H5N1

CDC Confirms First Severe Case of H5N1 Bird Flu in the United States

Via the CDC: CDC Confirms First Severe Case of H5N1 Bird Flu in the United States. Excerpt:

December 18, 2024-- A patient has been hospitalized with a severe case of avian influenza A(H5N1) virus ("H5N1 bird flu") infection in Louisiana. This marks the first instance of severe illness linked to the virus in the United States. The case was confirmed by the Centers for Disease Control and Prevention (CDC) on Friday, December 13. Since April 2024, there have been a total of 61 reported human cases of H5 bird flu reported in the United States.  

Partial viral genome data of the H5N1 avian influenza virus that infected the patient in Louisiana indicates that the virus belongs to the D1.1 genotype related to other D1.1 viruses recently detected in wild birds and poultry in the United States and in recent human cases in British Columbia, Canada, and Washington state. This H5N1 bird flu genotype is different than the B3.13 genotype detected in dairy cows, sporadic human cases in multiple states, and some poultry outbreaks in the United States. Additional genomic sequencing and efforts to isolate virus from clinical specimens from the patient in Louisiana are underway at CDC.  

While an investigation into the source of the infection in Louisiana is ongoing, it has been determined that the patient had exposure to sick and dead birds in backyard flocks. This is the first case of H5N1 bird flu in the U.S. that has been linked to exposure to a backyard flock.  

A sporadic case of severe H5N1 bird flu illness in a person is not unexpected; avian influenza A(H5N1) virus infection has previously been associated with severe human illness in other countries during 2024 and prior years, including illness resulting in death. No person-to-person spread of H5 bird flu has been detected. This case does not change CDC's overall assessment of the immediate risk to the public's health from H5N1 bird flu, which remains low.  

This case underscores that, in addition to affected commercial poultry and dairy operations, wild birds and backyard flocks also can be a source of exposure. People with work or recreational exposures to infected animals are at higher risk of infection and should follow CDC's recommended precautions when around animals that are infected or potentially infected with H5N1 avian influenza virus. This means that backyard flock owners, hunters and other bird enthusiasts should also take precautions.

California Acts to Protect Public Health: CDPH Warns Against Drinking Single Lot of Raw Milk Following Bird Flu Detection

Thanks to Helen Branswell and others for alerting me to this news release from the California Department of Public Health: California Acts to Protect Public Health: CDPH Warns Against Drinking Single Lot of Raw Milk Following Bird Flu Detection; Secures Voluntary Recall. Excerpt:

What You Need to Know: CDPH warns consumers not to drink one batch of cream top, whole raw milk from Raw Farm, LLC of Fresno County due to a detection of bird flu virus. Raw Farm, LLC issued a voluntary recall at the state’s request of the affected lot code 20241109 with a Best By date of 11/27/2024. Consumers should immediately return any remaining product to the store where it was purchased. Pasteurized milk remains safe to drink.

Sacramento –​ The California Department of Public Health (CDPH) today is warning the public to avoid consuming one batch of cream top, whole raw milk produced and packaged by Raw Farm, LLC of Fresno County due to a detection of bird flu virus in a retail sample. At the state’s request, the company has issued a voluntary recall of the affected raw milk with lot code 20241109 and Best By date of 11/27/2024 printed on the packaging.​ 

No illnesses associated with this lot of raw milk have been reported. Out of an abundance of caution, and due to the ongoing spread of bird flu in dairy cows, poultry, and sporadic human cases, consumers should not consume any of the affected raw milk. Customers should immediately return any remaining product to the retail point of purchase. CDPH is also notifying retailers to remove the affected raw milk from their shelves.​​   

The County of Santa Clara Public Health Laboratory has been testing raw milk products from retail stores as a second line of consumer protection. The county identified bird flu in one sample of raw milk purchased at a retail outlet. The testing was then verified by the California Animal Health and Food Safety Laboratory System.  

