Avian influenza

Influenza caused by viruses adapted to birds

"Bird flu" redirects here. For the M.I.A. song, see Bird Flu.

For the H5N1 subtype of avian influenza, see Influenza A virus subtype H5N1.

Influenza (flu)

Types

* Avian
* A/H5N1 subtype
* Canine
* Equine
* Swine
* A/H1N1 subtype

Vaccines

* 2009 pandemic
* Pandemrix
* Live attenuated
* Seasonal flu vaccine brands

Treatment

* Amantadine
* Baloxavir marboxil
* Laninamivir
* Oseltamivir
* Peramivir
* Rimantadine
* Umifenovir
* Zanamivir

Pandemics

* 1889-1890 Russian flu
* 1918 Spanish flu
* 1957-1958 Asian flu
* 1968 Hong Kong flu
* 1977 Russian flu
* 2009 swine flu

Outbreaks

* 1976 swine flu
* 2006 H5N1 India
* 2007 Australian equine
* 2007 Bernard Matthews H5N1
* 2008 West Bengal
* 2015 United States H5N2 outbreak
* 2020–2023 H5N8 outbreak

See also

* Flu season
* Influenza evolution
* Influenza research
* Influenza-like illness
* Vaccine reformulations

* v
* t
* e

Avian influenza, also known as avian flu or bird flu, is a disease caused by the influenza A virus, which primarily affects birds but can sometimes affect mammals including humans.[1] Wild aquatic birds are the primary host of the influenza A virus, which is enzootic (continually present) in many bird populations.[2][3]

Symptoms of avian influenza vary according to both the strain of virus underlying the infection, and on the species of bird or mammal affected. Classification of a virus strain as either low pathogenic avian influenza (LPAI) or high pathogenic avian influenza (HPAI) is based on the severity of symptoms in domestic chickens and does not predict severity of symptoms in other species.[4] Chickens infected with LPAI display mild symptoms or are asymptomatic, whereas HPAI causes serious breathing difficulties, significant drop in egg production, and sudden death.[5] Domestic poultry may potentially be protected from specific strains of the virus by vaccination.[6]

Humans and other mammals can only become infected with avian influenza after prolonged close contact with infected birds.[7] In mammals including humans, infection with avian influenza (whether LPAI or HPAI) is rare.[citation needed] Symptoms of infection vary from mild to severe, including fever, diarrhea, and cough.[8]

Influenza A virus is shed in the saliva, mucus, and feces of infected birds; other infected animals may shed bird flu viruses in respiratory secretions and other body fluids (e.g., cow milk).[9] The virus can spread rapidly through poultry flocks and among wild birds.[9] A particularly virulent strain, influenza A virus subtype H5N1 (A/H5N1) has the potential to devastate domesticated poultry stocks and an estimated half a billion farmed birds have been slaughtered in efforts to contain the virus.[10]

## Highly pathogenic avian influenza

[edit]

Because of the impact of avian influenza on economically important chicken farms, a classification system was devised in 1981 which divided avian virus strains as either highly pathogenic (and therefore potentially requiring vigorous control measures) or low pathogenic. The test for this is based solely on the effect on chickens – a virus strain is highly pathogenic avian influenza (HPAI) if 75% or more of chickens die after being deliberately infected with it. The alternative classification is low pathogenic avian influenza (LPAI).[11] This classification system has since been modified to take into account the structure of the virus' haemagglutinin protein.[12] Other species of birds, especially water birds, can become infected with HPAI virus without experiencing severe symptoms and can spread the infection over large distances; the exact symptoms depend on the species of bird and the strain of virus.[11] Classification of an avian virus strain as HPAI or LPAI does not predict how serious the disease might be if it infects humans or other mammals.[11][13]

Since 2006, the World Organization for Animal Health requires all LPAI H5 and H7 detections to be reported because of their potential to mutate into highly pathogenic strains.[14]

## Virology

[edit]

Main article: Influenza A virus

A transmission electron micrograph (TEM) of the reconstructed 1918 pandemic influenza virus. The bottom structure represents membrane debris from the cells used to amplify the virus.[15]

Avian influenza is caused by the influenza A virus which principally affects birds but can also infect humans and other mammals.[16][17] Influenza A is an RNA virus with a genome comprising a negative-sense, RNA segmented genome that encodes 11 viral genes.[18] The virus particle (also called the virion) is 80–120 nanometers in diameter and elliptical or filamentous in shape.[19][20] There is evidence that the virus can survive for long periods in freshwater after being excreted in feces by its avian host, and can withstand prolonged freezing.[21]

There are two proteins on the surface of the viral envelope; hemagglutinin and neuraminidase.[4] These are the major antigens of the virus against which neutralizing antibodies are produced. Influenza virus epidemics and epizootics are associated with changes in their antigenic structure.[22]

Hemagglutinin (H) is an antigenic glycoprotein which allows the virus to bind to and enter the host cell. Neuraminidase (N) is an antigenic glycosylated enzyme which facilitates the release of progeny viruses from infected cells.[23] There are 18 known types of hemagglutinin, of which H1 thru H16 have been found in birds, and 11 types of neuraminidase.[16]

### Subtypes

[edit]

Subtypes of influenza A are defined by the combination of H and N proteins in the viral envelope; for example, "H5N1" designates an influenza A subtype that has a type-5 hemagglutinin (H) protein and a type-1 neuraminidase (N) protein.[7] The subtyping scheme only takes into account the two envelope proteins, not the other proteins coded by the virus' RNA. Almost all possible combinations of H (1 thru 16) and N (1 thru 11) have been isolated from wild birds.[24] Further variations exist within the subtypes and can lead to very significant differences in the virus's ability to infect and cause disease.[25]

### Influenza virus nomenclature

[edit]

Diagram of influenza nomenclature

To unambiguously describe a specific isolate of virus, researchers use the internationally accepted Influenza virus nomenclature,[26] which describes, among other things, the species of animal from which the virus was isolated, and the place and year of collection. As an example, A/chicken/Nakorn-Patom/Thailand/CU-K2/04(H5N1):[27]

* A stands for the genus of influenza (A, B or C)
* chicken is the animal species the isolate was found in (note: human isolates lack this component term and are thus identified as human isolates by default)
* Nakorn-Patom/Thailand is the place this specific virus was isolated
* CU-K2 is the laboratory reference number that identifies it from other influenza viruses isolated at the same place and year
* 04 represents the year of isolation 2004
* H5 stands for the fifth of several known types of the protein hemagglutinin
* N1 stands for the first of several known types of the protein neuraminidase.

Other examples include: A/duck/Hong Kong/308/78(H5N3), A/avian/NY/01(H5N2), A/chicken/Mexico/31381-3/94(H5N2), and A/shoveler/Egypt/03(H5N2).[28]

### Genetic characterization

[edit]

Analysis of the virus' genome enables researchers to determine the order of its nucleotides. Comparison of the genome of a virus with that of a different virus can reveal differences between the two viruses.[16][29] Genetic variations are important because they can change amino acids that make up the influenza virus’ proteins, resulting in structural changes to the proteins, and thereby altering properties of the virus. Some of these properties include the ability to evade immunity and the ability to cause severe disease.[29]

Genetic sequencing enables influenza strains to be further characterised by their clade or subclade, revealing links between different samples of virus and tracing the evolution of the virus over time.[29]

### Species barrier

[edit]

Humans can become infected by the avian flu if they are in close contact with infected birds. Symptoms vary from mild to severe (including death), but as of December 2024 there have been no observed instances of sustained human-human transmission.[4][17][30]

There are a number of factors that generally prevent avian influenza viruses from causing epidemics in humans or other mammals.[31][32][33]

* The viral HA protein of avian influenza binds to alpha-2,3 sialic acid receptors, which are present in the respiratory tract and intestines of avian species, while human influenza HA binds to alpha-2,6 sialic acid receptors, which are present in the human upper respiratory tract.[34][35]
* The myxovirus resistance protein (Mx1) is an important antiviral restriction factor that inhibits the replication of avian influenza viruses in particular. Human-adapted strains of IAV display reduced sensitivity to human Mx1 compared with avian strains.[31][36][32]
* Other factors include the ability to replicate the viral RNA genome within the host cell nucleus, and to transmit between individuals.[37]

