Friday, March 29, 2024

CDC Updated Advice On Bird Flu in Pets and Other Animals


#17,973


Recent reports suggesting that Vietnam's latest fatal H5N1 case may have contracted the virus through contact with wild birds, and other similar reports in the past (see here and here), have public health agencies once again reminding people of the potential risks to them, and their pets, from avian influenza.

Ten days ago we looked at the UK Guidance for the Public: Minimize Contact with Wild Birds that stressed avoiding contact, and when that isn't possible, the value of wearing of PPEs (gloves, eye protection & masks, etc.), and the importance of post-contact disinfection.

While the risks of infection to dogs and cats (and their owners) is considered low, it is not zero (see J. Virulence: HPAI H5N1 Virus Infection In Companion Animals), and cat-to-human transmission has been reported (see EID Journal: Avian H7N2 Virus in Human Exposed to Sick Cats).

With the recent revelation that HPAI H5 has been detected in two previously unreported farm animals (goats and cows), the need for public vigilance has only increased. 

The CDC has recently (March 21st) updated their advice to the public on bird flu in pets and other animals, excerpts of which you'll find below.

Bird Flu in Pets and Other Animals

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People Who Have Had Direct Contact with Infected or Potentially Infected Animals



Although bird flu viruses mainly infect and spread among wild migratory water birds and domestic poultry, some bird flu viruses can infect and spread to other animals as well.
Bird flu viruses have in the past been known to sometimes infect mammals that eat (presumably infected) birds or poultry, including but not limited to wild animals, such as seals, bears, foxes, skunks; farmed mink; stray or domestic animals, such as cats and dogs; and zoo animals, such as tigers and leopards.
H5N1 bird flu viruses have been detected sporadically in some domestic animals, including cats during outbreaks in Thailand in 2004 and Northern Germany in 2006, and cats, dogs, and goat kids (juvenile goats) in North America. In December 2023, H5N1 virus infections were reported for the first time in mammals in both polar regions: an infected polar bear, which died in Alaska, and in elephant and fur seals in the Antarctic.
While it’s unlikely that people would become infected with bird flu viruses through contact with an infected wild, stray, feral, or domestic mammal, it is possible—especially if there is prolonged and unprotected exposure to the animal. This page provides information for different groups of people who might have direct contact with infected or potentially infected sick or dead animals, including animals that might have eaten or been exposed to bird flu-infected birds.

Pet Owners

If your domestic animals (e.g., cats or dogs) go outside and could potentially eat or be exposed to sick or dead birds infected with bird flu viruses, or an environment contaminated with bird flu virus, they could become infected with bird flu. While it’s unlikely that you would get sick with bird flu through direct contact with your infected pet, it is possible. For example, in 2016, the spread of bird flu from a cat to a person was reported in NYC. The person who was infected [2.29 MB, 4 pages] was a veterinarian who had mild flu symptoms after prolonged exposure to sick cats without using personal protective equipment.

If your pet is showing signs of illness compatible with bird flu virus infection and has been exposed to infected (sick or dead) wild birds/poultry, you should monitor your health for signs of fever or infection.

More Information




Take precautions to prevent the spread of bird flu.

As a general precaution, people should avoid direct contact with wild birds and observe wild birds only from a distance, whenever possible. People should also avoid contact between their pets (e.g., pet birds, dogs and cats) with wild birds. Don’t touch sick or dead birds, their feces or litter, or any surface or water source (e.g., ponds, waterers, buckets, pans, troughs) that might be contaminated with their saliva, feces, or any other bodily fluids without wearing personal protective equipment (PPE).
More information about specific precautions to take for preventing the spread of bird flu viruses between animals and people is available at Prevention and Antiviral Treatment of Bird Flu Viruses in People. Additional information about the appropriate PPE to wear is available at Backyard Flock Owners: Take Steps to Protect Yourself from Avian Influenza.
People Who Have Had Direct Contact with Infected or Potentially Infected Animals

During outbreaks of bird flu in wild birds and/or poultry, people who have had direct contact with infected or potentially infected animals, including sick animals that might have eaten bird flu-infected birds, should monitor their health for fever and symptoms of infection.

