Bird flu in Canada: What to know about poultry and milk safety

By Nicole Ireland

 The Canadian Press
Posted November 15, 2024 

WATCH: British Columbia’s health ministry says the first suspected human case of avian influenza has been detected in Canada.


People have been hearing a lot about H5N1 bird flu — or highly pathogenic avian influenza — since a B.C. teen became the first human to get the virus in Canada and is in hospital.

It’s not yet known how the teen got infected, but Dr. Theresa Tam, Canada’s chief public health officer, said on Wednesday that genomic sequencing shows they have a strain of H5N1 similar to the strains found in poultry farm outbreaks in British Columbia.

More than 20 locations with infected poultry have been identified in the province since the beginning of October, according to a news release posted recently on the B.C. government website.

The H5N1 strain the teen has is not the same genotype that’s been found in people who were infected by dairy cattle in the U.S., Tam said in an interview.

While there have been several outbreaks of bird flu on dairy farms in multiple states, the virus has not been detected on dairy farms anywhere in Canada.

3:37  H5N1 avian flu detected in teen




How do we know dairy cattle in Canada aren't infected with H5N1?

The Canadian Food Inspection Agency has been testing raw milk arriving at processing plants in each province for the bird flu virus.

It has also been testing pasteurized retail milk samples.

Tam said that like wastewater testing for viruses such as COVID-19 and seasonal flu, the milk testing aims to provide an “early warning” signal if H5N1 has reached dairy farms in Canada.

If H5N1 ends up in milk, is it still safe to drink?

Yes, as long as milk has been pasteurized, the Canadian Food Inspection Agency says.

“In Canada, milk must be pasteurized before sale. The pasteurization process kills harmful bacteria and viruses, including HPAI (highly pathogenic avian influenza), ensuring milk and milk products are safe to drink and eat,” the CFIA website says.

Is it safe to eat poultry, eggs and beef?

Yes, as long as they are cooked thoroughly.

Where are the infected poultry farms in Canada?

As of Nov. 13, there were 28 infected poultry locations in British Columbia, two in Alberta and one in Saskatchewan, according to the Canadian Food Inspection Agency’s website.

Shayan Sharif, a pathobiology professor at the Ontario Veterinary College at the University of Guelph, said he believes H5N1 will reach poultry farms in other provinces.

“I hope to be proven wrong … but I think it’s probably going to come eastward in the not too distant future,” he told The Canadian Press.

1:53 What risk do zoonotic diseases pose?

What do you do when there is an H5N1 infection on a farm?

Farmers are required to notify the CFIA if they suspect their birds or livestock have avian flu

All poultry must be killed on farms that have tested positive for H5N1, said Sharif. But cattle don’t have to be killed, he said.

The virus can be spread through direct contact with infected animals, but can also spread through contaminated barns and other environments.

“Biosecurity” is one of the most important ways to stop the spread of avian flu between farms, Sharif said.

That means workers should wear personal protective equipment and change clothing when they enter and exit a farm where avian flu has been detected.

2:16  WHO says Bird flu risk to humans an ‘enormous concern,’ but what should you know?

It also means not sharing equipment between farms, as well as washing and disinfecting trucks delivering supplies and feed, he said.

Sharif said he supports offering avian flu vaccines to farm workers — a move that Finland has adopted.

Health Canada has authorized three influenza vaccines that could be used to protect against H5N1 avian flu.

Those vaccines are not currently available here, but Tam said public health officials are “very interested” in learning from Finland and are actively looking into the potential use of H5N1 vaccines as they monitor avian flu activity in Canada.

First presumptive human case of avian flu acquired in Canada detected in teen

November 09, 2024 

Provincial health officer Dr. Bonnie Henry speaks in Victoria on Thursday, March 10, 2022.

 British Columbia's Ministry of Health says the first suspected human case of bird flu contracted in Canada has been detected in B.C.

 THE CANADIAN PRESS/Chad Hipolito

British Columbia’s Ministry of Health says the first suspected human case of bird flu contracted in Canada has been detected in B.C.

A statement from the office of the provincial health officer says a teenager in the region covered by Fraser Health tested positive for bird flu, and the teen is currently getting treatment at BC Children’s Hospital.