Risks Associated with Raw Milk  

Public health experts have long warned consumers against consuming raw milk or raw milk products due to elevated risks of foodborne illness. Outbreaks due to Salmonella, Listeria monocytogenes, toxin producing E. coli, Brucella, Campylobacter, and many other bacteria have all been reported related to consuming raw dairy products. Raw milk products are not pasteurized, a heating process that kills bacteria and viruses such as bird flu.   

Pasteurized milk and milk products are safe to consume because the heating process kills pathogens, including bird flu, that can cause illness.   

Drinking or accidentally inhaling raw milk containing bird flu virus may lead to illness. In addition, touching your eyes, nose, or mouth with unwashed hands after touching raw milk with bird flu virus may also lead to infection. Symptoms of bird flu infection in humans include eye redness or discharge, cough, sore throat, runny or stuffy nose, diarrhea, vomiting, muscle or body aches, headaches, fatigue, trouble breathing and fever. Anyone who has consumed these specific products, and is experiencing these symptoms, should immediately contact their health care provider or local health department. 

BC teen with avian flu is in critical condition, provincial health officer says

Via CBC News: B.C. teen with avian flu is in critical condition, provincial health officer says. Excerpt:

The teenager who tested positive for avian flu is in critical condition and being treated for acute respiratory distress at B.C. Children's Hospital, Provincial Health Officer Dr. Bonnie Henry says.  

Henry says the teen, the first presumptive human case of avian flu contracted in Canada, was admitted to hospital late Friday.  

Their condition "varied" over the weekend, Henry said, adding "our thoughts continue to be with this person and their family."  

Henry said work underway to confirm the diagnosis and trace potential sources of exposure through the B.C. Centre for Disease Control had given her "confidence" that the teen has H5 avian influenza, also known as bird flu.

She says it's likely that the teenager contracted the illness from exposure to an animal or the environment, although there's a "very real possibility" that the source will never be found.

Henry said privacy considerations restrict what can be said publicly about the teen, but said he or she did not have any underlying medical conditions.  

The teen first went to the emergency department on Nov. 2 and was tested and sent home, but returned to hospital days later when symptoms worsened.  

Henry said contact tracing has been conducted on 35 to 40 of the teen's family members, friends and acquaintances.  

"We have not identified anyone else that is sick with the virus in B.C. right now," she said. "We don't see right now that there's a risk of a lot of people getting sick."  

She said the teen was not in school during the infectious period of the disease, which roughly began on Oct. 31, two days before the onset of symptoms.  

She said the teen has no links to people who had recently travelled to Southeast Asia, which has seen outbreaks.  

According to Henry, the teen did not have any contact with birds but did interact with a variety of other animals —  including a dog, cats and reptiles — in the days before becoming ill. Henry said testing on those animals has so far been negative for the virus.  

She said no links have been found between the teen and local farms — including the two dozen B.C. poultry farms that have suffered avian flu outbreaks during the fall migration of wild birds. No links have been found to outbreaks taking place across the border in Washington state, she added.

Henry said the case is still being called a "presumptive positive" because it has to be confirmed at the National Microbiology Laboratory in Winnipeg, which could happen later on Tuesday.

First presumptive positive case of H5 avian influenza detected in BC

The BC provincial government published this news release today: First presumptive positive case of H5 avian influenza detected in BC. Excerpt and then a comment:

An individual in British Columbia has tested presumptive positive for avian influenza (also known as bird flu) caused by the H5 influenza virus, the first detection of avian influenza due to the H5 virus in a person in B.C.  

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 individual is a teenager from the Fraser Health region who is receiving care at BC Children’s Hospital. A public-health investigation has been initiated 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. “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.”  

Public health is following up with contacts who may have been exposed in order to assess for symptoms and provide guidance on testing and prevention measures. There have been no further cases identified at this time. The source of exposure is very likely to be an animal or bird, and is being investigated by B.C.’s chief veterinarian and public health teams.  

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, Office of the Chief Veterinarian, 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.

This is almost certainly H5N1, which has been turning up in the Fraser Valley for some time. If the teenager lives on a farm, the source of infection is almost certainly poultry. But it could have been through contact with a wild bird, or with a cat that had killed an infected wild bird. Or it could been contact with another human, though that seems unlikely. 