Signs and Symptoms may include:
  • Fever (Temperature of 100°F [37.8°C] or greater) or feeling feverish/chills*
  • Cough
  • Sore throat
  • Difficulty breathing/Shortness of breath
  • Conjunctivitis (eye tearing, redness, irritation, or discharge from eye)
  • Headaches
  • Runny or stuffy nose
  • Muscle or body aches
  • Diarrhea
*Fever may not always be present

Call your state/local health department immediately if you develop any of these signs or symptoms during the 10-days after your exposure to an infected or potentially infected animal. Discuss your potential exposure and ask about testing. If testing is recommended, isolate as much as possible until test results come back and/or you have recovered from your illness.

Additionally, close contacts (family members, etc.) of people who have been exposed to a person or animal with lab-confirmed bird flu viruses should also monitor their health for 10 days after their exposure for signs and symptoms of illness. If close contacts of people who have been exposed to H5 bird flu viruses develop signs and symptoms of illness, they should also contact their state health department. precautions to prevent the spread of bird flu.

(Continue . . . )

 

Idaho Ag Dept.: HPAI Detection in Idaho Dairy Herd

 

Cassia Count, ID Credit Wikipedia

#17,972

Overnight Treyfish and other volunteer newshounds on FluTrackers posted media and official reports (see thread here) on the detection of HPAI in a dairy herd in yet another state: Idaho.  

Unlike previous official statements, which have strongly suggested wild birds as the source of these infections, Idaho's State Department of Agriculture (ISDA) specifically mentions the possibility of cow-to-cow transmission. 

They report that the affected facility had recently imported cows from another state which is now reporting HPAI in cattle, and they may be the source of local infection.  

All of this is quite preliminary, but if the virus is found to be transmitting from cow-to-cow, that would be a worrisome development. 

First the press release from the ISDA, after which I'll have a bit more.

HPAI Detection in Idaho Dairy Herd

Boise, Idaho – The Idaho State Department of Agriculture (ISDA) identified today highly pathogenic avian influenza (HPAI) in a Cassia County dairy cattle operation.

These are the first cases of HPAI in a livestock operation in Idaho. The affected facility recently imported cattle from another state that has identified cases of HPAI in cattle, which suggests the virus may be transmitted from cow-to-cowin addition to previous reports indicating cattle were acquiring the virus from infected birds.

The primary concern with this diagnosis is on-farm production losses, as the disease has been associated with decreased milk production.

Symptoms of HPAI in cattle include:
  • Drop in milk production
  • Loss of appetite
  • Changes in manure consistency
  • Thickened or colostrum-like milk
  • Low-grade fever
At this stage, there is no concern about the safety of the commercial milk supply or that this circumstance poses a risk to consumer health. The pasteurization process of heating milk to a high temperature ensures milk and dairy products can be consumed safely.

The ISDA encourages all dairy producers to closely monitor their herd and contact their local veterinarian immediately if cattle appear to show symptoms. HPAI is a mandatory reportable disease, and any Idaho veterinarians who suspect cases of HPAI in livestock should immediately report it to ISDA at 208-332-8540 or complete the HPAI Livestock Screen at agri.idaho.gov/main/animals/hpai/.

It is recommended to enhance biosecurity measures across all livestock facilities in Idaho. Biosecurity practices can be found at agri.idaho.gov/main/animals/hpai/.

For decades, Idaho has worked diligently to implement industry-driven programs that mitigate the transmission of diseases that cause on-farm economic losses. ISDA’s response to the detection of HPAI in cattle aligns with standard ISDA animal disease detection procedure.

This is an evolving situation, and additional updates will be provided by ISDA as they become available.

For more information visit agri.idaho.gov/main/animals/hpai/ or contact ISDA Animal Industries Division (208) 332-8540.

