.  (1/11)

January 1-10, 2026

Two cases of bird flu hit Sampson County North Carolina.  (1/10)

Bird flu infects flock of 380,000 commercial egg-laying hens in Kansas.  (1/9)

Biggest egg producer in United States remains wary of bird flu.  (1/8)

Bird flu strain of avian influenza:  "The picture has grown darker and stranger than most would have imagined".  (1/8)

Bird flu reported on Martha's Vineyard in Massachusetts. (1/8)

Bird flu wipes out generation of Patagonian seals.  (1/8)

Dozens of vultures die of bird flu in North Carolina.  (1/8)

Dog dies of bird flu in Alberta after eating infected snow goose.  (1/7)

Bird flu reported at 3 sites in North Carolina during 1st week of 2026.  (1/7)

Bird flu hits two gamebird flocks in Kansas.  (1/7)

British Columbia reports most cases of bird flu in among Canadian provinces in 2025.  (1/7)

Nearly half of all 2025 bird flu cases in United States occurred in Ohio and Indiana.  (1/7)

Kerala India reports 11 cases of bird flu in December 2025.  (1/6)

Bird flu infects 144,600 commercial laying hens in Nebraska.  (1/3)

Bird flu puts a damper on goose hunting season in Arkansas.  (1/3)

32,800 ducks infected by bird flu in Lancaster County Pennsylvania.  (1/2)

Geese dying to bird flu in South Dakota.  (1/1)

Bird flu continues to wreak havoc in Indiana.  (1/1)

December 16-31, 2025

Bird flu outbreaks continue apace in Europe.  (12/31)

Maryland reports most recent biggest case of bird flu.  (12/31)

12 swans die of bird flu at Orlando's Lake Eola.  (12/30)

Dangerously setting aside the lessons learned from Covid.  (12/30)

Arkansas reports 3rd case of bird flu in 2025, 1st since January.  (12/29)

Hundreds of geese found dead of bird flu in Pennsylvania's Pymatuning Reservoir.  (12/26)

Egg prices on the rise in South Korea due to bird flu outbreaks.  (12/26)

Bird flu outbreak in Japan results in culling of nearly 1,000,000 egg-laying hens.  (12/26)

"A global problem:  Ominous outlook for bird flu in 2026.  (12/25)

Avian flu now encircles Australia.  (12/24)

Ontario reports two new cases of avian flu.  (12/24)

Europe continues to deal with outbreaks of avian flu.  (12/24)

United Kingdom avian flu tally reaches 73 during 2025-26 season.  (12/22)

Recent outbreak of avian flu in Texas affected 260,000 commercial broilers.  (12/18)

Hundreds of snow geese found dead of avian flu at Pennsylvania quarry.  (12/17)

Indiana boosts its 2025 avian flu tally to 66. (12/17)

2025 avian flu tally in Europe:  654 outbreaks in 23 countries.  (12/17)

Texas reports its first case of avian flu since April 2024.  (12/16)

December 1-15, 2025

Minnesota reports 22nd case of avian flu in 2025.  (12/15)

Avian flu detected in Wisconsin dairy herd.  (12/14)

Patterns of avian flu outbreaks in Europe:  From farm to farm then, from wild birds to farms now.  (12/12)

Turkey flocks in North Dakota and South Dakota hit with avian flu.  (12/12)

Indiana boosts its avian flu outbreak tally to 64.  (12/11)

Australia awaits its first case of avian flu.  (12/9)

2025 avian flu tally in Indiana reaches 60.  (12/9)

Japan and South Korea report outbreaks of avian flu.  (12/8)

Avian flu kills more than 70 vultures in Ohio.  (12/7)

Latest avian flu research from Iowa State University.  (12/6)

Michigan DNR sends out an avian flu advisory to waterfowl hunters.  (12/6)

Avian flu kills scores of geese in rural Manitoba Canada.  (12/6)

Canadian province of Alberta deals with worse outbreak of avian flu in years.  (12/6)

Avian flu is a global concern.  (12/5)

Massive outbreak of avian flu in Europe during past week.  (12/3)

North Carolina, Ontario, Indiana, and British Columbia on todays avian flu hit parade. (12/2)

Around the world with avian flu.  (12/1)

Edmunds County South Dakota reports two cases of avian flu in less than a week.  (12/1)

November 15-30, 2025

Avian flu detected in wild birds all over Michigan.  (11/30)

4 Ontario poultry farms hit by avian flu in past 2 weeks.  (11/30)

Indiana-based poultry company uses inflatables to shoo away wild birds.  (11/26)

52 poultry flocks in Indiana infected by avian flu so far in 2025.  (11/25)

Washington State reports 3 more cases of avian flu.  (11/24)