As far as I know, Canada has not yet reported H5N1 in dairy cattle. So the teenager may not have the mild symptoms now reported in dozens of American dairy workers: fever, pinkeye, and so on. 

So we will have to wait for more details, which our health authorities will take their time releasing. 

Detection and spread of high pathogenicity avian influenza virus H5N1 in the Antarctic Region

Via Nature Communications: Detection and spread of high pathogenicity avian influenza virus H5N1 in the Antarctic Region. The abstract:

Until recent events, the Antarctic was the only major geographical region in which high pathogenicity avian influenza virus (HPAIV) had never previously been detected. Here we report on the detection of clade 2.3.4.4b H5N1 HPAIV in the Antarctic and sub-Antarctic regions of South Georgia and the Falkland Islands, respectively. 

We initially detected H5N1 HPAIV in samples collected from brown skuas at Bird Island, South Georgia on 8th October 2023. Since this detection, mortalities were observed in several avian and mammalian species at multiple sites across South Georgia. Subsequent testing confirmed H5N1 HPAIV across several sampling locations in multiple avian species and two seal species. Simultaneously, we also confirmed H5N1 HPAIV in southern fulmar and black-browed albatross in the Falkland Islands. 

Genetic assessment of the virus indicates spread from South America, likely through movement of migratory birds. Critically, genetic assessment of sequences from mammalian species demonstrates no increased risk to human populations above that observed in other instances of mammalian infections globally. 

Here we describe the detection, species impact and genetic composition of the virus and propose both introductory routes and potential long-term impact on avian and mammalian species across the Antarctic region. We also speculate on the threat to specific populations following recent reports in the area.

Stop H5N1 influenza in US cattle now

An editorial in Science; Stop H5N1 influenza in US cattle now.

The relentless march of a highly pathogenic avian influenza virus (HPAIV) strain, known as H5N1, to become an unprecedented panzootic continues unchecked. The leap of H5N1 clade 2.3.4.4b from Eurasia and Africa to North America in 2021 and its further spread to South America and the Antarctic have exposed new avian and mammalian populations to the virus and led to outbreaks on an unrivaled scale. 

The virus has infected wild birds across vast geographic regions and caused wildlife deaths in some of the world’s most biodiverse ecosystems. Hundreds of millions of poultry have died or been culled, affecting global food security in some of the world’s poorest regions. Numerous mammalian species, including sea lions and fur animals, have been infected. Outbreaks in dairy cows in the United States have been occurring for months, seemingly unchecked in most affected states. Why is there not a greater sense of urgency to control these infections? 

Although the H5 2.3.4.4b virus seems poorly optimized for infection or spread in humans, with fewer than 20 cases since 2016, influenza leaves no room for complacency. The sheer number of infected wild birds and poultry has caused spillover infections to occur in wild carnivores, marine mammals, and farmed animals, providing additional pathways for exposure and perhaps infection in humans. The H5 virus has evolved continuously since 1996 but has never infected so many bird species nor been able to transmit to, and replicate in, cows. 

The more than 140 dairy farms in 12 US states with the virus and the detection of viral RNA in milk products in grocery stores speak for themselves. Infection in cattle creates new possibilities for direct contact between the virus and humans, and also risks the virus evolving the ability to spread in cattle, a new livestock reservoir of around 1.5 billion animals worldwide. 

Until now, human infections with H5 viruses were mainly associated with the keeping of infected poultry. But over the past 3 months, the United States has identified human H5 cases in farmworkers associated with one of the world’s most industrialized dairy production systems. Even difficult viral adaptations can occur if there are enough opportunities for contact and replication in new host species. Adaptation of the virus to cattle must be prevented. The outbreak in cattle in the United States must therefore be brought under control quickly. 

Key measures that should be initiated or intensified immediately include surveillance of all US dairy farms by testing, for example, bulk milk for influenza virus RNA, implementation of strict quarantine for infected cattle, and restriction of within-state transport to stop the circulation of the virus in cows. Only a couple of states are attempting this currently. 