Influenza viruses are constantly changing as small genetic mutations accumulate, a process known as antigenic drift. Over time, mutation may lead to a change in antigenic properties such that host antibodies (acquired through vaccination or prior infection) do not provide effective protection, causing a fresh outbreak of disease.[38]

The segmented genome of influenza viruses facilitates genetic reassortment. This can occur if a host is infected simultaneously with two different strains of influenza virus; then it is possible for the viruses to interchange genetic material as they reproduce in the host cells.[39] Thus, an avian influenza virus can acquire characteristics, such as the ability to infect humans, from a different virus strain. The presence of both alpha 2,3 and alpha 2,6 sialic acid receptors in pig tissues allows for co-infection by avian influenza and human influenza viruses. This susceptibility makes pigs a potential "melting pot" for the reassortment of influenza A viruses.[40]

## Epidemiology

[edit]

### History

[edit]

Avian influenza (historically known as fowl plague) is caused by bird-adapted strains of the influenza type A virus.[4] The disease was first identified by Edoardo Perroncito in 1878 when it was differentiated from other diseases that caused high mortality rates in birds; in 1955 it was established that the fowl plague virus was closely related to human influenza. In 1972, it became evident that many subtypes of avian flu were endemic in wild bird populations.[11]

Between 1959 and 1995, there were 15 recorded outbreaks of highly pathogenic avian influenza (HPAI) in poultry, with losses varying from a few birds on a single farm to many millions. Between 1996 and 2008, HPAI outbreaks in poultry have been recorded at least 11 times and 4 of these outbreaks have resulted in the death or culling of millions of birds.[11] Since then, several virus strains (both LPAI and HPAI) have become endemic among wild birds with increasingly frequent outbreaks among domestic poultry, especially of the H5 and H7 subtypes.

### Transmission and prevention

[edit]

The eight major flyways used by shorebirds (waders) on migration[41]

Pacific

Mississippi and Amazon

West Atlantic

East Atlantic

Mediterranean and Black Sea

West Asia and Africa

Central Asia and India

East Asia and Australasia

Sign in Central Park in New York City advising against handling birds

Birds – Influenza A viruses of various subtypes have a large reservoir in wild waterbirds of the orders Anseriformes (for example, ducks, geese, and swans) and Charadriiformes (for example, gulls, terns, and waders) which can infect the respiratory and gastrointestinal tract without affecting the health of the host.[42] They can then be carried by the bird over large distances, especially during annual migration. Infected birds can shed avian influenza A viruses in their saliva, nasal secretions, and feces; susceptible birds become infected when they have contact with the virus as it is shed by infected birds.[43] The virus can survive for long periods in water and at low temperatures, and can be spread from one farm to another on farm equipment.[44] Domesticated birds (chickens, turkeys, ducks, etc.) may become infected with avian influenza A viruses through direct contact with infected waterfowl or other infected poultry, or through contact with contaminated feces or surfaces.

Avian influenza outbreaks in domesticated birds are of concern for several reasons. There is potential for low pathogenic avian influenza viruses (LPAI) to evolve into strains which are high pathogenic to poultry (HPAI), and subsequent potential for significant illness and death among poultry during outbreaks. Because of this, international regulations state that any detection of H5 or H7 subtypes (regardless of their pathogenicity) must be notified to the appropriate authority.[45][46] It is also possible that avian influenza viruses could be transmitted to humans and other animals which have been exposed to infected birds, causing infection with unpredictable but sometimes fatal consequences.

When an HPAI infection is detected in poultry, it is normal to cull infected animals and those nearby in an effort to rapidly contain, control and eradicate the disease. This is done together with movement restrictions, improved hygiene and biosecurity, and enhanced surveillance. [44]

Humans – Avian flu viruses, both HPAI and LPAI, can infect humans who are in close, unprotected contact with infected poultry. Incidents of cross-species transmission are rare, with symptoms ranging in severity from no symptoms or mild illness, to severe disease that resulted in death.[47][46] As of February 2024 there have been very few instances of human-to-human transmission, and each outbreak has been limited to a few people.[48] All subtypes of avian Influenza A have potential to cross the species barrier, with H5N1 and H7N9 considered the biggest threats.[49][50]

In order to avoid infection, the general public are advised to avoid contact with sick birds or potentially contaminated material such as carcasses or feces. People working with birds, such as conservationists or poultry workers, are advised to wear appropriate personal protection equipment.[51]

Other animals – a wide range of other animals have been affected by avian flu, generally due to eating birds which had been infected.[52] There have been instances where transmission of the disease between mammals, including seals and cows, may have occurred.[53][54]

### Pandemic potential

[edit]

Influenza viruses have a relatively high mutation rate that is characteristic of RNA viruses.[55] The segmentation of the influenza A virus genome facilitates genetic recombination by segment reassortment in hosts who become infected with two different strains of influenza viruses at the same time.[56][57] With reassortment between strains, an avian strain which does not affect humans may acquire characteristics from a different strain which enable it to infect and pass between humans – a zoonotic event.[43] It is thought that all influenza A viruses causing outbreaks or pandemics among humans since the 1900s originated from strains circulating in wild aquatic birds through reassortment with other influenza strains.[58][59] It is possible (though not certain) that pigs may act as an intermediate host for reassortment.[60]

As of June 2024, there is concern about two subtypes of avian influenza which are circulating in wild bird populations worldwide, H5N1 and H7N9. Both of these have potential to devastate poultry stocks, and both have jumped to humans with relatively high case fatality rates.[61]

### Surveillance

[edit]

The Global Influenza Surveillance and Response System (GISRS) is a global network of laboratories that monitor the spread of influenza with the aim to provide the World Health Organization with influenza control information and to inform vaccine development.[62] Several millions of specimens are tested by the GISRS network annually through a network of laboratories in 127 countries.[63] As well as human viruses, GISRS monitors avian, swine, and other potentially zoonotic influenza viruses.

### Vaccines

[edit]

Poultry – it is possible to vaccinate poultry against specific strains of HPAI influenza. Vaccination should be combined with other control measures such as infection monitoring, early detection and biosecurity.[6][64]

Humans – Several "candidate vaccines" are available in case an avian virus acquires the ability to infect and transmit among humans. There are strategic stockpiles of vaccines against the H5N1 subtype, which is considered the biggest risk.[65][66][67] A vaccine against the H7N9 subtype, which has also infected humans, has undergone a limited amount of testing.[68] In the event of an outbreak, the "candidate" vaccine would be rapidly tested for safety as well as efficacy against the zoonotic strain, and then authorised and distributed to vaccine manufacturers.[64]

Zoonotic influenza vaccine Seqirus is authorized for use in the European Union.[69] It is an H5N8 vaccine that is intended to provide acquired immunity against H5 subtype influenza A viruses.[69]

In May 2025, the United States Department of Health and Human Services cancelled a $590 million contract with Moderna for the development of an mRNA bird flu vaccine, though Moderna indicated that it would seek other options to move forward, citing successful early clinical trials.[70]

### Influenza A virus subtype H5N1

[edit]

Influenza A subtype H5N1

* Influenza A virus
* subtype H5N1
* Genetic structure
* Infection
* Human mortality
* Global spread
* in 2004
* in 2005
* in 2006
* in 2007
* 2020–2025
* Social impact
* Pandemic
* Vaccine

* v
* t
* e

Further information: Influenza A virus subtype H5N1 and Transmission and infection of H5N1

The highly pathogenic influenza A virus subtype H5N1 is an emerging avian influenza virus that is causing global concern as a potential pandemic threat. It is often referred to simply as "bird flu" or "avian influenza", even though it is only one of many subtypes.

