H5N1

Finland: Bird flu monitoring for all fur farms starts from minks

Via the Finnish Food Agency: Bird flu monitoring for all fur farms starts from minks. The Google translation:

At the beginning of September, the Finnish Food Agency will start bird flu monitoring for all fur farms. In the first phase of monitoring, the occurrence of the bird flu virus in minks from fur farms is investigated, because bird flu infections in minks pose a greater health risk to humans than bird flu infections in foxes and raccoons. Samples are taken from each of Finland's approximately 130 mink farms.  

Mink is a particularly problematic animal species when it comes to avian influenza virus infections. In the mink's upper respiratory tract, there are receptors that bind both bird and human influenza viruses, which is why mink are susceptible to infections caused by both types of influenza. The simultaneous infection of these viruses in mink can cause the emergence of a new type of virus variant, which may be more susceptible to infecting humans.  

The first phase of the monitoring is to be completed by the end of October, after which we will move on to the monitoring and sampling of the fox and raccoon kennels. Blood samples are taken from fur farms for antibody tests, and animals that have died or are euthanized by themselves are taken to detect the virus. Samples are taken by municipal veterinarians and samplers authorized by the Food Agency. The samples are examined in the Food Agency's laboratory. The samples are also examined for the presence of the coronavirus (SARS-CoV-2) at the same time.  

The infection was found in 25 fur farms  

The bird flu epidemic started in fur farms in Ostrobothnia in mid-July. The first infected fur farm was found in the Food Agency's laboratory tests on July 13, and since then bird flu infections have been confirmed at a total of 25 fur farms.  

For these shelters, shelter-specific reports on the infection situation have been made and a total of approximately 120,000 animals have been ordered to be euthanized. Termination orders have been issued to 13 shelters so far, and terminations are still ongoing in one shelter. In total, there are approximately 400 fur farms in Finland, which are estimated to have 1.3 million fur animals. After the autumn skinning, there are about 300,000 animals left in the shelters.  

In controlling animal disease epidemics, the most important thing is to identify animal farms where there are animals affected by the disease. In the monitoring of animal diseases, diseases are best found by examining sick or recently dead animals, because in them the infection is most likely to be active and the probability of finding the cause of the disease is also the highest. By killing infected and exposed animals, the infection pressure can be reduced in the most effective way.  

Monitoring of various animal diseases is carried out continuously at the Food Agency, and the need to expand the monitoring program is evaluated as necessary. Regarding bird flu, it has been decided to investigate all fur farms.

Eurosurveillance: Highly pathogenic avian influenza A(H5N1) virus infection on multiple fur farms in the South and Central Ostrobothnia regions of Finland, July 2023

Via Eurosurveillance, a report on the explosive spread of H5N1 in Finland: Highly pathogenic avian influenza A(H5N1) virus infection on multiple fur farms in the South and Central Ostrobothnia regions of Finland, July 2023. The introduction:

Highly pathogenic avian influenza (HPAI) A(H5N1) virus belonging to clade 2.3.4.4b has since the end of April 2023 caused widespread outbreaks in wild and domestic birds in 25 countries in Europe. In wild birds, black-headed gulls have been heavily affected, with mass deaths observed in many places, including in Finland. 

First reported on 14 July, an outbreak of avian influenza among farmed foxes, minks and raccoon dogs occurred in the regions of South and Central Ostrobothnia and is still ongoing. Up to 27 July, animals on 20 farms have been affected. Here, we provide an initial description of the outbreak and control measures taken, and discuss the source, potential reasons for and consequences of the outbreak.

The Finnish Food Authority is ordering all minks to be put down at fur farms with diagnosed avian influenza infections

Via the Finnish Food Authority: The Finnish Food Authority is ordering all minks to be put down at fur farms with diagnosed avian influenza infections.

The Finnish Food Authority has specified the euthanasia criteria for fur animals infected with avian influenza. The decision states that all minks will be put down at fur farms with diagnosed avian influenza infections. This policy decision on minks by the Finnish Food Authority also takes into account the view of the Finnish Institute for Health and Welfare (THL). The decisions to put down foxes and raccoon dogs will still be made on a case-by-case basis.  