The statement says the positive test was done by the BC Centre for Disease Control, and samples are on their way to Winnipeg’s national microbiology lab for confirmatory testing

It says public health officials are also looking into the case to find the source of exposure and identify any contacts.

Provincial health officer Dr. Bonnie Henry says it is “a rare event” and only a handful of cases of bird flu, caused by the H5N1 strain of the avian influenza virus, have been detected in humans in the U.S. and abroad.

The statement says the source of the teen’s exposure to the virus is very likely to be from an animal or bird, while public health officials and the province’s chief veterinarian investigate.

This report by The Canadian Press was first published Nov. 9, 2024.

Province reports first presumptive positive human case of H5 avian influenza in BC and Canada

BC sees first case of bird flu

Casey Richardson - Nov 9, 2024 / 4:09 pm | Story: 516614

Photo: The Canadian Press

BC announced on Saturday afternoon that an individual in British Columbia had tested presumptive positive for avian influenza, also known as bird flu.

This was the first detection of avian influenza due to the H5 virus in a person in B.C.

The province said this is also the first detection of a presumed human case of H5 avian influenza acquired in Canada.

"The positive test for H5 was performed at the BC Centre for Disease Control's Public-Health Laboratory. Samples are being sent to the National Microbiology Laboratory in Winnipeg for confirmatory testing," the province added.

Currently, the individual, who is a teenager from the Fraser Health region, is receiving care at BC Children's Hospital.

The province said a public health investigation has begun to determine the source of exposure and identify any contacts.

"Our thoughts are with this young person and their family during this difficult time," said Dr. Bonnie Henry, B.C.'s provincial health officer in the news release.

"This is a rare event, and while it is the first detected case of H5 in a person in B.C. or in Canada, there have been a small number of human cases in the U.S. and elsewhere, which is why we are conducting a thorough investigation to fully understand the source of exposure here in B.C."

Anyone who may have been exposed will be contacted by public health to assess for symptoms and provide guidance on testing and prevention measures.

There have been no further cases identified or reported at this time, according to the province.

B.C.'s chief veterinarian and public health teams are also investigating since the source of exposure is believed to be very likely an animal or bird.

The investigation involves public health teams from Fraser Health, BC Centre for Disease Control (BCCDC), the BCCDC Public Health Laboratory, BC Children's Hospital, the Office of the Provincial Health Officer, the Office of the Chief Veterinarian, the Ministry of Agriculture and Food, and others.

"Health, animal and environmental partners across B.C. have also been working together and with the Canadian Food Inspection Agency and other national and U.S. partners to respond to the increased detections of H5N1 avian influenza in poultry farms and wild birds in the province since early October," the province said.

To protect yourself against avian influenza, the following prevention measures are recommended by the province:

• Stay up to date on all immunizations, especially the seasonal flu vaccine.
• Do not touch sick or dead animals or their droppings and do not bring sick wild animals into your home.
• Keep your pets away from sick or dead animals and their feces (poo).
• Report dead or sick birds or animals.
• For poultry or livestock, contact the Canadian Food Inspection Agency (CFIA) Animal Health office: https://inspection.canada.ca/en/about-cfia/contact-cfia-office-telephone#bc-animal(https://https://inspection.canada.ca/en/about-cfia/contact-cfia-office-telephone#bc-animal)
• For pets, contact your veterinarian or call the BC Animal Health Centre at 1 800 661-9903
• For wild birds, contact the BC Wild Bird Mortality Line: 1 866 431-2473
• For wild mammals, contact the BC Wildlife Health Program: 1 250 751-7246

For those who may have been exposed to sick or dead birds or animals or work on a farm where avian influenza has been detected, they are asked to watch for symptoms of influenza-like illness.

Symptoms within 10 days after exposure to sick or dead animals should be reported to a health-care provider, notifying them that you have been in contact with sick animals and are concerned about avian influenza.

"This will help them give you appropriate advice on testing and treatment. Stay home and away from others while you have symptoms."

H5N1 has been detected in wild birds, on poultry farms and among small wild mammals, including skunks and foxes within BC.

The province said most cases have been reported during migration season when wild birds carrying the virus are in high numbers.