A/H5N1 has killed millions of poultry in a growing number of countries throughout Asia, Europe, and Africa. Health experts are concerned that the coexistence of human flu viruses and avian flu viruses (especially H5N1) will provide an opportunity for genetic material to be exchanged between species-specific viruses, possibly creating a new virulent influenza strain that is easily transmissible and lethal to humans.[71]

Influenza A/H5N1 was first recorded in a small outbreak among poultry in Scotland[72] in 1959, with numerous outbreaks subsequently in every continent.[73] The first known transmission of A/H5N1 to a human occurred in Hong Kong in 1997, when there was an outbreak of 18 human cases resulting in 6 deaths. It was determined that all the infected people had been exposed to infected birds in poultry markets. As the disease continued to spread among poultry flocks in the territory, the decision was made to cull all 1.6 million poultry in the area and to impose strict controls on the movement and handling of poultry. This terminated the outbreak.[74][75]

There is weak evidence to support limited human-to-human transmission of A/H5N1 in 139 outbreaks between 2005 and 2009 in Sumatra. The reproduction number was well below the threshold for sustained transmission.[76]

Between 2003 and February 2025, the World Health Organization has recorded 972 cases of confirmed H5N1 influenza, leading to 468 deaths.[77] The true fatality rate may be lower because some cases with mild symptoms may not have been identified as H5N1.[78]

### Influenza A virus subtype H7N9

[edit]

Further information: Influenza A virus subtype H7N9

Live poultry market in Xining, China, 2008

A significant outbreak of influenza A virus subtype H7N9 (A/H7N9) started in March 2013 when severe influenza affected 18 humans in China; six subsequently died.[79] It was discovered that a low pathogenic strain of A/H7N9 was circulating among chickens, and that all the affected people had been exposed in poultry markets. Further cases among humans and poultry in mainland China continued to be identified sporadically throughout the year, followed by a peak around the festival season of Chinese New Year (January and February) in early 2014 which was attributed to the seasonal surge in poultry production. Up to December 2013, there had been 139 cases with 47 deaths.[80]

Infections among humans and poultry continued during the next few years, again with peaks around the new year. In 2016 a virus strain emerged which was highly pathogenic to chickens.[81][82] In order to contain the HPAI outbreak, the Chinese authorities in 2017 initiated a large scale vaccination campaign against avian influenza in poultry. Since then, the number of outbreaks in poultry, as well as the number of human cases, dropped significantly. In humans, symptoms and mortality for both LPAI and HPAI strains have been similar.[81] Although no human H7N9 infections have been reported since February 2019, the virus is still circulating in poultry, particularly in laying hens. It has demonstrated antigenic drift to evade vaccines, and remains a potential threat to the poultry industry and public health.[82]

Genetic and evolutionary analyses have shown that the A(H7) viruses in the Chinese outbreak probably transferred from domestic duck to chicken populations in China and then reassorted with poultry influenza A(H9N2) to generate the influenza A(H7N9) strain that affected humans. The genetic characteristics of A(H7N9) virus are of concern because of their pandemic potential, e.g. their potential to recognise human and avian influenza virus receptors which affects the ability to cause sustained human-to-human transmission, or the ability to replicate in the human host.[79]

Between February 2013 and February 2019, there were 1,568 confirmed human cases and 616 deaths associated with the outbreak in China.[83][84] The majority of human cases have reported contact with poultry in markets or farms. Transmission between humans remains limited with some evidence of small family clusters. However, there is no evidence of sustained human-to-human transmission of A/H7N9 influenza.[81]

During early 2017, outbreaks of avian influenza A(H7N9) occurred in poultry in the USA. The strain in these outbreaks was of North American origin and is unrelated to the Asian lineage H7N9 which is associated with human infections in China.[81]

## Domestic animals

[edit]

Several domestic species have been infected with and shown symptoms of H5N1 viral infection, including cats, dogs, ferrets, pigs, chickens and turkeys.[85]

### Poultry

[edit]

Commercially important poultry species, including chickens, turkeys, and ducks, can be seriously affected by avian flu.[85][5] Low pathogenic strains (LPAI) may be controlled by vaccination.[86] An outbreak of a highly pathogenic strain (HPAI) on a poultry farm can lead to devastating consequences, including mortality rates approaching 100%, consequent economic losses, and potential risks to both animal and human health.[87] When a highly pathogenic strain (HPAI) is detected on a farm, the immediate response involves strict biosecurity measures and, in most cases, slaughter of the affected flock to prevent further spread.[88]. A general lack of genetic diversity in commercial poultry, which are often maintained in crowded conditions, makes them particularly vulnerable to avian flu.[89]

* Birds affected by highly pathogenic avian influenza (HPAI) could show swelling of the head, wattles, combs, and face. USDA photo.

* Purple discoloration of the comb could indicate highly pathogenic avian influenza (HPAI). USDA photo.

* Hemorrhaging of the skin and legs is just one of the signs birds might exhibit when infected with the highly pathogenic avian influenza (HPAI) virus. USDA photo.

* A chicken being tested for flu

### Dairy cows

[edit]

During April 2024, avian influenza was first detected in dairy cows in several US states and subsequently spread more widely through the year. Influenza A(H5N1) was found to be present at high levels in the mammary glands and in the milk of affected cows.[90][91][92] It was shown that the virus can persist on milking equipment, which provides a probable transmission route for cow-to-cow and cow-to-human spread.[93] A number of humans who had been in contact with cows tested positive for the virus, with mild symptoms.[94] According to CDC, 7% of 115 dairy workers had evidence of recent infection in a study from Michigan and Colorado from June to August 2024 – half of them asymptomatic. This is higher than estimates from prior transmission studies in poultry. All dairy workers had worked in cleaning the milk parlor and none had used personal protective equipment.[95]

In February 2025, a second type of avian flu, named D1.1, was confirmed in cattle in Nevada, besides the B3.13 circulating in cattle since late 2023, which has infected more than 950 herds in 16 states.[96] This new strain had been present in poultry and "more than a dozen people exposed to poultry" causing mild symptoms but was also found in a dairy worker in Churchill County, Nevada.[97]

### Cats

[edit]

This section is an excerpt from Avian influenza in cats.[edit]

Cats with avian influenza exhibit symptoms that can result in death. The avian influenza viruses cats may get include H5N1 or H7N2,[98] notable pathogenic subtypes of the virus. In order to get the virus, a cat would need to be in contact with infected waterfowl, poultry, or uncooked poultry.[99] Two of the main organs that the virus affects are the lungs and liver.[100] In May 2024, two indoor-only cats living in Michigan developed avian flu and died. Their owners were dairy farm workers who had symptoms of H5N1 bird flu before their cats, but did not want to be tested.[101]

## Global aspects

[edit]

### Global measures

[edit]

In 2005, the formation of the International Partnership on Avian and Pandemic Influenza was announced in order to elevate the importance of avian flu, coordinate efforts, and improve disease reporting and surveillance in order to better respond to future pandemics. New networks of laboratories have emerged to detect and respond to avian flu, such as the Crisis Management Center for Animal Health, the Global Avian Influenza Network for Surveillance, OFFLU, and the Global Early Warning System for major animal diseases. After the 2003 outbreak, WHO member states have also recognized the need for more transparent and equitable sharing of vaccines and other benefits from these networks.[102] Cooperative measures created in response to HPAI have served as a basis for programs related to other emerging and re-emerging infectious diseases.

### Impact on national policies

[edit]

HPAI control has also been used for political ends. In Indonesia, negotiations with global response networks were used to recentralize power and funding to the Ministry of Health.[103] In Vietnam, policymakers, with the support of the Food and Agriculture Organization of the United Nations (FAO), used HPAI control to accelerate the industrialization of livestock production for export by proposing to increase the portion of large-scale commercial farms and reducing the number of poultry keepers from 8 to 2 million by 2010.[104]

### Traditional Asian practices

[edit]

Backyard poultry production was viewed as "traditional Asian" agricultural practices that contrasted with modern commercial poultry production and seen as a threat to biosecurity. Backyard production appeared to hold greater risk than commercial production due to lack of biosecurity and close contact with humans, though HPAI spread in intensively raised flocks was greater due to high density rearing and genetic homogeneity.[105][106] Asian culture itself was blamed as the reason why certain interventions, such as those that only looked at place-based interventions, would fail without looking for multifaceted solutions.[104]

### Economic impact

[edit]