Mink is an especially problematic species when it comes to avian influenza infections. This is due to the fact that minks’ upper respiratory tracts contain receptors that can bind to both avian and human influenza viruses, which makes minks sensitive to infections caused by both types of influenza. Minks can therefore be more effective than other mammals as an intermediate host for avian influenza, enabling the virus to mutate more effectively into a form that will infect humans. To prevent such variants of the virus, it is important to put down all minks at infected fur farms. 

With regard to decisions on putting down foxes and raccoon dogs, the Finnish Food Authority may order all or some of the foxes and raccoon dogs at a fur farm to be put down. This decision is impacted by the extent and intensity of the symptoms of avian influenza at the farm. It is also possible that no immediate euthanasia order will be issued for the animals at a farm if symptoms and increased mortality have stopped at the farm. 

However, the restrictions on fur farms imposed by the Regional State Administrative Agency and the measures to prevent the spread of the disease will remain in force at all the farms where avian influenza has been detected. If some animals at an infected farm have not been ordered to be put down, additional samples will be taken repeatedly from the animals at those farms to monitor the infection situation. Euthanasia decisions may be extended later on the basis of the results.  

Euthanasia order issued for three fur farms  

So far, the Finnish Food Authority has issued euthanasia orders for the animals of three fur farms. Preparations for new euthanasia orders are continuing this week. The Finnish Food Authority is not publishing information on the fur farms that have been issued euthanasia orders.  

Animal owners have the right to claim compensation from state funds for animals put down by an order issued by the Finnish Food Authority. The amount of compensation is still undetermined.  

Avian influenza had been diagnosed at twenty fur farms by the end of July. Samples from four farms are currently being analysed.

WHO: Ongoing avian influenza outbreaks in animals pose risk to humans

A WHO news release: Ongoing avian influenza outbreaks in animals pose risk to humans. Excerpt:

The current outbreaks of avian influenza (also called “bird flu”) have caused devastation in animal populations, including poultry, wild birds, and some mammals, and harmed farmers’ livelihoods and the food trade. Although largely affecting animals, these outbreaks pose ongoing risks to humans.   

The Food and Agriculture Organization of the United Nations (FAO), the World Health Organization (WHO), and the World Organisation for Animal Health (WOAH) are urging countries to work together across sectors to save as many animals as possible and to protect people.   

Avian influenza viruses normally spread among birds, but the increasing number of H5N1 avian influenza detections among mammals—which are biologically closer to humans than birds are—raises concern that the virus might adapt to infect humans more easily. In addition, some mammals may act as mixing vessels for influenza viruses, leading to the emergence of new viruses that could be more harmful to animals and humans.   

The goose/Guangdong-lineage of H5N1 avian influenza viruses first emerged in 1996 and has been causing outbreaks in birds since then. Since 2020, a variant of these viruses belonging to the H5 clade 2.3.4.4b has led to an unprecedented number of deaths in wild birds and poultry in many countries in Africa, Asia and Europe. In 2021, the virus spread to North America, and in 2022, to Central and South America.   

In 2022, 67 countries in five continents reported H5N1 high pathogenicity avian influenza outbreaks in poultry and wild birds to WOAH, with more than 131 million domestic poultry lost due to death or culling in affected farms and villages. In 2023, another 14 countries reported outbreaks, mainly in the Americas, as the disease continues to spread. Several mass death events have been reported in wild birds, caused by influenza A(H5N1) clade 2.3.4.4b viruses.   

Monitoring the recent surge in outbreaks among mammals  

Recently, there have been increasing reports of deadly outbreaks among mammals also caused by influenza A(H5)—including influenza A(H5N1)—viruses. 10 countries across three continents have reported outbreaks in mammals to WOAH since 2022. There are likely to be more countries where outbreaks have not yet been detected or reported.  

Both land and sea mammals have been affected, including outbreaks in farmed mink in Spain, seals in the United States of America, and sea lions in Peru and Chile, with at least 26 species known to have been affected. H5N1 viruses have also been detected in domestic animals such as cats and dogs in several countries, with recent detections of H5N1 in cats announced by authorities in Poland.  