"Since the beginning of October 2024, at least 22 infected poultry premises have been identified in B.C., along with numerous wild birds testing positive"

However, there have been no cases reported in dairy cattle and no evidence of avian influenza in samples of milk in BC or Canada.

"Influenza viruses are adaptable and can change when strains from humans or different animal species mix and exchange genetic information. Avian influenza could become more serious if the virus develops the ability to transmit from person to person, with potential for human-to-human transmission" the province said.

More information can be found online here.

 

Washington coast avian flu outbreak devastated Caspian terns, jumped to seals

Washington State University

 

image: 

The avian flu killed 1,101 adult Caspian terns and 520 chicks in 2023 in a large breeding colony on Rat Island in Washington state. Researchers estimate that as much as 10-14% of terns in the entire Pacific flyway have been lost to the virus.

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Credit: Scott Pearson, Washington Department of Fish & Wildlife

PULLMAN, Wash. – An epidemiological study found that 56% of a large breeding colony of Caspian terns died from a 2023 outbreak of highly pathogenic avian influenza at Rat Island in Washington state. Since then, no birds have successfully bred on the island, raising concerns that the outbreak may have had a significant impact on an already declining Pacific-coast population.

As part of the study, a team including Washington Department of Fish and Wildlife (WDFW) as well as Washington State University researchers also documented that the avian flu virus H5N1was transmitted to harbor seals for the first time in the northeastern Pacific.

While there has not been another large coastal wildlife outbreak of H5N1 since, researchers estimated that about 10-14% of the Caspian tern population in the Pacific flyway have been lost to H5N1 infections.

“This Caspian tern event was the first big marine environment avian flu outbreak for Washington. It caused a significant, punctuated mortality for the Caspian terns, which were already a species in decline throughout this flyway,” said Katherine Haman, a wildlife veterinarian for WDFW and lead author on the study in the journal Frontiers in Veterinary Science.

Caspian terns are found across the country, and until a couple years ago, their largest breeding site was an island in the lower Columbia River, downstream from Portland. Because the birds were feasting on young, endangered salmon, they were discouraged from nesting on that island. It is likely that a portion of the extremely large Columbia River colony relocated to Rat Island near Fort Flagler Park in Jefferson County—then, came the avian flu in 2023.

Haman credited citizen volunteer docents from the Friends of Fort Flagler and local kayaking guides with noticing the first bird deaths on Rat Island early and alerting officials. This allowed researchers to respond early, collecting dead birds and euthanizing sick ones. A total of 1,101 adults and 520 chicks were killed by the outbreak.

The researchers also noted 15 dead harbor seals in the area which usually only sees 1 or 2 seal deaths a year. Through tissue samples, WSU researchers at the Washington Animal Disease Diagnostic Laboratory (WADDL) were able to first identify H5N1 in the birds, but the tests in seals were harder to confirm.

“We tend to think of avian influenza as a respiratory disease, but the seal respiratory samples were initially negative for H5N1. That seemed odd because there was a relatively high mortality in the seals, and there were also birds that were sick at the same time,” said co-author Kevin Snekvik, a WSU veterinary pathologist and WADDL executive director.

Further testing in other organs revealed that avian flu had a different pathology in the harbor seals causing an inflammatory response in their brains. The team performed a whole genome sequencing of the virus confirming that the seals likely contracted the virus from the terns.

Avian influenza has been killing many seals and sea lions in other parts of the world, particularly in South America, but so far that same spread has not yet occurred in the Pacific Northwest. The consequences for the terns in the region, however, has been more dire. There is no vaccine or treatment yet available in the U.S. for animals impacted by the avian flu. It is difficult to control in wildlife given the rapid spread and the difficulty associated with capture and handling of wild animals, so at this stage, researchers are trying to gain insights on the spread of the disease in wild populations by tracking the spread and understanding the impact.

Human cases of avian flu in Washington and elsewhere in the U.S. have occurred primarily in agricultural workers who were in close contact with infected domestic animals, according to the Centers for Disease Control and Prevention.

The researchers emphasized that people should not touch sick or dying wildlife, and instead report the animals on WDFW’s website.