Avian influenza (AI), or bird flu, has significantly impacted the poultry industry with economic ramifications felt globally. The virus primarily affects poultry species, and when outbreaks occur, large-scale culling of infected birds is often necessary to prevent further spread. These measures disrupt egg production, causing supply shortages that directly lead to higher egg prices. For instance, during the 2022 avian influenza outbreaks, particularly in the U.S., millions of egg-laying hens were culled.[107] As egg production diminished, prices surged, placing a financial burden on consumers and businesses reliant on eggs for food production.[108] When egg prices increase, this low-cost source of animal proteins become less available to low-income consumers, making them the hardest hit.[109] In February 2025, to combat avian influenza, the USDA created a five-pronged strategy to combat highly pathogenic avian influenza and lower egg prices. This included strengthening biosecurity measures, expediting relief for farmers to accelerate repopulation, reducing regulatory burdens to expand supply and lower prices, investing $100 million in avian flu research and vaccine development, and exploring temporary import-export adjustments to stabilize supply. Through this, the New York wholesale egg prices that peaked at $8.53 per dozen steadily declined to $4.08 from 26 February, to 19 March 2025.[110]

Egg shortage at a local supermarket in Brooklyn, New York in February 2025, caused by the 2020–2025 H5N1 outbreak

Approximately 20% of the protein consumed in developing countries come from poultry.[105] A report by FAO totalled economic losses caused by avian influenza in South East Asia up to 2005 around US$10 billion. This had the greatest impact on small scale commercial and backyard producers.[111]

As poultry serves as a source of food security and liquid assets, the most vulnerable populations were poor, small scale farmers.[104] The loss of birds due to HPAI and culling in Vietnam led to an average loss of 2.3 months of production and US$69–108 for households where many have an income of $2 a day or less.[111] The loss of food security for vulnerable households can be seen in the stunting of children under five in Egypt. Women are another population at risk as in most regions of the world, small flocks are tended to by women. Widespread culling also resulted in the decreased enrollment of girls in school in Turkey.[105]

## See also

[edit]

* Influenza pandemic
* Influenza Genome Sequencing Project

## References

[edit]