Biosecurity and hygiene measures on US dairy facilities must be enhanced to avoid virus spread and spillover infections. This should include simple and practical steps such as keeping work clothing on the farm, thoroughly decontaminating stock vehicles and equipment, ensuring restricted access and movement of personnel among premises, and providing appropriate personal protective equipment. 

Human influenza surveillance should be bolstered during the summer and before the usual human seasonal influenza wave begins in the fall. The timely development of vaccine candidates for both livestock and humans should be undertaken along with associated policies on their distribution. This is the ultimate insurance against a worst-case scenario in which viral variants emerge that spread more easily in mammals. 

Globally, surveillance of mammalian cases should be intensified and real-time genomic information on the virus should be made publicly available, especially in at-risk populations (such as pig and fur animal farms). There must be increased global awareness of data collection and data sharing on zoonotic influenza. Analyses for incursion risk and pandemic preparedness based on both genetic and phenotypic data (including identifying mammalian adaptive changes, antiviral therapeutic resistance, and diagnostic robustness) in all regions need to be substantially improved, and the detection of human infection clusters needs to be further optimized. 

National and international coordination in the spirit of a modern “One Health” approach is essential, and the quadripartite comprising the Food and Agricultural Organization of the United Nations, United Nations Environment Programme, World Health Organization, and World Organisation for Animal Health should step up to take a leading role.

Cambodia: Two Takeo boys confirmed infected by H5N1 bird flu

Google Maps

Thanks to Peter O'Meagher for alerting me to this Khmer Times report: Two Takeo boys confirmed infected by H5N1 bird flu. Takeo is a province south of the capital, Phnom Penh. The 3-year-old case was reported yesterday, but not the 5-year-old. Excerpt:

The Takeo Health Department said two boys, ages three and five, have been confirmed to be infected with the H5N1 bird flu, while 29 others are still waiting for test results from the National Institute of Public Health (NIPH) and the Pasteur Institute (PI) of Cambodia.  

H5N1 is a subtype of influenza that predominantly infects birds. However, the H5N1 virus can also infect mammals that have been exposed to infected birds in some cases. In these cases, symptoms are frequently severe or fatal.  

Takeo Health Director Nhea Sithan said yesterday that two children have been diagnosed with the H5N1 bird flu virus, while 29 people were waiting on results of blood tests from the NIPH and PI. He said that the Takeo Provincial Health Department has asked experts to cooperate with the relevant ministries to identify everyone who ate chickens that are suspected of having been infected with the H5N1 bird flu virus.  

“We have dealt with the situation in a timely manner and we’ve sent 29 people who may have been exposed to H5N1 to analyse their blood to see whether they have contracted bird flu or not,” he said.  

The director of the Takeo Provincial Production and Veterinary Office, Thai Ly, said yesterday that more than 600 chickens that were thought to be at high risk of being infected with the H5N1 virus were destroyed after the Takeo Provincial Department of Agriculture, Forestry, and Fisheries identified a case of bird flu in Por village.  

He added that according to past studies of the bird flu virus, this level of infection is unlikely to spread to other villages. However, he urged people not to eat sick or already-dead birds to avoid H5N1 infection.  

“We are calling on people to be vigilant against infection by bird flu by not eating and cooking the chickens and ducks that are sick or die from unknown causes due to the danger caused by H5N1,” he said.

H5N1: International failures and uncomfortable truths

An editorial in The Lancet: H5N1: international failures and uncomfortable truths.

If you ask an infectious diseases specialist whether we should start worrying about influenza A H5N1, they will probably tell you that we should always be worrying about it. An influenza pandemic has long topped the list of global threats to health, and avian influenza poses a particularly serious concern. 

H5N1 has infected over 800 people since its identification in 1996, with a mortality rate exceeding 50%. Since 2020, it has become endemic in bird populations, triggering an unparalleled animal pandemic, affecting at least 26 mammal species. There is nothing new in influenza strains evolving, shifting their epidemiological habits, and causing infections in people, although human-to-human transmission of H5N1 is rare. 