Media Inquiries

Sydney Kennedy
media@isda.idaho.gov
(208) 332-8507


Regardless of whether this virus is spreading from cow-to-cow, or is the result of direct exposure to infected birds (or their feces), we have a habit of underestimating HPAI.  Two weeks ago, the notion that HPAI would be infecting cattle and goats across 5 states would have been considered ludicrous.

So much so, that it apparently took several weeks into the investigation of sick cows in Texas before they decided to test for the virus (see Lisa Schnirring's CIDRAP article Avian flu detections in dairy cows raise more key questions).

If HPAI has been infecting (and possibly spreading) in cows undetected for months, it begs the question, what other reservoirs are we overlooking? 

Pigs obviously rank high on our list (see Netherlands: Zoonoses Experts Council (DB-Z) Risk Assessment & Warning of Swine As `Mixing Vessels' For Avian Flu), and with the summer & fall county and state fair season soon to begin, may require additional scrutiny. 

Last summer, in Avian Flu's New Normal: When the Extraordinary Becomes Ordinary, I wrote how outbreaks and spillovers that were nearly unthinkable two or three years ago have now become `the new normal'.

While it remains unknown whether avian H5 viruses will ever adapt well enough to humans to spark a pandemic, they continue to exceed our expectations. 

 

Thursday, March 28, 2024

Mexico Reports HPAI H5N2 For the 1st Time in Nearly 30 Years

Credit Wikipedia

#17,971

Long before the emergence of the Asian lineage of the HPAI H5N1 virus in Guangdong Province in the mid-1990s, both LPAI (Low path avian influenza) and HPAI (High path) H5 viruses circulated in wild birds and poultry around the globe.   
The earliest known HPAI H5 virus was A/chicken/Scotland/59 (H5N1), which killed two flocks of chickens in Scotland in 1959. China's H5N1 virus rose to fame because it was the first HPAI H5 virus known to infect and sicken humans. 
During the 1980s and 1990s, a North American lineage of LPAI and HPAI H5N2 infected poultry flocks in the United States, Mexico, and the Dominican Republic.  The USDA cites two major outbreaks:

  • The 1983-84 HPAI H5N2 outbreak resulted in humanely euthanizing approximately 17 million chickens, turkeys and guinea fowl in Pennsylvania and Virginia to contain and eradicate the disease.
  •  In 2004, USDA confirmed an HPAI H5N2 outbreak in chickens in Texas. The disease was quickly eradicated thanks to close coordination and cooperation between USDA and State, local, and industry leaders.   
Mexico dealt primarily with LPAI H5N2 until the mid-1990s, when an outbreaks of HPAI H5N2 in Puebla, Mexico prompted the government to adopt poultry vaccination. Over the past 30 years, Mexico's LPAI H5N2 has reportedly diversified into 5 distinct clades (see Evolutionary Dynamics of Mexican Lineage H5N2 Avian Influenza Viruses). 

This week, for the first time since June of 1995, Mexico is reporting HPAI H5N2 on a non-commercial poultry farm with 117 free-range birds.  The WAHIS report states:
EPIDEMIOLOGICAL COMMENTS
The presence of highly pathogenic avian influenza (HPAI) virus subtype H5N2 was confirmed through PCR tests, virus isolation, genetic sequencing and intravenous pathogenicity index (IVPI) test, in the state of Michoacán, in a backyard farm. The premises have no contact with other poultry because no commercial poultry farm is implemented in the municipality. The sanitary situation of Mexico regarding this disease remains unchanged, since HPAI subtype H5N2 is not present in birds defined as "poultry" at the moment.

SENASICA is furthering its epidemiological investigation of the event and continues to urge poultry farmers to reinforce biosecurity measures on their farms and to immediately notify any anomaly observed in their animals, in order to protect national poultry production. The active epidemiological surveillance program is being maintained in technified production units, backyards, federally inspected slaughterhouses and municipal slaughterhouses as well as the monitoring of wild birds at national level.