This research received support from the Washington state legislature, Centers for Disease Control and Prevention, National Oceanic and Atmospheric Association, the Washington Department of Health, WDFW and WADDL. The study was made possible by a large collaboration including additional researchers from WSU and WDFW as well as Center Valley Animal Rescue, National Marine Fisheries Service, Pennsylvania State University, Washington Department of Health and University of California, Davis.

“The success of this study and the ongoing investigation is a result of a large number of organizations working together seamlessly. For wildlife investigations, it is absolutely paramount that we work across lines,” said co-author Tom Waltzek, a researcher with WADDL and WSU’s College of Veterinary Medicine.   

The population of Caspian terns were already in decline throughout the Pacific flyway when they suffered a major avian flu outbreak at a large breeding site off the coast of Washington state.

Credit

Scott Pearson, Washington Department of Fish & Wildlife

Researchers were able to respond early to the outbreak of avian flu among Caspian terns in 2023, thanks to the reports from local volunteers and kayaking guides. The event was the first major outbreak of H5N1 among marine wildlife in the region. An estimated 56% of the breeding colony was lost.

Credit

Katherine Haman, Washington Department of Fish & Wildlife

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Journal

Frontiers in Veterinary Science

DOI

10.3389/fvets.2024.1483922 

Article Title

A comprehensive epidemiological approach documenting an outbreak of H5N1 highly pathogenic avian influenza virus clade 2.3.4.4b among gulls, terns, and harbor seals in the Northeastern Pacific

UK govt confirms bird flu outbreak in commercial poultry farm, raises alert level


The UK government said all poultry on the infected premises will be humanely culled. — Reuters pic

Wednesday, 06 Nov 2024 

LONDON, Nov 6 — The UK government said yesterday that cases of bird flu had been confirmed in commercial poultry at premises in Yorkshire, hours after it increased the risk level of the disease from medium to high.

All poultry on the infected premises will be humanely culled, and a three-kilometre protection zone had been put in place surrounding the premises, it said in a statement.

Bird flu, or avian influenza, which has killed hundreds of millions of birds around the globe in recent years, has increasingly spread to mammals, raising concerns it may lead to human-to-human transmission.

Earlier in the day, the government raised its alert level after two different strains of the virus, H5N5 and H5N1, were detected in wild birds in the country over the autumn, according to a government update yesterday.

Britain, which had increased the threat level to medium in mid-October, has experienced several bird flu outbreaks over the years, including one in 2021 that was then described as the largest-ever in the country. — Reuters

New research on mpox, dengue, malaria at tropical medicines event


ByDr. Tim Sandle
DIGITAL JOURNAL
October 22, 2024

A scientist harvests H7N9 virus growing in bird eggs. The Centers for Disease Control and Prevention received samples of the virus from China. — James Gathany/CDC/Douglas E. Jordan / (CC0 1.0)

The 2024 Annual Meeting of the American Society of Tropical Medicine and Hygiene is set to convene thousands of scientists and public health specialists in New Orleans to embrace global health.

Researchers and policy experts will meet against the backdrop of a world still facing regular waves of COVID-19 infections while dealing with a host of new challenges. This includes the declaration of mpox as a global health emergency.

The mpox symposium at the conference will focus on the fight against the recent surge of infections in sub-Saharan Africa and the emergence of an especially dangerous strain that prompted WHO to declare a public health emergency of international concern.

Related mpox presentations at TropMed include new research documenting potentially protective immune responses generated by both mpox and smallpox vaccinations — insights that could inform the development of new drugs, vaccines and diagnostics–and evidence that mpox infections may have been spreading in East Africa. This is the region where the disease was not known to be common, earlier than the 2024 outbreak.

Also under the spotlight is the U.S. threat from Chagas Disease. Experts in this neglected parasitic disease — primarily spread by insects known as kissing bugs — are set to explore the latest evidence for a potentially growing presence in the continental U.S, notably probing risks in California, South Carolina, Louisiana, Arizona and Texas.

As an example, researchers from Tulane are investigating whether the Chagas parasite is circulating among insects and rodents in rural and urban areas of New Orleans.

Further with the U.S., as global progress against leprosy is stagnating — and armadillos emerging as potential carriers in the U.S. — a symposium brings global and domestic experts together to reinvigorate the global fight against the ancient disfiguring bacterial infection also known as Hansen’s disease.