“There is a recent paradigm change in the ecology and epidemiology of avian influenza which has heightened global concern as the disease spread to new geographical regions and caused unusual wild bird die-offs, and alarming rise in mammalian cases,” said Dr Gregorio Torres, Head of the Science Department at WOAH.  

Assessing the risk to humans  

Sporadic influenza A(H5N1) clade 2.3.4.4b virus detections in humans have also been reported, but remain very rare, with 8 cases reported since December 2021. Infections in humans can cause severe disease with a high mortality rate. The human cases detected thus far are mostly linked to close contact with infected birds and contaminated environments.   

"With the information available so far, the virus does not appear to be able to transmit from one person to another easily, but vigilance is needed to identify any evolution in the virus that can change that,” said Dr Sylvie Briand, Director of Epidemic and Pandemic Preparedness and Prevention, WHO.  

“WHO is working closely with FAO and WOAH, and laboratory networks to monitor the evolution of these viruses, looking for signals of any change that could be more dangerous to humans. We encourage all countries to increase their ability to monitor these viruses and to detect any human cases. This is especially important as the virus is now affecting countries with limited prior experience in avian flu surveillance."  

Studies are underway to identify any changes in the virus that may help the virus to spread more easily among mammals, including humans. 

ECDC: Enhanced surveillance of severe avian influenza virus infections in hospital settings in the EU/EEA

ECDC has published Enhanced surveillance of severe avian influenza virus infections in hospital settings in the EU/EEA. Click or tap through to download the PDF. The executive summary:

Avian influenza virus outbreaks are continuing during the summer months, causing mass mortality in sea-breeding bird colonies, including gulls. A larger exposure of human population to sick or dead birds and mammals is expected to occur. Transmission to humans cannot be excluded when avian influenza is circulating in wild birds and mammals and people are directly exposed without wearing protective equipment. 

During the summer months, infections with seasonal influenza viruses are considered to be very limited, and only a few patients with severe disease caused by the seasonal influenza virus are expected to be admitted to hospitals. 

 To identify sporadic severe human infections with avian influenza virus in hospital settings, the following approach is proposed: People admitted to hospitals with respiratory symptoms should be asked about exposure to birds (wild birds or poultry) or other wild animals (dead or alive) in the two weeks before admission. 

Consider testing for influenza virus hospitalised patients with unexplained viral encephalitis/ meningoencephalitis lacking the aetiological agent diagnosis. All influenza A-positive samples from hospitalised patients should be subtyped for seasonal influenza viruses A(H1)pdm09 and A(H3). Samples positive for influenza type A virus but negative for A(H1)pdm09 or A(H3) should be immediately sent to national influenza reference laboratories for further analysis and H5 testing.

Animal health body urges bird flu vaccination to avoid pandemic

Via Reuters: Animal health body urges bird flu vaccination to avoid pandemic. Excerpt:

PARIS, May 21 (Reuters) - Governments should consider vaccinating birds against bird flu to avoid the virus - which has already killed hundreds of millions of birds and infected mammals worldwide - turning into a new pandemic, the head of the World Animal Health Organisation (WOAH) said.  

The severity of the current outbreak of avian influenza, commonly called bird flu, and the economic and personal damage it has caused, has led governments to reconsider vaccinating poultry. However, some, like the United States, remain reluctant mainly because of the trade curbs this would entail.

"We are coming out of a COVID crisis where every country realised the hypothesis of a pandemic was real," WOAH Director General Monique Eloit told Reuters in an interview.  

"Since almost every country that does international trade has now been infected, maybe it's time to discuss vaccination, in addition to systematic culling which remains the main tool (to control the disease)," she said.  

The WOAH is holding a five-day general session from Sunday, and will be focus on global control of highly pathogenic avian influenza, or HPAI. 

A WOAH survey showed only 25% of its member states would accept imports of products from poultry vaccinated against HPAI.  

