H5N1

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.

Scientists confirm first cases of bird flu on mainland Antarctica

Via The Guardian, very bad news: Scientists confirm first cases of bird flu on mainland Antarctica. Excerpt:

Bird flu has reached mainland of Antarctica for the first time, officials have confirmed.  

The H5N1 virus was found on Friday in two dead scavenging birds called skuas near Primavera Base, the Argentinian scientific research station on the Antarctic peninsula.  

Additional suspected cases have been reported in brown skua, south polar skua and kelp gull in Hope Bay, also on the Antarctic peninsula, according to data from the Scientific Committee on Antarctic Research.  

“This discovery demonstrates for the first time that the highly pathogenic avian influenza virus has reached Antarctica, despite the distance and natural barriers that separate it from other continents,” said a Spanish government report on Sunday.  

These are the first confirmed cases on the continent itself, which shows the virus is spreading in the region, most likely via migratory birds. This H5N1 outbreak is thought to have killed millions of wild birds globally since 2021, and has spread to every continent except Oceania.  

Avian flu reached the wider Antarctic region in October last year when it was reported on sub-Antarctic islands. The virus was first detected on the British overseas territory of South Georgia and the South Sandwich Islands, about 1,000 miles (1,600km) away from the continent of Antarctica. It was also found in the Falkland Islands, which is 600 miles north-west of South Georgia.

Initially it was reported in birds such as gulls, skuas and terns, but has since been found in albatross, penguins and southern fulmars. It has also spread to Antarctic mammals, with mass deaths of elephant seals and fur seals. The virus is also ripping through wildlife populations in the Arctic. In December, it was confirmed that the first polar bear had died of H5N1. “ 

There are many reports now of highly pathogenic avian influenza (HPAI) affecting several species in the Antarctic regions this season,” said Matthew Dryden from the UK Health Security Agency. “It may not have been reported on the Antarctic mainland until now because of the difficulties of accessing and sampling wildlife [there].”  

The dead birds from mainland Antarctica were found by Argentinian scientists and sent to scientists from the Centro de Biología Molecular Severo Ochoa in Madrid, who were working at the Spanish Antarctic base on Deception Island.  

“The problem is how long is it going to take before it transmits to other species like penguins. We need to monitor that,” said Antonio Alcamí, a researcher from the Spanish National Research Council who works at the Centro de Biología Molecular Severo Ochoa CSIC, who is based at the Spanish Antarctic base and tested the carcasses. “I’m afraid I think it probably will transmit into penguins. The skuas live pretty close, and so there are many opportunities for transmission, but we will see.”

Previous outbreaks in South Africa, Chile and Argentina have shown that penguins are susceptible to the virus. Since H5N1 arrived in South America, more than 500,000 seabirds have died of the disease, with penguins, pelicans and boobies among the most heavily affected.  

Researchers wrote in a pre-print research paper in November last year: “If the virus does start to cause mass mortality events across penguin colonies, it could signal one of the largest ecological disasters of modern times.”  

Diana Bell, the emeritus professor of conservation biology at the University of East Anglia, said the news was “sadly not surprising, given its previously reported presence on Antarctic islands in birds and elephant seals. It seems unlikely that the penguins there will not be infected.”

Bird flu set to spread in Antarctic causing huge damage, report says

Thanks to Mike Coston and FluTrackers for alerting me to this alarming report: Via Reuters: Bird flu set to spread in Antarctic causing huge damage, report says. Excerpt:

PARIS, Dec 21 (Reuters) - Bird flu is likely to spread further in the Antarctic region, causing immense damage to wildlife, according to experts on the highly contagious disease that has killed hundreds of millions of birds worldwide in recent years.  

The spread of highly pathogenic avian influenza (HPAI), commonly called bird flu, to the remote southern region has raised concerns for isolated populations of species including penguins and seals that have never been exposed to the virus.

The H5 strain of the virus was detected in the region on Oct. 8 in a brown skua on Bird Island, part of the British Overseas Territory of South Georgia and the South Sandwich Islands, according to a report by OFFLU, which gathers experts from the World Organisation of Animal Health (WOAH) and the U.N. Food and Agriculture Organisation (FAO).  

Around the same time, the virus was detected in fulmars and albatrosses in the nearby Falkland Islands.

"HPAI H5 virus is likely to spread further among Antarctic wildlife, potentially infecting the 48 species of birds and 26 species of marine mammals which inhabit this region," the OFFLU said in its report on Thursday.  