To add to these issues, there has been a surge of dengue outbreaks globally (and rising risks in the U.S.); the worrisome rise of highly pathogenic influenza (H5N1) infections in animal populations and humans with close contact (like U.S. dairy workers); Oropouche virus outbreaks, many of which are under the radar due to lack of approved diagnostic tests.

Furthermore, there have been cholera and diphtheria outbreaks amidst Haiti’s political crisis. There has been a resurgence of cholera in 2022, after two years of relatively low levels of infections, along with diphtheria outbreaks and a potential threat to HIV programs. In addition, a cholera symposium will present evidence from clinical trials testing new cholera vaccines as the world grapples with a vaccine shortage caused by a surge of outbreaks globally in 2021 and 2022.

There is some cause for optimism including the latest evidence from clinical trials of monoclonal antibodies that have shown early promise in providing strong protection against malaria; as well as the latest tools and strategies that could eliminate sleeping sickness.

Monique Wasunna, Africa ambassador for the Drugs for Neglected Diseases initiative (DNDi) and former chief research officer at the Kenya Medical Research Institute (KEMRI), will deliver the opening keynote at the conference.

Dr. Wasunna has served as a principal investigator for clinical trials focused on new treatments for visceral leishmaniasis, malaria and HIV.

Bird flu kills 47 tigers, three lions and a panther at Vietnamese zoos

Sarah Newey
Thu 3 October 2024 

Test results confirmed that the big cats died ‘because of H5N1 type A virus’ - SAEED KHAN/AFP/Getty Images


A panther, three lions and 47 tigers have died from bird flu in zoos in southern Vietnam, further raising concerns about the potential for the virus to evolve to better infect humans.

The fatalities took place in two zoos in August and September near Ho Chi Minh City, state media has reported, and test results from the National Centre for Animal Health Diagnosis later confirmed that the big cats died “because of H5N1 type A virus”. No staff members displayed symptoms.

Experts said the animals likely caught the virus after eating meat from infected poultry.


“Immediate suspicion would be that the zoo animals were infected through whatever they have been given to eat, for example fed chickens that had H5N1,” said Prof Ben Cowling, an epidemiologist at the University of Hong Kong.

He added that this is not common, but that big cats have caught avian influenza before. As the pathogen spread across southeast Asia in 2003 and 2004 – fatally infecting 24 people – two tigers and two leopards also contracted H5N1 at a zoo in Thailand.

But the latest cases come amid mounting uneasiness as bird flu jumps into more and more mammals – including seals, red red foxes and bears – providing space for it to potentially evolve to better infect humans.

“Although avian influenza primarily affects poultry and wild birds, infections in mammals raise concerns about the virus’ potential to adapt and spread across species,” said Dr Bolortuya Purevsuren, a project officer at World Organisation for Animal Health’s southeast Asia office, adding that the Vietnam cross-species infections will be closely monitored.

On a global scale, experts are especially concerned about the seemingly unstoppable outbreak of bird flu in cattle in the United States, where 244 herds in 14 states have been infected – plus at least 14 people. Though these cases have so far been mild, scientists are racing to determine whether there has been human-to-human transmission.

In that outbreak, too, felines have been badly hit – the US Department of Agriculture has detected 43 cases in domestic cats so far this year, with many of them infected after drinking H5 contaminated cows milk.

“So definitely felines seem to be more susceptible to H5N1 than some other mammals,” said Prof Ian Barr, deputy director of the WHO Collaborating Centre for Reference and Research on Influenza in Melbourne.

Dr Charin Modchang, an specialist in disease modelling and epidemiology at Mahidol University in Bangkok, added that he was surprised to see tigers, leopards and panthers infected given the reports of H5 in domestic cats.

“But, from the evolutionary perspective, if the virus can infect and adapt to new mammalian hosts, this should be a concern, as infections in mammals can lead to adaptations that make the virus better suited for mammalian hosts, which are closer to humans than birds,” he said.

“As far as I know, most mammalian H5N1 cases are usually ‘dead-end’ infections with little onward transmission. So the important question is, is this also the case for these tiger infections? How did the tigers get infected, and were there any tiger-to-tiger transmission of the virus? I think we need to find out.”