1. ^ "Avian Influenza A H5N1 – United Kingdom of Great Britain and Northern Ireland". www.who.int. Retrieved 16 May 2024.
2. ^ Li YT, Linster M, Mendenhall IH, Su YC, Smith GJ (December 2019). "Avian influenza viruses in humans: lessons from past outbreaks". British Medical Bulletin. 132 (1): 81–95\. doi:10.1093/bmb/ldz036. PMC 6992886. PMID 31848585.
3. ^ Joseph U, Su YC, Vijaykrishna D, Smith GJ (January 2017). "The ecology and adaptive evolution of influenza A interspecies transmission". Influenza and Other Respiratory Viruses. 11 (1): 74–84\. doi:10.1111/irv.12412. PMC 5155642. PMID 27426214.
4. ^ a b c d "Avian Influenza in Birds". U.S. Centers for Disease Control and Prevention (CDC). 14 June 2022. Retrieved 6 May 2024.
5. ^ a b "Bird flu (avian influenza): how to spot and report it in poultry or other captive birds". Department for Environment, Food & Rural Affairs and Animal and Plant Health Agency. 13 December 2022. Retrieved 6 May 2024.
6. ^ a b "Vaccination of poultry against highly pathogenic avian influenza – Available vaccines and vaccination strategies". www.efsa.europa.eu. 10 October 2023. Retrieved 9 May 2024.
7. ^ a b "Influenza Type A Viruses". U.S. Centers for Disease Control and Prevention (CDC). 1 February 2024. Retrieved 3 May 2024.
8. ^ "Avian influenza: guidance, data and analysis". GOV.UK. 18 November 2021. Retrieved 9 May 2024.
9. ^ a b "Prevention and Antiviral Treatment of Bird Flu Viruses in People". U.S. Centers for Disease Control and Prevention (CDC). 19 April 2024.
10. ^ Bourk I (26 April 2024). "'Unprecedented': How bird flu became an animal pandemic". BBC. Retrieved 8 May 2024.
11. ^ a b c d e Alexander DJ, Brown IH (April 2009). "History of highly pathogenic avian influenza". Revue Scientifique et Technique. 28 (1): 19–38\. doi:10.20506/rst.28.1.1856. PMID 19618616.
12. ^ "Factsheet on A(H5N1)". www.ecdc.europa.eu. 15 June 2017. Retrieved 21 May 2024.
13. ^ "Current U.S. Bird Flu Situation in Humans". U.S. Centers for Disease Control and Prevention (CDC). 5 April 2024. Retrieved 22 May 2024.
14. ^ "National H5/H7 Avian Influenza surveillance plan". United States Department of Agriculture. Animal Plant Health Inspection Service. October 2013.
15. ^ "Recreated 1918 Influenza virions". U.S. Centers for Disease Control and Prevention (CDC). Archived from the original on 26 October 2020. Retrieved 24 April 2018.
16. ^ a b c "Types of Influenza Viruses". U.S. Centers for Disease Control and Prevention (CDC). 30 March 2023. Retrieved 23 March 2024.
17. ^ a b "Influenza (Avian and other zoonotic)". World Health Organization. 3 October 2023. Retrieved 6 May 2024.
18. ^ Samji T (December 2009). "Influenza A: understanding the viral life cycle". The Yale Journal of Biology and Medicine. 82 (4): 153–159\. PMC 2794490. PMID 20027280.
19. ^ Noda T (2011). "Native morphology of influenza virions". Frontiers in Microbiology. 2: 269. doi:10.3389/fmicb.2011.00269. PMC 3249889. PMID 22291683.
20. ^ Dadonaite B, Vijayakrishnan S, Fodor E, Bhella D, Hutchinson EC (August 2016). "Filamentous influenza viruses". The Journal of General Virology. 97 (8): 1755–1764\. doi:10.1099/jgv.0.000535. PMC 5935222. PMID 27365089.
21. ^ Shoham D, Jahangir A, Ruenphet S, Takehara K (4 October 2012). "Persistence of avian influenza viruses in various artificially frozen environmental water types". Influenza Research and Treatment. 2012: 912326. doi:10.1155/2012/912326. PMC 3471417. PMID 23091712.
22. ^ "Avian Influenza". NIOSH Workplace Safety and Health Topic. National Institute for Occupational Safety and Health. 17 October 2018.
23. ^ Couch RB (1996). "Orthomyxoviruses". Medical Microbiology (4th ed.). University of Texas Medical Branch at Galveston. ISBN 978-0-9631172-1-2. PMID 21413353.
24. ^ "FluGlobalNet – Avian Influenza". science.vla.gov.uk. Retrieved 5 June 2024.
25. ^ Eisfeld AJ, Neumann G, Kawaoka Y (January 2015). "At the centre: influenza A virus ribonucleoproteins". Nature Reviews. Microbiology. 13 (1): 28–41\. doi:10.1038/nrmicro3367. PMC 5619696. PMID 25417656.
26. ^ "A revision of the system of nomenclature for influenza viruses: a WHO memorandum". Bulletin of the World Health Organization. 58 (4): 585–591\. 1980. PMC 2395936. PMID 6969132. "This Memorandum was drafted by the signatories listed on page 590 on the occasion of a meeting held in Geneva in February 1980."
27. ^ CDC (27 September 2024). "Types of Influenza Viruses". U.S. Centers for Disease Control and Prevention (CDC). Retrieved 15 December 2024.
28. ^ Payungporn S, Chutinimitkul S, Chaisingh A, Damrongwantanapokin S, Nuansrichay B, Pinyochon W, et al. (April 2006). "Discrimination between highly pathogenic and low pathogenic H5 avian influenza A viruses". Emerging Infectious Diseases. 12 (4): 700–701\. doi:10.3201/eid1204.051427. PMC 3294708. PMID 16715581.
29. ^ a b c "Influenza Virus Genome Sequencing and Genetic Characterization". U.S. Centers for Disease Control and Prevention (CDC). 27 February 2024. Retrieved 24 May 2024.
30. ^ Lin TH, Zhu X, Wang S, Zhang D, McBride R, Yu W, et al. (6 December 2024). "A single mutation in bovine influenza H5N1 hemagglutinin switches specificity to human receptors". Science. 386 (6726): 1128–1134\. Bibcode:2024Sci...386.1128L. doi:10.1126/science.adt0180. PMID 39636969.
31. ^ a b Ciminski K, Chase G, Beer M, Schwemmle M (February 2021). "Influenza A Viruses: Understanding Human Host Determinants". Trends in Molecular Medicine. 27 (2): 104–112\. doi:10.1016/j.molmed.2020.09.014. PMID 33097424.
32. ^ a b Petric PP, Schwemmle M, Graf L (July 2023). "Anti-influenza A virus restriction factors that shape the human species barrier and virus evolution". PLOS Pathogens. 19 (7): e1011450. doi:10.1371/journal.ppat.1011450. PMC 10325056. PMID 37410755.
33. ^ Koçer ZA, Jones JC, Webster RG (December 2013). Atlas RM, Maloy S (eds.). "Emergence of Influenza Viruses and Crossing the Species Barrier". Microbiology Spectrum. 1 (2). doi:10.1128/microbiolspec.OH-0010-2012. PMID 26184958.
34. ^ Bertram S, Glowacka I, Steffen I, Kühl A, Pöhlmann S (September 2010). "Novel insights into proteolytic cleavage of influenza virus hemagglutinin". Reviews in Medical Virology. 20 (5): 298–310\. doi:10.1002/rmv.657. PMC 7169116. PMID 20629046. "The influenza virus HA binds to alpha 2–3 linked (avian viruses) or alpha 2–6 linked (human viruses) sialic acids presented by proteins or lipids on the host cell surface."
35. ^ Kuchipudi SV, Nelli RK, Gontu A, Satyakumar R, Surendran Nair M, Subbiah M (February 2021). "Sialic Acid Receptors: The Key to Solving the Enigma of Zoonotic Virus Spillover". Viruses. 13 (2): 262. doi:10.3390/v13020262. PMC 7915228. PMID 33567791.
36. ^ Ankerhold J, Kessler S, Beer M, Schwemmle M, Ciminski K (January 2025). "Replication Restriction of Influenza A(H5N1) Clade 2.3.4.4b Viruses by Human Immune Factor, 2023-2024". Emerging Infectious Diseases. 31 (1): 199–202\. doi:10.3201/eid3101.241236. PMC 11682815. PMID 39657579.
37. ^ Long JS, Mistry B, Haslam SM, Barclay WS (January 2019). "Host and viral determinants of influenza A virus species specificity". Nature Reviews. Microbiology. 17 (2): 67–81\. doi:10.1038/s41579-018-0115-z. PMID 30487536.
38. ^ "How Flu Viruses Can Change". U.S. Centers for Disease Control and Prevention (CDC). 12 December 2022. Retrieved 22 May 2024.
39. ^ Steel J, Lowen AC (2014). "Influenza a Virus Reassortment". Influenza Pathogenesis and Control - Volume I. Current Topics in Microbiology and Immunology. Vol. 385\. pp. 377–401\. doi:10.1007/82_2014_395. ISBN 978-3-319-11154-4. PMID 25007845.
40. ^ Schnitzler SU, Schnitzler P (December 2009). "An update on swine-origin influenza virus A/H1N1: a review". Virus Genes. 39 (3): 279–292\. doi:10.1007/s11262-009-0404-8. PMC 7088521. PMID 19809872. "If an avian virus mutates or reassorts and gains the ability to bind to α2,6 linked sialic acids, it might cross the species barrier and infect humans. Swine tissues express both forms of sialic acid and can be coinfected with human and avian viruses. Thus, pigs serve as a melting vessel for human, avian and swine influenza strains."
41. ^ Thompson D, Byrkjedal I (2001). Shorebirds. Colin Baxter Photography Ltd. ISBN 978-1841070759.
42. ^ "Mitigation strategy for avian influenza in wild birds in England and Wales". GOV.UK – Department for Environment Food & Rural Affairs. 18 March 2024. Retrieved 25 July 2024.
43. ^ a b "Transmission of Bird Flu Viruses Between Animals and People". U.S. Centers for Disease Control and Prevention (CDC). 15 May 2024. Retrieved 10 June 2024.
44. ^ a b "Avian Influenza". WOAH – World Organisation for Animal Health. Retrieved 10 June 2024.
45. ^ "Prevention and Control of H5 and H7 Avian Influenza in the Live Bird Marketing System". United States Department of Agriculture. August 2020. Retrieved 15 June 2024.
46. ^ a b "Questions and Answers on Avian Influenza". An official website of the European Commission. 11 June 2024. Retrieved 11 June 2024.
47. ^ "Avian Influenza A Virus Infections in Humans". U.S. Centers for Disease Control and Prevention (CDC). 30 May 2024. Retrieved 11 June 2024.
48. ^ "Reported Human Infections with Avian Influenza A Viruses". U.S. Centers for Disease Control and Prevention (CDC). 1 February 2024. Retrieved 11 June 2024.
49. ^ "Zoonotic influenza". World Health Organization. Retrieved 16 June 2024.
50. ^ "The next pandemic: H5N1 and H7N9 influenza?". Gavi, the Vaccine Alliance. Retrieved 16 June 2024.
51. ^ "Highly Pathogenic Avian Influenza A(H5N1) Virus in Animals: Interim Recommendations for Prevention, Monitoring, and Public Health Investigations". U.S. U.S. Centers for Disease Control and Prevention (CDC). 5 June 2024. Retrieved 13 June 2024.
52. ^ "Bird flu 'spills over' to otters and foxes in UK". BBC News. 2 February 2023. Retrieved 11 June 2024.
53. ^ "Study of H5N1 avian flu seal deaths reveals multiple lineages". Center for Infectious Disease Research and Policy. 15 March 2023. Retrieved 13 June 2024.
54. ^ Kozlov M (June 2024). "Huge amounts of bird-flu virus found in raw milk of infected cows". Nature. doi:10.1038/d41586-024-01624-1. PMID 38840011.
55. ^ Sanjuán R, Nebot MR, Chirico N, Mansky LM, Belshaw R (October 2010). "Viral mutation rates". Journal of Virology. 84 (19): 9733–9748\. doi:10.1128/JVI.00694-10. PMC 2937809. PMID 20660197.
56. ^ Kou Z, Lei FM, Yu J, Fan ZJ, Yin ZH, Jia CX, et al. (December 2005). "New genotype of avian influenza H5N1 viruses isolated from tree sparrows in China". Journal of Virology. 79 (24): 15460–15466\. doi:10.1128/JVI.79.24.15460-15466.2005. PMC 1316012. PMID 16306617.
