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.

WHO: Influenza A(H1N2)v-United States of America

A WHO DON: Influenza A(H1N2)v-United States of America. Excerpt:

Situation at a glance:  

On 4 August 2023, the United States International Health Regulations (IHR) National Focal Point informed PAHO/WHO of a human infection with a novel influenza A(H1N2) variant virus identified in the State of Michigan. This was confirmed by Reverse Transcription Polymerase Chain Reaction at the United States (US) Centers for Disease Control and Prevention (CDC) on August 2.  

The case was not hospitalized and is recovering from the illness. Investigations by local public health officials identified swine exposure by the patient at an agricultural fair.  

Additional public health response efforts including enhanced surveillance for cases is undergoing. Given the potential impact on public health, human infections with these viruses need to be monitored closely. In this event, there was no reported evidence of sustained human-to-human transmission, the illness was mild and no further influenza variant virus transmission in the community has been identified.  

Description of the case:  

On 4 August 2023, the United States IHR National Focal Point informed PAHO/WHO of a human infection with a novel influenza A(H1N2) variant virus identified in the State of Michigan and confirmed by the US CDC.   

According to the report, the case is under 18 years old, with no comorbidities, resident in the State of Michigan, who developed respiratory illness on 29 July 2023. The case presented with fever, cough, sore throat, muscle aches, headache, shortness of breath, diarrhea, nausea, dizziness, and lethargy. On 29 July, the case sought medical care at an emergency department, and an upper respiratory tract specimen was collected on 30 July. The specimen tested positive for influenza A virus on the same day. On 1 August, the patient received influenza antiviral treatment (Oseltamivir).  

On 31 July, the specimen was tested at the Michigan Department of Health and Human Services (MDHHS), and RT-PCR results were positive for influenza A virus but lacked reactivity with diagnostic tests for contemporary human influenza viruses representing either (H1) pdm09 or (H3) subtypes. The specimen was then sent to the US CDC for further testing and received on 2 August. On the same day, RT-PCR analysis of the specimen indicated an influenza A(H1N2) variant (v) virus. The virus was isolated and subsequent analysis including genetic sequencing is underway.  

The case was not hospitalized. Investigation by local public health officials identified swine exposure by the patient at an agricultural fair, that took place between 23 and 29 July, within 10 days prior to illness onset. Additional investigation did not identify respiratory illness in any of the patient’s close contacts or household contacts. No additional cases were identified related to this agriculture fair. No person-to-person transmission of influenza A(H1N2)v virus associated with this case has been identified. No additional cases of human infection with A(H1N2)v virus have been identified as of 10 August 2023.  

This is the first influenza A(H1N2)v virus infection identified in the United States this year. Since 2005, there have been 512 influenza A variant virus infections (all subtypes), including 37 (human infections with influenza A (H1N2)v viruses reported in the United States.

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: Influenza A(H5N1) in cats – Poland

A WHO DON, published July 16: Influenza A(H5N1) in cats – Poland. Excerpt:

Situation at a glance 

On 27 June 2023, the IHR National Focal Point of Poland notified WHO of unusual deaths in cats across the country. As of 11 July, 47 samples have been tested from 46 cats and one captive caracal, of which 29 were found to be positive for influenza A (H5N1). Fourteen cats are reported to have been euthanized, and a further 11 died, with the last death reported on 30 June. The source of the exposure of cats to the virus is currently unknown and epizootic investigations are ongoing.  

Sporadic infection of cats with A(H5N1) has previously been reported, but this is the first report of a high numbers of infected cats over a wide geographical area within a country.  

As of 12 July, no human contacts of A(H5N1) positive cats have reported symptoms, and the surveillance period for all contacts is now complete.  

The risk of human infections following exposure to infected cats at the national level is assessed as low for the general population, and low to moderate for cat owners and those occupationally exposed to H5N1-infected cats (such as veterinarians) without the use of appropriate personal protective equipment.  

WHO continues to monitor the situation and work in close collaboration with the animal and public health sectors, regional agencies, the Food and Agriculture Organization of the United Nations (FAO), the World Organisation for Animal Health (WOAH), and other partner agencies in Poland.  

Description of situation  

On 27 June 2023, the IHR National Focal Point of Poland notified WHO of unusual deaths in cats across the country. As of 11 July 2023, a total of 47 samples have been tested from 46 cats and one caracal (Caracal caracal). Of these 47 samples, 29 (62%) were positive for influenza A(H5N1). Positive samples were reported from 13 geographical areas within the country.  

Some cats developed severe symptoms including difficulty in breathing, bloody diarrhoea, and neurological signs, with rapid deterioration and death in some cases. In total, 20 cats had neurological signs, 19 had respiratory signs, and 17 had both neurological and respiratory signs.   

Fourteen cats are reported to have been euthanized, and a further 11 died.  Post-mortem exams on a small number of cats are suggestive of pneumonia. According to the information available, the last known death among cats was reported on 30 June.      

Genomic analysis of 19 viruses sequenced from this outbreak showed that they all belonged to the H5 clade 2.3.4.4b and were highly related to each other. Also, the viruses are similar to influenza A(H5N1) clade 2.3.4.4b viruses which have been circulating in wild birds and which caused outbreaks in poultry recently in Poland.   