Mexico's SENASICA reports:


Highly pathogenic AH5N2 avian influenza registered in a backyard unit in Michoacán
This epidemiological event does not represent a risk to human health, since the virus is exclusive to birds, nor does it affect the supply of chicken and eggs for the country.

National Agri-Food Health, Safety and Quality Service | March 27, 2024 | Release

The General Directorate of Animal Health of Senasica highlighted that commercial poultry farming is not involved.


The National Agri-Food Health, Safety and Quality Service (Senasica) confirmed the presence of highly pathogenic avian influenza (HPAI) AH5N2 in a free-range family production unit in Huetamo, Michoacán.

The General Directorate of Animal Health (DGSA) of Senasica highlighted that commercial poultry farming is not involved, explaining that the virus was detected in an isolated area and there are no commercial poultry farms registered in at least 100 kilometers around, therefore that the outbreak does not compromise the animal health status of our country.

This epidemiological event does not represent a risk to human health, since the virus is exclusive to birds, nor does it affect the supply of chicken and eggs for the entire country, which is why an increase in the prices of these poultry products is not seen. .

The agency of the Ministry of Agriculture and Rural Development reported that doctors from the Directorate of the Mexico-United States Commission for the Prevention of Foot and Mouth Disease and other Exotic Animal Diseases (CPA) of the DGSA began the investigation after A veterinarian reported high mortality on a farm that raised birds for self-consumption, in which, of a total of 120 birds, 117 had died at the time of the report.

Given the discovery, the DGSA immediately ordered the backyard unit to be quarantined and the CPA doctors applied the necessary counter-epidemic measures to deactivate the outbreak, such as cleaning, disinfection and establishing a sanitary vacuum period.

The first molecular biology RT-PCR results issued by official laboratories confirmed the presence of an H5 avian influenza virus, subsequently, through specialized tests, including viral isolation, primary genomic sequencing and the intravenous pathogenicity index. , it was confirmed that it was a highly pathogenic H5N2 avian influenza virus.

Agriculture's specialists in animal health emergency care carry out the corresponding investigations in the area to determine the origin of the infection. The activities carried out in the field are perifocal tracking in the surrounding properties and promotion of notification. Additionally, monitoring of wild birds found near the affected site was implemented in order to determine the source of contagion.

At this time, the official DGSA laboratories are carrying out deep genetic sequencing studies with the purpose of determining the possible origin of the virus.

Senasica urged poultry producers throughout the country not to let their guard down and strengthen biosafety measures in their poultry production units, both family and commercial, with the purpose of mitigating the risk of infections in domestic birds.

The highly pathogenic AH5N2 virus was identified in Mexico in commercial flocks in 1994 and was eradicated in 1995. Since then, our country has remained free of this highly pathogenic agent.

Any person who produces, processes, handles, moves or markets birds must immediately report to the health authority any abnormal behavior in their flocks, unusual mortality or any other suspicion of this disease to the telephone number 800 751 2100, or from their mobile phone through of the “AVISE” app, available for Android devices.

It isn't clear whether this H5N2 virus is a reassortment of HPAI H5N1 clade 2.3.4.4b, or a new incarnation caused by the spontaneous mutation of an LPAI H5 virus into an HPAI (see graphic below).

The fact that it was detected in a small, non-commercial flock, in a relatively remote region of Mexico may help contain this incident.  But given HPAI H5's tendency to overachieve, it's worth our keeping an eye on.

Wednesday, March 27, 2024

WAHIS Report On HPAI H5N1 Virus Detected In US Cattle

Credit https://comptroller.texas.gov/ 

#17,970

Information on the HPAI H5 infections in cattle in Texas and Kansas remains scant, but late yesterday the WOAH WAHIS dashboard carried the following brief preliminary epidemiological report on the virus.