First human death from H5N5 strain of avian flu reported in Washington State.  (11/23)

South Dakota reports 17th case of avian flu in 2025.  (11/23)

North Carolina reports first case of avian flu since January.  (11/21)

Widespread outbreaks of avian flu in Europe.  (11/17)

Avian flu wipeout in LaGrange County Indiana.  (11/17)

Bird flu spreads while Trump fiddles  and Dept of Ag secretary  Brooke Rollins poses with chickens.  (11/16)

November 1-15, 2025

Avian flu devastates herd of elephant seals on sub-Antarctic island.  (11/14)

Ottawa County Michigan reports 2 more cases of avian flu, bringing its 2025 total to 8. (11/14)

Avian flu taking a toll in Germany.  (11/13)

Wild birds are spreading avian flu across the United States.  (11/13)

Monitoring the health of poultry through their water consumption.  (11/12)

Another Michigan turkey flock infected with avian flu.  (11/11)

British Columbia ostrich farm loses appeal, 400 birds infected with avian flu depopulated.  (11/11)

]5 swans die of avian flu in Bristol, England.  (11/11)

Germany reports 66 cases of avian flu since October 1.  (11/10)

Avian flu alert in Missouri.  (11/7)

Two recent cases of avian flu in Ottawa County, Michigan.  (11/7)

Japan reports third confirmed outbreak of avian flu this season.  (11/6)

More turkey flocks infected with avian flu in North Dakota and South Dakota.  (11/5)

That raw cheese you're eating might be infected with bird flu virus.  (11/4)

Avian flu infects turkey flock in Michigan.  (11/4)

Four cases of avian flu hit western Canada.  (11/3)

You're right if you think there's been a lot of birds killed by avian flu during the past 2 months.  (11/1)

October 2025

Avian flu hits duck breeder farm in California. (10/29)

139,000 chickens fall victim to avian flu in Georgia.  (10/28)

Avian flu kills elephant seals on Heard Island south of Australia.  (10/25)

Widespread avian flu infections of wild birds in the United States.  (10/24)

Minnesota boosts its 2025 avian flu tally to 20.  (10/23)

Yet another case of avian flu confirmed in Minnesota, bringing total to 19 so far in 2025.  (10/22)

Indiana reports more cases of avian flu.  (10/21)

Quebec reports 4th case of avian flu in 2025.  (10/17)

Three more Minnesota turkey flocks affected by avian flu, bringing 2025 tally to 18 .  (10/16)

Two cases of avian flu reported in Manitoba on consecutive days.  (10/14)

Multiple reports of avian flu including two flocks in Washington State affecting more than 2,200,000 hens.  (10/13)

Bird flu detected in goose at Gibson Park in Great Falls Montana.  (10/12)

Avian flu threat results in cancellation of WIsconsin poultry show.  (10/11)

Avian flu hits two more turkey flock in Minnesota.  (10/10)

Avian flu hits Michigan turkey flock.  (10/9)

Avian flu hits Iowa turkey flock.  (10/7) 

175,000,000 birds have fallen victim to avian flu in United States since 2022.  (10/6)

Migrating season brings a return of avian flu to Iowa.  (10/3)

Jefferson County Wisconsin reports second case of avian flu in less than a week.  (10/3)

September 2025

That Jefferson County Wisconsin farm lost more than 3 million laying hens.  (9/30)

Avian flu claims an historical first death:  Whooping crane.  (9/29)

Wisconsin reports first 2025 commercial case of avian flu in poultry flock without providing any specifics.  (9/29)

Utah in 4th year of avian flu outbreak. (9/27)

Minnesota reports 55,000 cases of avian flu in 3 turkey flocks.  (9/26)

Expect higher prices for your Thanksgiving turkey this year.  (9/26)

South Dakota continues to be hit hard by avian flu.  (9/21)

Minnesota reports avian flu in flock of tom turkeys.  (9/19)

Nebraska reports its first known case of avian flu in dairy herd.  (9/17)

Canadian Food Inspection Agency reports 4 cases of avian flu in Alberta but otherwise remains mum.  (9/17)

South Dakota reports additional cases of avian flu in turkey flocks.  (9/14)

Must be Kristi Noem's bad karma and her Corey Lewandowski hook-up:  South Dakota is ground zero for avian flu so far this fall.  (9/10)

Avian flu is not going away:  Texas records U.S. case #1079 since January 2024.  (9/9)

April-August 2025

You've heard of avian flu, right?  How about Marek's disease?  (8/7)

Public relations news:  Not a good year so far for chickens and eggs.  (6/13)

Wisconsin put poultry shows and exhibitions on hold in 20 southern counties due to recent bird flu outbreak.  (3/14)

Indiana reports four more cases of bird flu.  (3/13)