The European Union's 27 member states agreed last year to implement a bird flu vaccine strategy. France is set to be the first one, starting with ducks in the autumn.  

"If a bloc like the EU, which is a large exporter, starts moving in that direction, it will have a ricochet impact," Eloit said.  

The U.S. department of Agriculture (USDA) told Reuters on Friday that "in the interest of leaving no stone unturned in the fight against HPAI, USDA continues to research vaccine options that can protect poultry from this persistent threat".  

However, it still considers biosecurity measures to be the most effective tool for mitigating the virus in commercial flocks, it said in emailed answers.

Bird flu could become the next human pandemic – and politicians aren’t paying attention

Via The Guardian, an op-ed: Bird flu could become the next human pandemic – and politicians aren’t paying attention. Excerpt:

Since November, the signals emerging across the world continue to be worrying. In January and February this year, more than 3,000 sea lions died of bird flu in Peru (where the death toll in wild birds reached an estimated 50,000). In Russia, 700 Caspian seals died. Then several dolphins in Britain and the US died of H5N1. Normally, even if an animal catches H5N1 from a bird, it can’t pass it to other mammals. This limits its spread. But the large number of cases in these outbreaks suggest the possibility of mammal-to-mammal transmission, although this hasn’t been confirmed yet by genetic sequencing. A more likely hypothesis is that these outbreaks are groups of animals feeding on infected birds. It is not yet 100% clear what’s happening.  

But the risk of spread among mammals is ever-present. A new research pre-print from Canada showed that H5N1 samples could spread efficiently between ferrets with fatal outcomes. In order to spread efficiently to humans, H5 would need three major categories of genetic changes, according to bird flu expert Prof Richard Webby. So far, the virus has been able to make one of these changes, but not the other two. 

So right now, H5N1 is a theoretical risk for the next human pandemic, rather than one requiring urgency in response today. And a prime minister or health secretary might say, “Why prepare for something that might never happen?” 

To those of us scientists working in global health, there are enough concerning signals that action should already be happening. So that if a certain set of mutations do occur and we see an outbreak in humans in Peru or China or Britain, that the harm it could cause is minimal. This is a disease with an estimated 50-60% fatality rate in humans, including children.  

The cornerstone of infectious disease preparedness is in: surveillance (to know what strain is spreading and where in birds); testing (to identify disease quickly in humans); vaccines (for protection against disease and death); and antivirals (to improve clinical outcomes). The US government is already moving in this direction. Rebecca Katz, professor at Georgetown University Medical Center, has noted that a H5 candidate vaccine virus recently produced by the US Centers for Disease Control and Prevention is likely to provide good protection against the circulating H5N1 viruses.  

The information has been shared with vaccine manufacturers to start the process of stockpiling adequate doses. But this is a challenge because most influenza vaccines are created by incubating doses in chicken eggs (called egg-based production). If bird flu has killed off many of the chickens, then egg shortages are likely. There’s another H5N1 vaccine which is non-egg based, but they could have a maximum of 150m doses ready within six months. The world’s population is almost 8 billion.  

In addition, the FDA-approved antiviral treatments for seasonal influenza could also work against bird flu. But again, getting doses to all parts of the world is a challenge given shortages. Preparation must also involve appropriate PPE for healthcare workers to protect against a respiratory disease (flu) and diagnostics to quickly identify if someone is infectious in hospitals.  

All of these issues are solvable with precise planning, collaboration across countries, scientific ingenuity and good leadership. With post Covid-19 fatigue, the bigger problem is bringing the public along and communicating the facts so that they are trusted and believed. With so much – often understandable – mistrust in our current political leadership, authorities like chief medical officers and independent government advisers become crucial.

ECDC: Avian influenza overview March – April 2023

ECDC has published Avian influenza overview March – April 2023. The executive summary::

Poultry outbreaks occurred less frequently compared to the previous reporting period and compared to spring 2022. Most of these outbreaks were classified as primary outbreaks without secondary spread and some of them associated with atypical disease presentation, in particular low mortality. In wild birds, black-headed gulls continued to be heavily affected, while also other threatened wild bird species, such as the peregrine falcon, showed increased mortality. 