EPIDEMIOLOGICAL COMMENTS

Highly pathogenic avian influenza (HPAI) H5N1 Eurasian lineage goose/Guangdong clade 2.3.4.4b was confirmed in samples from sick cattle collected from at least one dairy farm in Kansas and at least one dairy farm in Texas.
The initial sequences represent a sporadically detected 4 gene reassortant (B3.13 per GenoFlu) descended from the previously predominant genotype B3.2 first observed in wild birds in November 2023. No markers for mammalian adaptation nor antiviral resistance were observed.
This is an evolving situation - additional work and studies are in process. Federal and state agencies are moving quickly to conduct additional testing for HPAI, as well as viral genome sequencing, so that we can better understand the situation, including characterization of the HPAI strain or strains associated with these detections.

We've discussed often that we aren't dealing with a single H5N1 threat, but rather with an array of similar H5N1 viruses that are continually reassorting and evolving.  As a segmented virus with 8 largely interchangeable parts, the flu virus is like a viral LEGO (TM) set which allows for the creation of unique variants called genotypes. 


Genotypes are created when two flu viruses inhabit the same host, allowing them to reassort into a hybrid.  Even when we limit the field to a specific subtype (like H5N1), and a specific sub-clade (like 2.3.4.4b), there can still be dozens of genotypes due to reassortment.

Although this is rapidly changing situation, last fall researchers from several U.S. labs published a `snapshot' of H5N1's diversity in the United States in the months following its arrival in December of 2021, which found that the virus rapidly reassorted with local wild bird avian influenza viruses generating six major (and numerous minor) genotypes.



 Sungsu Youk a f, Mia Kim Torchetti b, Kristina Lantz b, Julianna B. Lenoch c, Mary Lea Killian b, Christina Leyson a, Sarah N. Bevins c, Krista Dilione c, Hon S. Ip d, David E. Stallknecht e, Rebecca L. Poulson e, David L. Suarez a, David E. Swayne a, Mary J. Pantin-Jackwood a

Abstract
Highly pathogenic avian influenza viruses (HPAIVs) of the A/goose/Guangdong/1/1996 lineage H5 clade 2.3.4.4b continue to have a devastating effect on domestic and wild birds. Full genome sequence analyses using 1369 H5N1 HPAIVs detected in the United States (U.S.) in wild birds, commercial poultry, and backyard flocks from December 2021 to April 2022, showed three phylogenetically distinct H5N1 virus introductions in the U.S. by wild birds.
Unreassorted Eurasian genotypes A1 and A2 entered the Northeast Atlantic states, whereas a genetically distinct A3 genotype was detected in Alaska. The A1 genotype spread westward via wild bird migration and reassorted with North American wild bird avian influenza viruses. Reassortments of up to five internal genes generated a total of 21 distinct clusters; of these, six genotypes represented 92% of the HPAIVs examined. By phylodynamic analyses, most detections in domestic birds were shown to be point-source transmissions from wild birds, with limited farm-to-farm spread.

While some genotypes fare better than others, new reassortants tend to cluster in different geographic regions.  Some may thrive and spread widely, while others may be less biologically `fit', and are unable to compete. 


Hopefully we'll get a more detailed analysis of this virus in the days ahead, along with a better idea of its spread in cattle, goats, and potentially other livestock.

National Tsunami Awareness Week 2024

 
#17,969

Today (March 27th) is the 60th anniversary of the Great Alaskan earthquake of 1964, and that state will test its tsunami warning system (see announcement below) later today as part of National Tsunami Awareness Week.

Officials to Test Tsunami Warning System in Alaska March 27, 2024

On Wednesday, March 27th at approximately 10:20 am, the National Weather Service, Alaska Division of Homeland Security and Emergency Management, and the Alaska Broadcasters Association will conduct a test of the Alaska tsunami warning system as a part of tsunami preparedness week in Alaska. The test will be broadcast on radio and television stations and the broadcast will state that it is only a test. Some communities may activate their sirens. NOAA Weather Radio listeners will hear a tone alert followed by a test message. The test will not be sent to cellphones via the Wireless Emergency Alert (WEA) system, although in an actual Tsunami Warning this system would be used.