 

Review shows bird flu control strategies ‘not working’

Gaps in data highlight potential for silent spread

The Pirbright Institute

 

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A chicken 

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Credit: The Pirbright Institute

A review of sustained mammal-to-mammal bird flu transmission in diverse species, led by The Pirbright Institute, shows global control strategies are not working.

Writing in Nature, researchers analysed whether outbreaks in European fur farms, South American marine mammals and United States dairy cattle raise questions about whether humans are next. Led by zoonotic influenza specialist Dr Thomas Peacock, the scientists evaluated how recent changes in the ecology and molecular evolution of H5N1 in wild and domestic birds increase opportunities for spillover to mammals.

They also weighed various evolutionary pathways that could turn the global H5N1 influenza panzootic into a human pandemic virus.

“Influenza A viruses (IAV) have caused more documented global pandemics in human history than any other pathogen. Historically, swine are considered optimal intermediary hosts that help avian influenza viruses adapt to mammals before jumping to humans,” said Dr Peacock, who investigates the drivers of the current H5N1 avian influenza panzootic. “However, the altered ecology of H5N1 has opened the door to new evolutionary pathways.”

The review highlights potential gaps in control mechanisms, including a reluctance to engage with modern vaccine and surveillance technologies and a dearth of data collection around the transmission of H5N1 between cows and to humans on US dairy farms.

Whilst previous generations of US cattle producers had eradicated foot-and-mouth disease by rapidly sharing epidemiological data, the authors say months of missing data is leaving researchers, veterinarians, and policy makers in the dark.

“H5N1 is a reportable disease in poultry, but not mammals, in the US. The US Department of Agriculture requires H5N1 testing only in lactating cattle prior to interstate movement,” said Dr Peacock.

Current practices for H5N1 testing in wildlife focus on carcasses, not monitoring animals whilst alive, the paper notes, providing opportunities for variants of H5N1 to spread silently undetected.

“What keeps scientists up at night is the possibility of unseen chains of transmission silently spreading through farm worker barracks, swine barns, or developing countries, evolving under the radar because testing criteria are narrow, government authorities are feared, or resources are thin.”

An evolutionary process of “genomic reassortment” in viruses with segmented genomes is driving the global panzootic outbreak. When two or more viruses co-infect a single host, they can swap entire segments during genome replication to create novel hybrids.

The reassortment between H5N8 and low pathogenicity avian influenza (LPAI) viruses that generated the panzootic H5N1 virus in the Americas is believed to have occurred in Europe or central Asia around 2020, infecting South American marine mammals and US dairy cattle.

The writers say the prospect of H5N1 becoming continually present in Europe and the Americas is a turning point for High Pathogenicity Avian Influenza (HPAI).

“New control strategies are needed, including vaccination. Influenza vaccines are licensed for poultry that reduce disease burden, but do not prevent infection and have varying degrees of success.”

Stocks of H5 vaccine that are antigenically related to circulating viruses are available and could be produced at scale using mRNA platforms if H5N1 begins spreading in humans, the authors note.

“The severity of a future H5N1 pandemic remains unclear. Recent human infections with H5N1 have a substantially lower case fatality rate compared to prior H5N1 outbreak in Asia, where half of people with reported infections died. The lack of severity in US cases may be due to infection through the eye, rather than through viral pneumonia in the lung.”

Older people appear to have partial immunity to H5N1 due to childhood exposure, whereas younger people born since the 1968 H3N2 pandemic may be more susceptible to severe disease in a H5N1 pandemic.

Dr Peacock’s work is funded by UKRI Biotechnology and Biological Sciences Research Council (BBSRC) via the Pirbright Institute’s Strategic Programme Grants (ISPGs)  and the UK Medical Research Council / Department for Environment, Food and Rural Affairs FluTrailMap One Health consortium, and the BBSRC/DEFRA ‘FluTrailMap’ consortium.

Read the Paper: https://www.nature.com/articles/s41586-024-08054-z

DOI: 10.1038/s41586-024-08054-z

 

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Journal

Nature

DOI

10.1038/s41586-024-08054-z 

Method of Research

Literature review

Article Title

The global H5N1 panzootic in mammals

Article Publication Date

24-Sep-2024

Bird flu detected in Missouri individual who is not a farm worker

This is the 14th human case of bird flu reported this year in the United States and the first without a known occupational exposure to infected animals.