The ongoing epidemic in black-headed gulls, many of which breed inland, may increase the risk for poultry, especially in July-August, when first-year birds disperse from the breeding colonies. HPAI A(H5N1) virus also continued to expand in the Americas, including in mammalian species, and is expected to reach the Antarctic in the near future. 

HPAI virus infections were detected in six mammal species, particularly in marine mammals and mustelids, for the first time, while the viruses currently circulating in Europe retain a preferential binding for avian-like receptors. Since 13 March 2022 and as of 10 May 2023, two A(H5N1) clade 2.3.4.4b virus detections in humans were reported from China (1), and Chile (1), as well as three A(H9N2) and one A(H3N8) human infections in China.    

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, and low to moderate for occupationally or otherwise exposed people.

WHO DON: Human infection caused by avian influenza A (H5N1) - Chile

WHO has published Human Infection caused by Avian Influenza A (H5N1) - Chile. Excerpt:

Situation at a glance  

This Disease Outbreak News is an update on the report published on 6 April 2023 concerning human infection caused by avian influenza A(H5N1) in Chile. Since then, WHO received information on the results of genomic sequencing and the ongoing public health response.  

On 5 April, the results of genomic sequencing were completed by the Institute of Public Health of Chile (ISP per its acronym in Spanish), which is the National Influenza Centre (NIC) in Chile, which identified avian influenza virus A(H5N1) phylogenetic clade 2.3.4.4b. The genomic sequencing had 99.9% identity with H5 hemagglutinin sequences from Chilean birds, and complete neuraminidase (NA) had 100% identity with N1 sequences from Chilean birds.   

A total of 12 contacts (close contacts and healthcare workers) were identified. All tested negative for influenza and have completed the monitoring period. No further cases in Chile have been identified so far.  

Avian influenza infection in a human can cause severe disease and is notifiable under the International Health Regulations (IHR, 2005) [1]. 

Description of the case  

As reported previously, on 29 March 2023, the Ministry of Health of Chile notified WHO of the detection of human infection with avian influenza A(H5) virus.  

On 7 April 2023, the Chile International Health Regulations National Focal Point reported the results of genomic sequencing completed on 5 April 2023 by the NIC, which identified avian influenza A(H5N1) phylogenetic clade 2.3.4.4b.  

The patient is a 53-year-old male from the Region of Antofagasta in the north of Chile. He had no history of comorbidities or recent travel.  

On 13 March 2023, the patient developed symptoms including cough, sore throat, and hoarseness. On 21 March, due to worsening symptoms, he sought care at a local hospital. On 22 March 2023, the patient developed dyspnea and was admitted to a Regional Hospital at Antofagasta (SARI Sentinel Site). A nasopharyngeal swab sample was collected as part of routine severe acute respiratory infection (SARI) surveillance and tested negative for SARS-CoV-2 by reverse transcription-polymerase chain reaction (RT-PCR).  

On 23 March, the patient was admitted to the intensive care unit and treatment with antivirals (oseltamivir) and antibiotics was initiated. The patient remains in respiratory isolation under multidisciplinary management, with mechanical ventilation due to pneumonia. Standard infection control precautions were kept since the detection of the case.  

On 27 March, a bronchoalveolar sample was collected and tested positive for an unsubtypeable influenza A virus by PCR. The sample was sent to the ISP and tested positive for avian influenza A(H5) on 29 March. On 31 March, the NIC forwarded the patient's samples to a WHO Collaborating Centre for further characterization.   

On 5 April, the results of genomic sequencing were completed by the NIC in Chile, which identified avian influenza virus A(H5N1) phylogenetic clade 2.3.4.4b. The genomic sequencing had 99.9% identity with H5 hemagglutinin sequences from Chilean birds, and complete neuraminidase (NA) had 100% identity with N1 sequences from Chilean birds.   