57. ^ The World Health Organization Global Influenza Program Surveillance Network (October 2005). "Evolution of H5N1 avian influenza viruses in Asia". Emerging Infectious Diseases. 11 (10): 1515–1521\. doi:10.3201/eid1110.050644. PMC 3366754. PMID 16318689. Figure 1 shows a diagramatic representation of the genetic relatedness of Asian H5N1 hemagglutinin genes from various isolates of the virus
58. ^ Taubenberger JK, Morens DM (April 2010). "Influenza: the once and future pandemic". Public Health Reports. 125 (Suppl 3): 16–26\. doi:10.1177/00333549101250S305. PMC 2862331. PMID 20568566.
59. ^ Webster RG, Bean WJ, Gorman OT, Chambers TM, Kawaoka Y (March 1992). "Evolution and ecology of influenza A viruses". Microbiological Reviews. 56 (1): 152–179\. doi:10.1128/mr.56.1.152-179.1992. PMC 372859. PMID 1579108.
60. ^ "Factsheet on swine influenza in humans and pigs". European Centre for Disease Control. 15 June 2017. Retrieved 13 June 2024.
61. ^ "Global AIV with Zoonotic Potential". The Food and Agriculture Organization (FAO) of the United Nations. 29 July 2020. Retrieved 24 June 2024.
62. ^ Lee K, Fang J (2013). Historical Dictionary of the World Health Organization. Rowman & Littlefield. ISBN 9780810878587.
63. ^ "70 years of GISRS – the Global Influenza Surveillance & Response System". World Health Organization. 19 September 2022. Retrieved 13 June 2024.
64. ^ a b "Making a Candidate Vaccine Virus (CVV) for a HPAI (Bird Flu) Virus". U.S. Centers for Disease Control and Prevention (CDC). 3 June 2024. Retrieved 22 June 2024.
65. ^ "Vaccines for pandemic influenza". European Medicines Agency. Retrieved 15 June 2024.
66. ^ Keown A (4 February 2020). "FDA Approves Seqirus' Audenz as Vaccine Against Potential Flu Pandemic". BioSpace. Archived from the original on 5 February 2020. Retrieved 5 February 2020.
67. ^ "Audenz". U.S. Food and Drug Administration (FDA). 31 January 2020. STN: 125692. Archived from the original on 6 August 2020. Retrieved 5 February 2020. This article incorporates text from this source, which is in the public domain.
68. ^ Zheng D, Gao F, Zhao C, Ding Y, Cao Y, Yang T, et al. (14 September 2018). "Comparative effectiveness of H7N9 vaccines in healthy individuals". Human Vaccines & Immunotherapeutics. 15 (1): 80–90\. doi:10.1080/21645515.2018.1515454. PMC 6363152. PMID 30148691.
69. ^ a b "Zoonotic Influenza Vaccine Seqirus EPAR". European Medicines Agency (EMA). 9 October 2023. Retrieved 26 September 2024.
70. ^ Dillinger K (28 May 2025). "HHS cancels $590 million contract with Moderna for bird flu vaccine". CNN.
71. ^ Poovorawan Y, Pyungporn S, Prachayangprecha S, Makkoch J (July 2013). "Global alert to avian influenza virus infection: from H5N1 to H7N9". Pathogens and Global Health. 107 (5): 217–223\. doi:10.1179/2047773213Y.0000000103. PMC 4001451. PMID 23916331.
72. ^ "1880-1959 Highlights in the History of Avian Influenza (Bird Flu) Timeline". U.S. Centers for Disease Control and Prevention (CDC). 10 June 2024. Retrieved 14 July 2024.
73. ^ Weston P (26 March 2024). "'Cautious optimism' as penguins test positive for bird flu but show no symptoms". The Guardian. Retrieved 14 July 2024.
74. ^ Sencer DJ (2024). "Outbreak in Hong Kong, 1997 · Influenza: Complex Virus/Complex History · CDC Museum Digital Exhibits". CDC Museum. Retrieved 14 July 2024.
75. ^ "Recommendations for Worker Protection and Use of Personal Protective Equipment (PPE) to Reduce Exposure to Highly Pathogenic Avian Influenza A H5 Viruses : Avian Influenza (Flu)". U.S. Centers for Disease Control and Prevention (CDC). Retrieved 25 July 2015.
76. ^ Aditama TY, Samaan G, Kusriastuti R, Sampurno OD, Purba W, Santoso H, et al. (4 January 2012). "Avian influenza H5N1 transmission in households, Indonesia". PLOS ONE. 7 (1): e29971. Bibcode:2012PLoSO...729971A. doi:10.1371/journal.pone.0029971. PMC 3251608. PMID 22238686.
77. ^ "Global Influenza Programme : Avian influenza A(H5N1) virus". World Health Organization. 15 February 2025. Retrieved 28 March 2025.
78. ^ Li FC, Choi BC, Sly T, Pak AW (June 2008). "Finding the real case-fatality rate of H5N1 avian influenza". J Epidemiol Community Health. 62 (6): 555–9\. doi:10.1136/jech.2007.064030. PMID 18477756. S2CID 34200426.
79. ^ a b "Factsheet on A(H7N9)". European Centre for Disease Prevention and Control. 15 June 2017. Retrieved 15 July 2024.
80. ^ Li Q, Zhou L, Zhou M, Chen Z, Li F, Wu H, et al. (24 April 2013). "Preliminary Report: Epidemiology of the Avian Influenza A (H7N9) Outbreak in China". New England Journal of Medicine. 370 (6): 520–532\. doi:10.1056/NEJMoa1304617. PMC 6652192. PMID 23614499.
81. ^ a b c d "Risk assessment of avian influenza A(H7N9) – eighth update". UK Health Security Agency. 8 January 2020. Retrieved 15 July 2024.
82. ^ a b Liu Y, Chen Y, Yang Z, Lin Y, Fu S, Chen J, et al. (June 2024). "Evolution and Antigenic Differentiation of Avian Influenza A(H7N9) Virus, China". Emerging Infectious Diseases. 30 (6): 1218–1222\. doi:10.3201/eid3006.230530. PMC 11138980. PMID 38640498.
83. ^ "Avian Influenza A(H7N9) virus". Food and Agricultural Organization of the United Nations. 1 June 2022. Retrieved 15 July 2024.
84. ^ CDC (3 June 2024). "2010-2019 Highlights in the History of Avian Influenza (Bird Flu) Timeline". Avian Influenza (Bird Flu). Retrieved 16 July 2024.
85. ^ a b "Avian Influenza Wildlife Chart". USGS National Wildlife Health Center. 20 June 2016. Archived from the original on 6 February 2018.
86. ^ Thacker E, Janke B (February 2008). "Swine influenza virus: zoonotic potential and vaccination strategies for the control of avian and swine influenzas". The Journal of Infectious Diseases. 197 (Suppl 1): S19 – S24. doi:10.1086/524988. PMID 18269323.
87. ^ "The fight against bird flu". UK Collaborative on Development Research. Retrieved 25 June 2025.
88. ^ "Avian Influenza". WOAH - World Organisation for Animal Health. Retrieved 25 June 2025.
89. ^ Purdue University. "Commercial Poultry Lack Genetic Diversity, Are Vulnerable To Avian Flu And Other Threats." ScienceDaily. ScienceDaily, 12 November 2008. <www.sciencedaily.com/releases /2008/11/081103192314.htm>.
90. ^ Thomas P. "Bird Flu Spreads to Cattle, Raising Fears on Farms". WSJ. Archived from the original on 4 April 2024. Retrieved 4 April 2024.
91. ^ Burrough ER, Magstadt DR, Petersen B, Timmermans SJ, Gauger PC, Zhang J, et al. (July 2024). "Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Virus Infection in Domestic Dairy Cattle and Cats, United States, 2024". Emerging Infectious Diseases. 30 (7): 1335–1343\. doi:10.3201/eid3007.240508. PMC 11210653. PMID 38683888.
92. ^ Caserta L, Frye E, Butt S, Dimitrov K, Diel D (25 July 2024). "Spillover of highly pathogenic avian influenza H5N1 virus to dairy cattle". Nature. 634 (8034): 669–676\. Bibcode:2024Natur.634..669C. doi:10.1038/s41586-024-07849-4. PMC 11485258. PMID 39053575.
93. ^ Schnirring L (24 May 2024). "H5N1 avian flu viruses can persist on milking equipment surfaces". University of Minnesota. CIDRAP. Archived from the original on 23 May 2024. Retrieved 24 May 2024.
94. ^ Goodman B (8 October 2024). "As bird flu outbreak expands in California, dairy farms report it's worse than they expected". CNN. Retrieved 10 October 2024.
95. ^ Mellis AM, Coyle J, Marshall KE, Frutos AM, Singleton J, Drehoff C, et al. (7 November 2024). "Serologic Evidence of Recent Infection with Highly Pathogenic Avian Influenza A(H5) Virus Among Dairy Workers — Michigan and Colorado, June–August 2024". MMWR. Morbidity and Mortality Weekly Report. 73 (44): 1004–1009\. doi:10.15585/mmwr.mm7344a3. PMC 11542770. PMID 39509348.
96. ^ "Second type of bird flu detected in US dairy cows". 6 February 2025. Retrieved 21 February 2025.
97. ^ "New strain of bird flu is detected in a Nevada dairy worker, CDC says". 10 February 2025. Retrieved 21 February 2025.
98. ^ Lee CT (28 July 2017). "Outbreak of Influenza A(H7N2) Among Cats in an Animal Shelter With Cat-to-Human Transmission—New York City, 2016". Clinical Infectious Diseases. 65 (11): 1927–1929\. doi:10.1093/cid/cix668. PMID 29020187. Retrieved 16 May 2024.
99. ^ Thiry E, Addie, Diane, Belák, Sándor [in Hungarian], Boucraut-Baralon, Corine, Egberink, Herman, Frymus, Tadeusz [in Polish], et al. (1 July 2009). "H5N1 avian influenza in cats. ABCD guidelines on prevention and management". Journal of Feline Medicine & Surgery. 11 (7): 615–618\. doi:10.1016/j.jfms.2009.05.011. PMC 7128855. PMID 19481042.
100. ^ Marschall J, Hartmann K (1 August 2008). "Avian influenza A H5N1 infections in cats". Journal of Feline Medicine & Surgery. 10 (4): 359–365\. doi:10.1016/j.jfms.2008.03.005. PMC 10832898. PMID 18619884. S2CID 29347001.
101. ^ Naraharisetti R (February 2025). "Highly Pathogenic Avian Influenza A(H5N1) Virus Infection of Indoor Domestic Cats Within Dairy Industry Worker Households — Michigan, May 2024". MMWR. Morbidity and Mortality Weekly Report. 74 (5): 61–65\. doi:10.15585/mmwr.mm7405a2. Retrieved 21 February 2025.
102. ^ "Avian and Pandemic Influenza: The Global Response". Avian Influenza Action Group, United States Department of State. Oct 2008.
103. ^ Hameiri S (2014). "Avian influenza, 'viral sovereignty', and the politics of health security in Indonesia". The Pacific Review. 27 (3): 333–356\. doi:10.1080/09512748.2014.909523. S2CID 154302060.
104. ^ a b c Porter N (2012). "Risky zoographies: The limits of place in avian flu management". Environmental Humanities. 1 (1): 103–121\. doi:10.1215/22011919-3609994.
105. ^ a b c Alders R, Awuni JA, Bagnol B, Farrell P, de Haan N (2014). "Impact of avian influenza on village poultry production globally". EcoHealth. 11 (1): 63–72\. doi:10.1007/s10393-013-0867-x. PMID 24136383. S2CID 6701416.
106. ^ Porter N (2013). "Bird flu biopower: Strategies for multispecies coexistence in Viet Nam". American Ethnologist. 40 (1): 132–148\. doi:10.1111/amet.12010.
107. ^ Al Awaidy ST, Asghar RJ, Zaraket H (March 2024). "How Concerned Should We Be About the Recent Avian Influenza Outbreaks?". Oman Medical Journal. 39 (2): e604. doi:10.5001/omj.2024.86. ISSN 1999-768X. PMC 11229406. PMID 38978763.
108. ^ "Avian influenza outbreaks reduced egg production, driving prices to record highs in 2022". Economic Research Service. Retrieved 23 March 2025.
109. ^ Sumner D, Gow H, Hayes D, Matthews W, Norwood B, Rosen-Molina J, et al. (January 2011). "Economic and market issues on the sustainability of egg production in the United States: Analysis of alternative production systems". Poultry Science. 90 (1): 241–250\. doi:10.3382/ps.2010-00822. PMID 21177466.
110. ^ "USDA Update on Progress of Five-Pronged Strategy to Combat Avian Flu and Lower Egg Prices".
111. ^ a b McLeod A, Morgan N, Prakash A, Hinrichs J (2005). Economic and social impacts of avian influenza. Food and Agriculture Organisation (Report).