The source of exposure of cats to the virus is currently unknown and epizootic investigations are ongoing. There are several possibilities for the source of infection, among which the cats could have had direct or indirect contact with infected birds or their environments, ate infected birds, or ate food contaminated with the virus. Authorities are investigating all potential sources and to date have not ruled out any. Of the 25 cats for which the information is available, two were outdoor cats, 18 were indoor with access to a balcony, terrace, or backyard, and five were indoor cats with no access to the outside environment. Seven cats are reported to have had the opportunity for contact with wild birds.   

This is the first report of high numbers of cats infected with avian influenza A(H5N1) spread over a wide geographical area within any country.  Sporadic infections in domestic cats with A(H5N1) viruses, including A(H5N1) H5 clade 2.3.4.4b viruses, have been reported previously, following close contact of the cats with infected birds or from ingesting meat of infected birds.

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. 

WHO: Influenza A(H1N1) variant virus - Brazil

Thanks to Mike Coston for tweeting about this WHO DON: Influenza A(H1N1) variant virus - Brazil. Excerpt:

On 7 June 2023, Brazil notified the World Health Organization (WHO) of a fatal laboratory-confirmed human case of infection with a swine-origin influenza A(H1N1) variant (v) virus in the inner state of Paraná.  

Sporadic human cases of influenza A(H1N1)v have been reported previously, including from Brazil. According to the International Health Regulations (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 the information currently available, WHO considers this a sporadic case, and there is no evidence of person-to-person transmission of this event. The likelihood of community-level spread among humans and/or international disease spread through humans is low.  

Description of the case  

On 7 June 2023, the Brazil IHR National Focal Point (NFP) notified WHO of a fatal human infection caused by a swine-origin influenza A(H1N1)v virus detected by the National Influenza Centre (NIC), Oswaldo Cruz Foundation, Rio de Janeiro.  

The patient was a 42-year-old woman with underlying medical conditions who lived near a swine farm. She developed fever, headache, sore throat, and abdominal pain on 1 May 2023 and was hospitalized on 3 May with a severe acute respiratory infection. On 4 May, the patient was admitted to the Intensive Care Unit (ICU) and she passed away on 5 May.  

Ongoing investigations reported that the patient did not have any direct contact with pigs, however, two of her close contacts worked at the swine farm. The two contacts did not develop respiratory disease and tested negative for influenza. To date, no human-to-human transmission associated with this case has been identified.   

During hospitalization, a nasopharyngeal swab sample was collected from the patient for influenza and SARS-CoV-2 testing, as part of regular respiratory virus surveillance activities. Real-time Polymerase Chain Reaction (RT-PCR) was conducted at the State of Paraná Central Public Health Laboratory, where the sample was subtyped as an influenza A/H1 virus. The sample also tested positive for a swine influenza A virus marker by RT-PCR.   

The specimen was forwarded to the National Influenza Centre Oswaldo Cruz Foundation, in Rio de Janeiro, where further complementary analyses and genomic sequencing were performed. Samples received at the NIC on 25 May were confirmed to be an influenza A(H1N1)v virus by sequence analysis on 30 May. The recovered genome has a high identity (99%) with the haemagglutinin (HA) of other Influenza A(H1N1)v viruses previously detected in the municipality of Toledo state of Paraná in 2022. In addition, it has 96% identity with the HA of viruses collected from pigs in Brazil in 2015.  

On 8 June, after the Brazilian Ministry of Health (MoH) notified WHO under the IHR, the NIC started the process to send the patient's samples to the WHO Collaborating Centre at the United States Centers for Disease Control and Prevention (US CDC) for further characterization. 

CHP closely monitors human case of avian influenza A(H5N6) in Mainland

Thanks to FluTrackers for alerting me to this report from the Hong Kong Centre for Health Protection: CHP closely monitors human case of avian influenza A(H5N6) in Mainland. Excerpt:

The Centre for Health Protection (CHP) of the Department of Health is today (June 5) closely monitoring a human case of avian influenza A(H5N6) in the Mainland, and again urged the public to maintain strict personal, food and environmental hygiene both locally and during travel.        

The case involves a 54-year-old female living in Nanchong, Sichuan, who had exposure to live domestic poultry before the onset of symptoms. She developed symptoms on May 19 and was admitted for treatment on the same day. She is in serious condition.        

From 2014 to date, 84 human cases of avian influenza A(H5N6) have been reported by Mainland health authorities.        

"All novel influenza A infections, including H5N6, are notifiable infectious diseases in Hong Kong," a spokesman for the CHP said.      

Travellers to the Mainland or other affected areas must avoid visiting wet markets, live poultry markets or farms. They should be alert to the presence of backyard poultry when visiting relatives and friends. They should also avoid purchasing live or freshly slaughtered poultry, and avoid touching poultry/birds or their droppings. They should strictly observe personal and hand hygiene when visiting any place with live poultry.      

Travellers returning from affected areas should consult a doctor promptly if symptoms develop, and inform the doctor of their travel history for prompt diagnosis and treatment of potential diseases. It is essential to tell the doctor if they have seen any live poultry during travel, which may imply possible exposure to contaminated environments. This will enable the doctor to assess the possibility of avian influenza and arrange necessary investigations and appropriate treatment in a timely manner.

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.