After the test, we invite you to provide feedback at www.ready.alaska.gov.

Once again, a tsunami warning system test will be conducted on Wednesday, March 27th at approximately 10:20 am. The test will be canceled in the event of any significant seismic activity.
Alaska's 1964 earthquake produced significant tsunami effects both locally, and thousands of miles away, killing 5 in Oregon and 13 in California. March 11th was also the 13th anniversary of Japan's 2011 Tōhoku Earthquake & Tsunami which killed in excess of 15,000 people. 

In 1960 Chile's Valdivia 9.4–9.6 earthquake sent a train of tsunamis across the Pacific, causing heavy damage and loss of life in Hawaii, Japan, and beyond (see NOAA Report).

 

Tsunamis are usually generated by large earthquakes, or underwater volcanic explosions, although massive undersea avalanches - and in rare instances - an asteroid strike can generate one.  

The west coast of North America, since it is vulnerable to tsunamis generated by seismic events in JapanAlaska, and throughout the Pacific rim - including the long expected `big one' off the Pacific Northwest's coast (see Just A Matter Of Time) - is viewed as the most `at risk' region of the continental United States and Canada.

In 2013 the USGS released a report detailing the likely West Coast impact of a tsunami generated by a 9.1 Alaskan earthquake – and the numbers are sobering.  From the USGS news release  Experts Team Up on Tsunami Resilience in California:

In this scenario approximately 750,000 people would need to be evacuated, with 90,000 of those being tourists and visitors. Additionally, one-third of the boats in California's marinas could be damaged or completely sunk, resulting in $700 million in losses. It was concluded that neither of California's nuclear power plants would likely be damaged by this particular event.

The study (link) also estimates damage to marinas, businesses and homes range between $3.5 billion and $6 billion, and as many as 8,500 could be left homeless. 

But, as we've discussed previously (see The Caribbean’s Hidden Tsunami Potential (Revisited), both the Caribbean and the Atlantic also have a history of seismic activity, making our East and Gulf Coast vulnerable to tidal waves as well.

In 1995, Montserrat's previously dormant Soufrière Hills volcano sprang to life, destroying the capital city of Plymouth, and rendering half the island uninhabitable.

In 2013 the USGS warned the Earthquake/Tsunami Hazard in Caribbean Higher Than Previously Thought, stating `Enough strain may be currently stored in an earthquake zone near the island of Guadeloupe to cause a magnitude 8 or larger earthquake and subsequent tsunami in the Caribbean’

A list of known or suspected Atlantic Tsunamis includes:
  • November 1, 1755 - Lisbon, Portugal
  • October 11, 1918 - Puerto Rico
  • November 18, 1929 - Newfoundland
  • August 4, 1946 - Dominican Republic
  • August 18, 1946 - Dominican Republic
  • November 14, 1840 - Great Swell on the Delaware River
  • November 17, 1872 - Maine
  • January 9, 1926 - Maine
  • May 19, 1964 - Northeast USA
Around 11pm on July 3rd, 1992, a `rogue wave' - described by witnesses as being between 10 and 18 feet tall - slammed onto a 27 mile stretch of Florida Beaches (including Daytona Beach) and smashed hundreds of cars and caused as many as 75 (mostly minor) injuries.

Tsunami Risk Maps 

Even if you don't live close enough to the coast to be directly affected by a Tsunami, a major natural disaster anywhere near you can impact your life as well. Supply chains may be disrupted, roads, railways, and ports may be damaged, and utilities like power and water may be out for an extended period of time.

Knowing your local threats, whether they be tsunamis, forest fires, floods, earthquakes or hurricanes . . . and then becoming prepared to deal with them, will provide you and your family the best safety insurance available.

For information on how to prepare for a tsunami, and how to react to an imminent threat, you should visit https://www.tsunamizone.org/

The U.S. National Tsunami Hazard Mitigation Program (NTHMP) has recently released their 5-year Tsunami Hazard mitigation plan in the form of a 43-page PDF, which you can download at this link. 