## Further reading

[edit]

Wikimedia Commons has media related to Avian influenza.

Wikinews has related news:

* Six-year-old Egyptian boy contracts bird flu

Wikinews has related news:

* Category:Avian Flu

* "The Science of Avian Flu, Answers to Nine Frequently Asked Questions". Discover Magazine Health & Medicine. 20 February 2006. pp. 59–61\. Archived from the original on 6 January 2016.
* Haugan S, Bjornson W, eds. (2009). Avian influenza: etiology, pathogenesis, and interventions. Hauppauge, New York: Nova Science Publishers. ISBN 978-1-60741-846-7.
* Seeger RM, Hagerman AD, Johnson KK, Pendell DL, Marsh TL (July 2021). "When poultry take a sick leave: Response costs for the 2014–2015 highly pathogenic avian influenza epidemic in the USA". Food Policy. 102: 102068. doi:10.1016/j.foodpol.2021.102068.

* v
* t
* e

Influenza

General topics|

* Research
* Vaccine
* Treatment
* Genome sequencing
* Reassortment
* Superinfection
* Flu season

Viruses|

* Orthomyxoviridae
* Influenza A
* Influenza B
* Influenza C
* Influenza D

Influenza A virus
subtypes

* H1N1
* H1N2
* H2N2
* H2N3
* H3N1
* H3N2
* H3N8
* H5N1
* H5N2
* H5N3
* H5N6
* H5N8
* H5N9
* H6N1
* H7N1
* H7N2
* H7N3
* H7N4
* H7N7
* H7N9
* H9N2
* H10N3
* H10N7
* H10N8
* H11N2
* H11N9

H1N1|

| Pandemics|

* 1918 (Spanish flu)
* 1977 (Russian flu)
* 2009 (Swine flu)

|

Science|

* 2009 A/H1N1

H5N1|

| Outbreaks|

* Croatia (2005)
* India (2006)
* UK (2007)
* West Bengal (2008)
* 2020s outbreak

|

Science|

* Genetic structure
* Transmission and infection
* Global spread
* Vaccine
* clinical trials
* Human mortality
* Social impact
* Pandemic preparation

H5N8|

| Outbreaks|

* 2020–2023

|

Treatments|

| Antiviral drugs|

* Adamantane derivatives
* Amantadine
* Rimantadine
* Neuraminidase inhibitor
* Oseltamivir
* Laninamivir
* Peramivir
* Zanamivir
* Peramivir (experimental)
* Umifenovir
* Baloxavir marboxil

|

Vaccines|

* Live attenuated influenza vaccine
* Brands
* Pandemrix
* Audenz

Immunostimulants|

* Cridanimod

Pandemics and
epidemics

| Pandemics|

* Influenza pandemic (1510)
* Influenza pandemic (1557)
* Russian flu (1889–1890)
* Spanish flu (1918)
* Asian flu (1957-1958)
* Hong Kong flu (1968)
* 1977 Russian flu
* Swine flu (2009)

|

Epidemics|

* Fujian flu (H3N2)
* 1989–1990 UK outbreak
* Central Luzon H5N6 (2017)

Non-human|

| Mammals|

* Canine
* Feline
* Equine
* 2007 Australian outbreak
* Swine

|

Non-mammals|

* Avian
* Fujian (H5N1)

Complications|

* Acute bronchitis
* Bronchiolitis
* Croup
* Otitis media
* Pharyngitis
* Pneumonia
* Sinusitis
* Strep throat

Related topics|

* Influenza-like illness
* 2017–2018 United States flu season
* US influenza statistics by flu season

* v
* t
* e

Infectious diseases – viral systemic diseases

Oncovirus|

DNA virus
HBV

Hepatocellular carcinoma
HPV

Cervical cancer
Anal cancer
Penile cancer
Vulvar cancer
Vaginal cancer
Oropharyngeal cancer
KSHV

Kaposi's sarcoma
EBV

Nasopharyngeal carcinoma
Burkitt's lymphoma
Hodgkin lymphoma
Follicular dendritic cell sarcoma
Extranodal NK/T-cell lymphoma, nasal type
MCPyV

Merkel-cell carcinoma

RNA virus
HCV

Hepatocellular carcinoma
Splenic marginal zone lymphoma
HTLV-I

Adult T-cell leukemia/lymphoma

Immune disorders|

* HIV
* AIDS

Central
nervous system|

| Encephalitis/
meningitis|

DNA virus
Human polyomavirus 2

Progressive multifocal leukoencephalopathy

RNA virus
MeV

Subacute sclerosing panencephalitis
LCV

Lymphocytic choriomeningitis
Arbovirus encephalitis
Orthomyxoviridae (probable)

Encephalitis lethargica

Rabies
Chandipura vesiculovirus
Herpesviral meningitis
Ramsay Hunt syndrome type 2

|

Myelitis|

* Poliovirus
* Poliomyelitis
* Post-polio syndrome
* HTLV-I
* Tropical spastic paraparesis

Eye|

* Cytomegalovirus
* Cytomegalovirus retinitis
* HSV
* Herpes of the eye

Cardiovascular|

* CBV
* Pericarditis
* Myocarditis

Respiratory system/
acute viral
nasopharyngitis/
viral pneumonia|

| DNA virus|

* Epstein–Barr virus
* EBV infection/Infectious mononucleosis
* Cytomegalovirus

|

RNA virus|

* IV: Human coronavirus 229E/NL63/HKU1/OC43
* Common cold
* MERS coronavirus
* Middle East respiratory syndrome
* SARS coronavirus
* Severe acute respiratory syndrome
* SARS-CoV-2
* COVID-19