Nonetheless, although developments over the past 3 months may or may not signal the start of a global pandemic, they are at the very least a pressing and unwelcome reminder of the caprices of zoonotic influenza and our continued collective complacency about it. 

An unprecedented outbreak of highly pathogenic avian influenza A(H5N1), the first documented infection in dairy cows, was reported on March 25, 2024 in Texas, Kansas, and New Mexico, raising the potential of cow-to-human transmission. Three confirmed human cases in the USA, all farm workers, have been reported so far, with the third person presenting with respiratory symptoms. 

Genetic analysis shows that the virus lacks changes that would make it better adapted to transmit between people and the risk to human health remains low, but it did detect adaptation to mammalian hosts. 

Despite calls for increased surveillance, the US response has been slow, with many cases likely going undetected. There has been resistance from the farming industry around testing and prevention, driven by a lack of awareness or understanding around changing practice and fear of trade restrictions and product loss. The US Department of Agriculture (USDA) and the US Centers for Disease Control and Prevention are incentivising dairy producers to supply personal protective equipment and offer laundering services for employees, but the USDA has been accused of being slow in sharing crucial virus sequence data, complicating our understanding of the outbreak. 

In Canada, early warning systems have been implemented to screen for H5N1 in milk. The UK says it has intensified its response to the US outbreak, but according to a report last month, it is not yet testing cows for the virus.

Action to curb this outbreak is needed urgently, including improving testing, surveillance, and reporting of infected animals and food products; vaccinating animal populations; transparent information sharing; developing and stockpiling human vaccine; and promoting protective measures among farm workers. All countries should build capacities to test, detect, and report infections, cases, and deaths above expected levels and share this information. Countries in need of external assistance to bolster their capacity should receive support.

 

The need for a robust and coordinated response to highly pathogenic avian influenza A(H5N1), as described in a Comment by Kojima and colleagues, serves to highlight the scale of the failure of countries to secure an international agreement on the pandemic accord. The 77th World Health Assembly, which closed on June 1, was meant to see a finalised draft of an international instrument on pandemic prevention, preparedness, and response. As The Lancet has noted, negotiations have been mired in disagreement and draft provisions have been unjust and inequitable (although changes to the International Health Regulations have been agreed). The process is not over yet—discussions continue with the hope of securing an agreement by May, 2025. Until then, the continued absence of a meaningful and effective accord undermines the ability to respond appropriately to international health threats, such as H5N1. Despite COVID-19, most countries are not prepared for a new pandemic.

 

Beyond the proximal drivers of outbreaks and potential interventions though, there is a need to confront an uncomfortable truth that the US H5N1 outbreak once again raises. Spillover of zoonoses into human populations stems ultimately from our ways of life and how they shape the human–animal interface. Our diets, our intensive farming practices, our livelihoods, our behaviours, and our cultures. Our exploitation of the natural world and our destruction of the environment. These issues are tractable through interdisciplinary education, intersectoral collaboration, adequate funding, and integrated policies. The concept of One Health, although often acknowledged, is rarely prioritised and operationalised. The result is a missed opportunity to not just respond to pandemic threats, but to prevent them altogether.

 

WHO: Avian Influenza A (H5N1) - Australia

A WHO DON: Avian Influenza A (H5N1) - Australia. Excerpt:

Situation at a glance  

On 22 May 2024, the World Health Organization (WHO) was notified of a laboratory-confirmed case of human infection with avian influenza A(H5N1) virus (clade 2.3.2.1a) by the International Health Regulations (IHR) National Focal Point (NFP) of Australia. This is the first confirmed human infection caused by avian influenza A(H5N1) virus detected and reported by Australia.  

Although the source of exposure to the virus in this case is currently unknown, the exposure likely occurred in India, where the case had travelled, and where this clade of A(H5N1) viruses has been detected in birds in the past. According to the IHR (2005), a human infection caused by a novel influenza A virus subtype is an event that has the potential for high public health impact and must be notified to the WHO. Based on available information, WHO assesses the current risk to the general population posed by this virus as low.  