By Lena H. Sun
September 6, 2024 

An individual in Missouri has contracted bird flu, the first human infection unconnected to farm work in an outbreak detected in the spring when the disease was discovered among dairy cows.

The H5N1 avian influenza has spread from cattle to poultry, cats and other animals across the country.

The Missouri individual is the 14th human case of bird flu reported this year in the United States and the first without a known occupational exposure to infected animals, according to the Centers for Disease Control and Prevention. It is also the first time the national flu surveillance system has detected a case of H5 bird flu, the CDC said.

The person was hospitalized Aug. 22, and routine flu testing showed the person had a type of novel nonhuman influenza virus that is different from seasonal human influenza virus. Subsequent testing at the Missouri public health lab and the CDC confirmed the virus as avian flu.

The individual, who has underlying medical conditions that could have made the person more susceptible to respiratory illnesses, was treated with influenza antiviral medication and has recovered. State officials said no transmission among close contacts or others has been identified. Health officials are not providing additional patient information to protect the person’s privacy.

“I’m really glad we have a robust flu system that picked this up, but [it] just begs the question: How many cases have we missed?” said Katelyn Jetelina, an epidemiologist who writes a weekly infectious-diseases newsletter and has closely tracked the avian flu outbreak. “In these situations, we can’t fly blind. If we have a full picture, we can better act, communicate and prevent.”

More than five months into the outbreak, many unanswered questions remain. Public health experts and groups representing farmworkers say the actual number of people infected is certain to be higher because of insufficient testing of people, cows and raw milk.

The outbreak of H5N1 has infected nearly 200 dairy herds in 14 states, according to the U.S. Department of Agriculture; Missouri is not among them. But outbreaks of H5 have been reported in the state’s commercial and backyard poultry flocks this year. H5N1 bird flu has been detected in wild birds in Missouri in the past, according to the CDC.

Federal officials this week added California, the country’s largest milk producer, to the list of states with infected cattle after three dairy herds tested positive for bird flu.

The CDC said its assessment of the risk to the general public remains low, but findings from its investigation into how the Missouri individual without obvious animal exposure contracted the virus will determine whether the agency needs to change its guidance.

Preliminary genetic analysis of the virus shows no evidence of changes that would make it more easily transmitted to humans, a federal health official said, speaking on the condition of anonymity because the investigation is ongoing.

“We haven’t seen evidence of any other type of respiratory illness” in the area where the individual lives, the official said.

The bird flu investigations typically involve detailed questionnaires about a person’s exposures to raw milk products, visits to state fairs or animal exhibits or zoos, and exposure to birds and bird feces, the official said.

CDC officials have stressed repeatedly that its national flu surveillance system would detect unusual influenza activity in people, including cases of H5N1. Since Feb. 25, more than 46,000 flu specimens have been tested for novel influenza viruses, including H5, according to the agency.


Missouri health officials said they are closely monitoring surveillance data. There has been no sign of unusual influenza activity among people such as upticks in emergency room visits or laboratory detection, according to a statement from Missouri’s Department of Health and Senior Services.


Fear at the fair, and the cows stay home. A story of bird flu and tradition.
August 17, 2024

Six Colorado workers contracted bird flu, the most human cases in a state
July 16, 2024


By Lena H. SunLena H. Sun is a national reporter for The Washington Post covering health with a special focus on public health and infectious disease. A longtime reporter at The Post, she has covered the Metro transit system, immigration, education and was a Beijing bureau chief. follow on X @bylenasun

 

H5N1 avian influenza virus found in multiple bird species in Antarctica

Birds in Antarctica. Credit: Ashley Bennison

A team of virologists with the U.K.'s Animal and Plant Health Agency, working with colleagues from the British Antarctic Survey, the KEMH Pathology and Food, Water & Environmental Laboratory, and the Department of Agriculture, both in the Falkland Islands, has found that the global spread of the H5N1 avian influenza virus has made its way to multiple bird species in Antarctica.

In their paper published in Nature Communications, the group describes how they tested multiple birds for the virus in the region over the years 2022–23 and what they learned by doing so.