Three close contacts of the case were identified, all asymptomatic, tested negative for influenza and have concluded the monitoring period. Additionally, a total of nine contacts among healthcare workers were identified, all tested negative for influenza and concluded the monitoring period on 4 April. However, on 5 April one of them developed respiratory symptoms, therefore a nasopharyngeal swab was taken, which tested negative for influenza; the monitoring period for this contact was extended for seven additional days, ending on 11 April.  

Avian influenza A (H5N1) was first detected in the Region of the Americas in birds in December 2014. Between December 2022 and February 2023, highly pathogenic avian influenza (HPAI) has been detected in wild aquatic birds (pelicans and penguins) and sea mammals (sea lions) in the Antofagasta Region where the case resides. According to preliminary findings of the epidemiological investigation of this human case, the most plausible route of transmission was through environmental exposure, given the large number of dead sea mammals and wild birds found in the area close to the patient´s residence.

Human infection caused by Avian Influenza A (H5) - Chile

A Disease Outbreak News item from WHO: Human infection caused by Avian Influenza A (H5) - Chile. Excerpt, with my bolding of part of a sentence:

Situation at a glance  

On 29 March 2023, the Ministry of Health of Chile notified WHO of a laboratory-confirmed case of human infection caused by avian influenza A(H5) virus in the Region of Antofagasta. This is the first human infection with avian influenza A(H5) virus reported in Chile and the third reported in the Region of the Americas to date. This is a single human infection and there is currently no evidence of the disease spreading among humans. An outbreak investigation is ongoing including determining the exposure of the case to the virus.  

In recent months of 2023, unprecedented outbreaks of highly pathogenic avian influenza (HPAI) A(H5N1) in animals have been reported from Chile. Avian Influenza A(H5N1) viruses have been detected among backyard poultry, farm poultry, wild birds, and sea mammals.  

Avian influenza infection in a human can cause severe disease and is notifiable under the International Health Regulations (IHR, 2005)[1].   

Description of the case  

On 29 March 2023, the Ministry of Health of Chile notified WHO of the detection of human infection with avian influenza A(H5) virus, confirmed by the Institute of Public Health of Chile (ISP per its acronym in Spanish), which is the National Influenza Centre. The patient is a 53-year-old male from the Region of Antofagasta in the north of Chile. He had no history of comorbidities or recent travel.  

On 13 March 2023, he developed symptoms including cough, sore throat, and hoarseness. On 21 March, due to worsening symptoms, he sought care at a local hospital. On 22 March 2023, the case developed dyspnea and was admitted to a Regional Hospital at Antofagasta. A nasopharyngeal swab sample was collected as part of routine severe acute respiratory infection (SARI) surveillance and tested negative for COVID-19 by reverse transcription-polymerase chain reaction (RT-PCR). On 23 March, he was admitted to the intensive care unit. On 24 March, treatment with antivirals (oseltamivir) and antibiotics was initiated. He remains in respiratory isolation under multidisciplinary management, with mechanical ventilation due to pneumonia.    

On 27 March, a bronchoalveolar sample was collected and tested positive for an unsubtypeable influenza A virus by RT-PCR. The sample was sent to the ISP and tested positive for avian influenza A(H5) on 29 March. The neuraminidase type is yet to be confirmed and the clade information for the avian influenza A(H5) virus detected in this human case is not yet known. The NIC has forwarded the patient's samples to a WHO Collaborating Centre for further characterization.   

Three close contacts of the case were asymptomatic and tested negative for influenza and have concluded the monitoring period. Additionally, a total of nine contacts among health care workers were identified, all concluded the monitoring on 4 April, however on 5 April one of them developed respiratory symptoms, therefore, further testing is ongoing, and the period of monitoring was extended for 7 more days for this contact of the case.  

Avian influenza A (H5N1) was first detected in the Americas in birds in December 2014. Between December 2022 and February 2023, highly pathogenic avian influenza (HPAI) was detected in wild aquatic birds (pelicans and penguins) and sea mammals (sea lions) in the Antofagasta Region where the case resides. According to preliminary findings of the epidemiological investigation of this human case, the most plausible route of transmission was through environmental exposure in areas close to the residence of the case where either sick or dead sea mammals or wild birds were found.