* V, Orthomyxoviridae: Influenza virus A/B/C/D
* Influenza/Avian influenza

* V, Paramyxoviridae: Human parainfluenza viruses
* Parainfluenza
* Human orthopneumovirus
* hMPV

Human
digestive system|

| Pharynx/Esophagus|

* MuV
* Mumps
* Cytomegalovirus
* Cytomegalovirus esophagitis

|

Gastroenteritis/
diarrhea|

DNA virus
Adenovirus

Adenovirus infection

RNA virus
Rotavirus (Gastroenteritis)
Norovirus
Astrovirus
Coronavirus

Hepatitis|

DNA virus
HBV (B)

RNA virus
CBV
HAV (A)
HCV (C)
HDV (D)
HEV (E)

Pancreatitis|

* CBV

Urogenital|

* BK virus
* MuV
* Mumps

* v
* t
* e

Chicken

As poultry|

* As food
* Dishes
* Breeds
* Capon
* Poularde
* Poussin
* Broiler

Terminology|

* List of chicken colours
* List of poultry feathers

Husbandry|

* Battery cage
* Free range
* Furnished cages
* Yarding
* Chicken tractor
* Poultry farming
* Broiler industry
* Beak trimming
* Forced molting
* Hatchery
* Chick sexing
* Chick culling
* Chicken coop
* Chicken eyeglasses
* Chicken harvester
* Candling
* Abnormal behaviour in captivity
* European Union Council Directive 1999/74/EC

Culture|

* As pets
* Cockatrice
* Cockfighting
* Kapparos
* Sarimanok
* Gallic rooster
* Rooster Flag

Diseases|

* Aspergillosis
* Avian infectious laryngotracheitis
* Avian influenza
* Avian sarcoma leukosis virus
* Histomoniasis (blackhead disease)
* Botulism
* Campylobacteriosis
* Candidiasis
* Coccidiosis
* Colds
* Dermanyssus gallinae
* Egg binding
* Erysipelas
* Fatty liver hemorrhagic syndrome
* Fowlpox
* Gallid alphaherpesvirus 3
* Gapeworm
* Infectious bursal disease
* Infectious coryza
* Malaria
* Marek's disease
* Mycoplasmas
* Newcastle disease
* Omphalitis
* Psittacosis
* Pullorum
* Scaly leg
* Squamous cell carcinoma
* Tibial dyschondroplasia
* Toxoplasmosis

* v
* t
* e

Pandemics, epidemics and notable disease outbreaks

* List of epidemics and pandemics

Local|

| Ancient|

* Hittite plague (c. 1330 BC)
* Plague of Athens (429–426 BC)
* Antonine Plague (165–180 AD)
* Plague of Cyprian (250–266)

|

Post-
classical|

* Plague of Justinian (541–542)
* Roman Plague (590)
* Plague of Sheroe (627–628)
* Plague of Amwas (638–639)
* Plague of 664 (664–689)
* Japanese smallpox (735–737)
* Black Death (1346–1353)
* Sweating sickness (1485–1551)

Early
modern|

| 16th century|

* Influenza pandemic (1510)
* Mexican smallpox (1520)
* "Cocoliztli" epidemics in colonial Mexico (1545, 1576)
* Influenza pandemic (1557–1559)
* London plague (1563–1564)
* Maltese plague (1592–1593)
* London plague (1592–1593)

|

17th century|

* London plague (1603)
* Maltese plague (1623)
* Italian plague (1629–1631)
* Massachusetts smallpox (1633)
* Great Plague in the late Ming dynasty (1633–1644)
* Great Plague of Seville (1647–1652)
* Maltese plague (1655)
* Naples Plague (1656)
* Great Plague of London (1665–1666)
* Maltese plague (1675–1676)
* Great Plague of Vienna (1679)

18th century|

* Iceland smallpox epidemic (1707–1708)
* Great Northern War plague (1710–1712)
* Great Plague of Marseille (1720–1722)
* Great Plague of 1738 (1738)
* Russian plague (1770–1772)
* Persian Plague (1772)
* North American smallpox (1780–1782)
* Philadelphia yellow fever (1793–1798)

Modern|

| 19th century|

* Ottoman plague (1812–1819)
* Maltese plague (1813–1814)
* Caragea's plague (1813)
* Groningen epidemic (1829)
* Great Plains smallpox (1837–1838)
* Typhus (1847–1848)
* Copenhagen cholera (1853)
* Stockholm cholera (1853)
* Broad Street cholera (1854)
* Guam smallpox (1856)
* Pacific Northwest smallpox (1862–1863)
* Barcelona yellow fever (1870)
* Buenos Aires yellow fever (1871)
* Australia scarlet fever (1875–1876)
* Hong Kong plague (1894)

|

20th century|

* San Francisco plague (1900–1904)
* Manchurian plague (1910–1911)
* LA pneumonic plague (1924)
* Croydon typhoid (1937)
* NYC smallpox (1947)
* Wrocław smallpox (1963)
* Yugoslav smallpox (1972)
* London flu (1972–1973)
* Indian smallpox (1974)
* Surat plague (1994)
* Malaysian Nipah virus (1998–1999)

21st century|

* SARS (2002–2004)
* Midwest monkeypox (2003)
* Bird flu (2003–2005)
* Singaporean dengue (2005)
* Indian dengue (2006)
* Chikungunya outbreaks (2006)
* Pakistani dengue (2006)
* Iraqi cholera (2007)
* Zimbabwean cholera (2008–2009)
* Madagascar plague (2008–2017)
* Bolivian dengue (2009)
* Gujarat hepatitis (2009)
* Western African meningitis (2009–2010)
* Haiti cholera (2010–2019)
* Pakistani dengue (2011)
* Darfur yellow fever (2012)
* MERS (2012)
* Singaporean dengue (2013)
* Swansea measles (2013)
* Chikungunya (2013–2014)
* Western African Ebola (2013–2016)
* DR Congo Ebola (2014)
* Madagascar plague (2014)
* Odisha hepatitis (2014)
* Polio declaration (2014)
* Indian swine flu (2015)
* South Korean MERS (2015)
* Zika (2015–2016)
* Angolan yellow fever (2016)
* Yemeni cholera (2016–2022)
* Gorakhpur Japanese encephalitis (2017)
* Saudi Arabian MERS (2018)
* Kerala Nipah virus (2018)
* Équateur province Ebola (2018)
* Kivu Ebola (2018–2020)
* Madagascar measles (2018)
* Samoa measles (2019)
* Philippine measles (2019)
* Pacific NW measles (2019)
* New York measles (2019)
* Kuala Koh measles (2019)
* Tonga measles (2019)
* DRC measles (2019–2020)
* New Zealand measles (2019–2020)
* Singaporean dengue (2020)
* Uganda Ebola (2022–2023)
* Jamaica dengue (2023)
* Bangsamoro measles (2023–present)
* 2024 Latin American dengue
* Argentina (2024)

Global|

* First plague pandemic (541–767)
* Second plague pandemic (1348–19th century)
* Influenza pandemic (1510)
* Influenza pandemic (1557–1559)
* First cholera pandemic (1816–1826)
* Second cholera pandemic (1829–1851)
* Third cholera pandemic (1852–1860)
* Third plague pandemic (1855–1860)
* Fourth cholera pandemic (1863–1879)
* Fifth cholera pandemic (1881–1896)
* Russian flu (1889–1890)
* Sixth cholera pandemic (1899–1923)
* Spanish flu (1918–1920)
* encephalitis lethargica epidemic (1919–1930)
* Asian flu (1957–1958)
* Seventh cholera pandemic (1961–1975)
* Hong Kong flu (1968–1970)
* Russian flu pandemic (1977–1979)
* HIV/AIDS (1981–present)
* Swine flu (2009–2010)
* COVID-19 (2019–present)
* Mpox (clade II) outbreak (2022–2023)
* Mpox (clade Ib) epidemic (2023–2025)

Authority control databases

National|

* Germany
* United States
* France
* BnF data
* Czech Republic
* Israel

Other|

* Yale LUX

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