The H5N1 avian influenza virus, as its name suggests, infects mainly birds, though it has been found to infect a few mammals, including humans. It was first observed in 1959 and then again in 1997. Early outbreaks were stopped by mass killing of animals in the infected areas.

More recently, infections have become widespread, infecting birds, both wild and domestic, across the globe. Billions of birds have been killed, thus far, and there is no indication that the pandemic is slowing. In this new effort, the researchers have found that the virus has even made its way to birds living in Antarctica—one place on the planet that is generally safe from such outbreaks.

The researchers traveled to several sub-Antarctic and Antarctic sites and tested birds that were living there, finding infected birds in all the places they visited. They also noted that the virus was infecting multiple species, ranging from Antarctic terns, to South Georgia shags, to brown skuas. They also found the virus had infected several marine mammals, such as the southern elephant seal.

In conducting a genetic analysis of the viruses they found, the research team was able to determine that the virus had spread to the sub-Antarctic (likely via migratory birds) from South America, and from there to Antarctica. The team also tested two penguins, one a king and the other a southern rockhopper, and found no evidence of infection.

The research team concludes by noting that it is not yet known what sort of impact the virus is having on bird populations in Antarctica, but that their work highlights the need for more research in the region.

More information: Ashley C. Banyard et al, Detection and spread of high pathogenicity avian influenza virus H5N1 in the Antarctic Region, Nature Communications (2024). DOI: 10.1038/s41467-024-51490-8

Journal information: Nature Communications© 2024 Science X Network

Chickens, ducks, seals and cows: A dangerous bird flu strain is knocking on Australia's door

Avian flu confirmed in three central California dairies


Three dairies in central California have tested positive for avian flu, the first time the virus has been discovered in the state after spreading across the United States since March. Image by Charlie Boyd from Pixabay

Aug. 31 (UPI) -- Three dairies in central California have tested positive for avian flu, the first time the virus has been discovered in the state after spreading across the United States since March.

On Friday, the California Department of Food and Agriculture confirmed the cases of the highly pathogenic avian influenza, or H5N1. The virus is fatal to poultry and makes cows mildly sick with symptoms of lethargy, loss of appetite and dehydration.

No human cases of HPAI have been confirmed in California related to this incident.

The risk to humans is considered low, according to California Department of Public Health and the Centers for Disease Control and Prevention. The total reported human cases are 14 since 2022, with four after exposure to dairy cows, according to the CDC. Nine of the H5 human cases have been confirmed as H5N1.

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The primary concern is for dairy workers in close contact with infected dairy cows.

Herds in California began showing clinical signs consistent with HPAI on Sunday.

Samples were submitted to the California Animal Health and Food Safety, and then to the National Veterinary Services Laboratory.

California State Veterinarian Dr. Annette Jones did not identify the county but said the 

The top three milk producers in the state are Tulare, Merced and Stanislaus counties. The state will also begin testing cows in nearby dairies and any poultry ranches for the avian flu, Jones said.

Jones said the affected dairies will be placed under quarantine, requiring enhanced bio-security measures, including wearing protective equipment and disinfecting equipment.

She said the healthy cows on the affected dairies have been cleared to continue shipping milk to processors for pasteurization to kill the virus and other harmful bacteria.

"This is a tough time for our dairy farmers given the economic challenges they're facing in a dynamic market, so I want to assure them that we are approaching this incident with the utmost urgency," CDFA Secretary Karen Ross said in a news release.

The virus was first reported in U.S. dairy cows on March 25 in Texas, most likely due to a single spillover event from wild birds. Since then it has been found in 13 states and has infected 192 herds.

Despite the low risk to humans, nearly 5 million doses of flu vaccine are being prepared for possible use in humans.

The avian virus has been detected in wild birds in the U.S. since 2022.

A study released in March found the bird flu is now jumping between species of mammals, a step that draws the virus closer to hopping into human beings.

Researchers have tracked transmission of avian influenza between dairy cows in herds, as well as from cows to cats and a raccoon.

Genetic analysis of the virus did not reveal any mutations that would lead to enhanced transmissibility of H5N1 in humans, said senior researcher Dr. Diego Diel, director of the Virology Laboratory at the Animal Health Diagnostic Center in the Cornell University College of Veterinary Medicine.