Description of the situation  

On 17 May 2024, the WHO Collaborating Centre (WHO CC) for Reference and Research on Influenza in Australia notified the NFP of Australia of a suspected case of human A(H5N1) avian influenza (HPAI) in Melbourne, Victoria. The state Victorian Department of Health confirmed this case on 18 May 2024. Under Article 44, the NFP of Australia advised the NFP of India of the confirmed case on 21 May 2024. Under Article 8, the IHR NFP of Australia notified WHO of the case on 22 May 2024.  

The case is a 2.5-year-old female child with no underlying conditions.  She had a history of travel to Kolkata, India from 12 to 29 February 2024. She returned to Australia on 1 March 2024. Upon returning to Australia, the child presented at a hospital in Victoria on 2 March 2024, where she received medical care and was admitted on the same day. 

On 4 March, the patient was transferred to the intensive care unit at a referral hospital in Melbourne, Victoria, due to worsening symptoms, for a period of one week. The patient was discharged from hospital after a 2.5-week admission. The case is now reported to be clinically well.  

The Victorian Department of Health reported on 23 May 2024 that the family advised that the child started to feel unwell on 25 February 2024, with loss of appetite, irritability and fever, and was taken to a doctor on the evening of 28 February 2024 in India. She was febrile, coughing and vomiting and was given paracetamol. It was not reported to an Australian airport biosecurity officer that the child was unwell when she arrived in Australia on 1 March 2024.  

Additional information provided by the family indicates that the case did not travel outside of Kolkata, India, and did not have any known exposure to sick persons or animals while in India. It is understood that no close family contacts of the case in Australia or India developed symptoms, as of 22 May 2024.  

A nasopharyngeal swab and endotracheal aspirate taken on 6 and 7 March respectively tested positive for influenza A at the referral hospital. The samples were sent to the WHO CC for further characterisation on 3 April as part of a batch, as there was insufficient knowledge from the referring practitioners at the hospital to connect the case to the H5N1 virus.  

Virus genetic sequence obtained from the samples confirmed the subtype A(H5N1) and indicated that the haemagglutinin (HA) gene belonged to clade 2.3.2.1a, which circulates in South-East Asia and has been detected in previous human infections and in poultry.

Cows infected with bird flu have died in five US states

Via Reuters: Exclusive: Cows infected with bird flu have died in five US states. I sincerely hope that sick cows sent to slaughter do not then enter the food chain. Excerpt:

June 6 (Reuters) - Dairy cows infected with avian flu in five U.S. states have died or been slaughtered by farmers because they did not recover, state officials and academics told Reuters.  

Reports of the deaths suggest the bird flu outbreak in cows could take a greater economic toll in the farm belt than initially thought. Farmers have long culled poultry infected by the virus, but cows cost much more to raise than chickens or turkeys. 

A U.S. Department of Agriculture spokesperson said the agency knew of a few deaths but that the vast majority of cows recover well. Reuters was not able to determine the total number of cows with bird flu that died or were killed in South Dakota, Michigan, Texas, Ohio and Colorado.  

Avian flu has infected dairy cows in more than 80 herds across 10 states since late March, according to the USDA.  

Some of the animals died of secondary infections contracted after bird flu weakened their immune systems, said state veterinarians, agriculture officials, and academics assisting in state responses to bird flu. Other cows were killed by farmers because they failed to recover from the virus.  

Cattle infected with bird flu suffer reduced milk production, digestive issues, fever, and diminished appetite, according to farmers and veterinarians.  

In South Dakota, a 1,700-cow dairy sent a dozen of the animals to slaughter after they did not recover from the virus, and killed another dozen that contracted secondary infections, said Russ Daly, a professor with South Dakota State University and veterinarian for the state extension office who spoke with the farm. 

"You get sick cows from one disease, then that creates a domino effect for other things, like routine pneumonia and digestive issues," Daly said.  

A farm in Michigan killed about 10% of its 200 infected cows after they too failed to recover from the virus, said Phil Durst, an educator with Michigan State University Extension who spoke with that farm.