For help in getting better prepared for a variety of emergencies, I would invite you to visit:

FEMA http://www.fema.gov/index.shtm

READY.GOV http://www.ready.gov/

AMERICAN RED CROSS http://www.redcross.org/





ECDC/EFSA Quarterly Avian Influenza Overview Dec 2023 - Mar 2024


#17,968

While one can be comforted by the relatively low number of confirmed human avian flu infections since 2015 (see ECDC/EFSA chart above), by almost every other metric the avian flu threat appears to be increasing around the globe. 

HPAI H5Nx clade 2.3.4.4b in particular has made great strides, expanding both its geographic and host range, but it is far from alone. We are also closely monitoring several other zoonotic influenza viruses including H3N8, H5N6, LPAI H9N2, and H5N1 clade 2.3.2.1c.


The HPAI H5 threat has changed substantially over the past 8 years, starting out with a recently reassorted H5N8 in 2016, then transitioning (via reassortment) to H5N6 in 2018, and then finally back to H5N1 in 2020. With these changes in subtype came significant changes in its behavior.
While H5N1 is the dominant subtype, there dozens of genotypes circulating in Europe, with even more globally. Some of these genotypes are likely more dangerous, or better adapted to mammals, than others.
Perhaps most concerning, we've seen a record number of mammalian spillovers around the world - most recently involving farmed cattle and goats in the United States - something which has never been reported previously.  This is in addition to tens of thousands of marine and terrestrial mammals killed by the virus over the past 3 years. 
Surveillance and reporting from many regions of the world being limited, it is likely that many spillover events - and some human infections - go unreported.
Four times a year the ECDC publishes a highly detailed avian influenza surveillance report and while they tend to be EU centric, in its 69 pages you'll find substantial coverage of outbreaks and infections from around the world.  

These reports make excellent (and frequently updated) reference material, and I keep the latest version on my desktop for that very reason.  

Due to its length, I've just reproduced the executive summary and link below.  Highly recommended.

Avian influenza overview December 2023–March 2024

Surveillance and monitoring
26 Mar 2024
Time period covered: December 2023–March 2024

Between 2 December 2023 and 15 March 2024, highly pathogenic avian influenza (HPAI) A(H5) outbreaks were reported in domestic (227) and wild (414) birds across 26 countries in Europe.

Executive summary

Compared to previous years, although still widespread, the overall number of HPAI virus detections in birds was significantly lower, among other reasons, possibly due to some level of flock immunity in previously affected wild bird species, resulting in reduced contamination of the environment, and a different composition of circulating A(H5N1) genotypes.
Most HPAI outbreaks reported in poultry were primary outbreaks following the introduction of the virus by wild birds. Outside Europe, the majority of outbreaks in poultry were still clustered in North America, while the spread of A(H5) to more naïve wild bird populations on mainland Antarctica is of particular c
possibly due to some level of flock immunity in previously affected wild bird species
oncern.
For mammals, A(H5N5) was reported for the first time in Europe, while goat kids in the United States of America represented the first natural A(H5N1) infection in ruminants.
Since the last report and as of 12 March 2024, five human avian influenza A(H5N1) infections, including one death, three of which were clade 2.3.2.1c viruses, have been reported by Cambodia. China has reported two human infections, including one fatal case, with avian influenza A(H5N6), four human infections with avian influenza A(H9N2) and one fatal case with co-infection of seasonal influenza A(H3N2) and avian influenza A(H10N5). The latter case was the first documented human infection with avian influenza A(H10N5).
Human infections with avian influenza remain rare and no sustained human-to-human infection has been observed. The risk of infection with currently circulating avian H5 influenza viruses of clade 2.3.4.4b in Europe remains low for the general population in the EU/EEA. The risk of infection remains low to moderate for those occupationally or otherwise exposed to infected animals.

        Avian influenza overview December 2023–March 2024 - EN - [PDF-2.71 MB]