"The negative impact of HPAI H5 on Antarctic wildlife could be immense, because their presence in dense colonies of up to thousands of pinnipeds (seals) and hundreds of thousands of birds facilitates virus transmission and may result in high mortality," it added.

Elephant seals in South Georgia could have been infected by migrating seals from South America where there was a large die-off of the species, OFFLU said. Infected elephant seals could possibly transport the virus to neighbouring islands and further south to the Antarctic Peninsula.  

"If HPAI H5 virus completes the above-suggested stage of spread, further virus spread in the Antarctic region is likely given the many avian and mammalian species that probably are susceptible to infection," the report said.

52 commercial and backyard flocks in BC have been infected with bird flu

Via CBC News: 52 commercial and backyard flocks in B.C. have been infected with bird flu.

More than 50 poultry farms in British Columbia have been infected with avian flu since October, but animal health officials say that rate is slowing as the fall migration of wild birds ends. 

The Canadian Food Inspection Agency (CFIA) said Thursday 47 commercial farms and five small flocks have been infected with the highly pathogenic H5N1 virus this fall.  

B.C.'s Agriculture Ministry said in a news release that it is working with the agency and B.C.'s poultry producers to ensure enhanced biosecurity measures are in place to limit the spread of disease.  

If the flu is detected in a flock, all the birds on the farm must be destroyed. The CFIA said in November about five million birds in B.C. have been culled due to H5N1 since the first case was detected in April 2022. 

The ministry says avian flu poses a low risk to public health with no risk to food safety, and there are currently no poultry food supply disruptions due to the virus.  

The B.C. government introduced a $5-million farmed animal disease program this year that helps farmers enhance their biosecurity measures, equipment for disease response, research and training to better prevent the flu from entering the barns.

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.

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.

8 dead skunks found in Vancouver and Richmond test positive for H5N1 avian flu

Via CBC News, a story that's getting close to home: 8 dead skunks found in Vancouver and Richmond test positive for avian flu. Excerpt:

Eight skunks found dead last month in Vancouver and nearby Richmond, B.C., have tested positive for avian flu. 

The B.C. government says it is the same strain of avian influenza associated with the outbreak that began in April 2022.  

The skunks were found in residential areas in both cities and were taken to B.C.'s Animal Health Centre over concerns they may have been deliberately poisoned.  

British Columbia's Ministry of Agriculture says the skunks were infected with the same H5N1 strain that has caused the deaths of millions of domestic poultry since the outbreak began in April last year.  

The ministry says in a statement the skunks may have contracted H5N1 by scavenging on infected wild birds.  

The statement says while avian flu in skunks is considered to be a low risk to human health, there are always risks when people or pets come into contact with sick or dead wild animals.

Avian influenza overview December 2022 – March 2023

ECDC has published Avian influenza overview December 2022 – March 2023. The abstract:

Between 3 December 2022 and 1 March 2023 highly pathogenic avian influenza (HPAI) A(H5N1) virus, clade 2.3.4.4b, was reported in Europe in domestic (522) and wild (1,138) birds over 24 countries. An unexpected number of HPAI virus detections in sea birds were observed, mainly in gull species and particularly in black-headed gulls (large mortality events were observed in France, Belgium, the Netherlands, and Italy). The close genetic relationship among viruses collected from black-headed gulls suggests a southward spread of the virus. Moreover, the genetic analyses indicate that the virus persisted in Europe in residential wild birds during and after the summer months. 

Although the virus retained a preferential binding for avian-like receptors, several mutations associated to increased zoonotic potential were detected. The risk of HPAI virus infection for poultry due to the virus circulating in black-headed gulls and other gull species might increase during the coming months, as breeding bird colonies move inland with possible overlap with poultry production areas. 

Worldwide, HPAI A(H5N1) virus continued to spread southward in the Americas, from Mexico to southern Chile. The Peruvian pelican was the most frequently reported infected species with thousands of deaths being reported. The reporting of HPAI A(H5N1) in mammals also continued probably linked to feeding on infected wild birds. 

In Peru, a mass mortality event of sea lions was observed in January and February 2023. Since October 2022, six A(H5N1) detections in humans were reported from Cambodia (a family cluster with 2 people, clade 2.3.2.1c), China (2, clade 2.3.4.4b), Ecuador (1, clade 2.3.4.4b), and Vietnam (1, clade 2.3.4.4b), as well as two A(H5N6) human infections from China. 

The risk of infection with currently circulating avian H5 influenza viruses of clade 2.3.4.4b in Europe is assessed as low for the general population in the EU/EEA, and low to moderate for occupationally or otherwise exposed people.