A strain of bird flu identified as H7N7 has been confirmed in Lancashire
The flu is not the same one that has ravaged the American poultry industry this year.
As the outbreak of avian bird flu H5N2 continues to trouble the American food industry — most recently resulting in the discontinuation of the beloved frozen custard at Rita’s Italian Ice — yet another strain of bird flu has been confirmed in Lancashire, England.
Given how quickly avian flu can spread, poultry owners in the region have been advised to be extremely vigilant about protecting their flocks, and an executive for the Royal Welsh Agricultural Society said that the biosecurity risk would be taken “extremely seriously.”
Stateside, the flu outbreak has forced the culling of several million birds across a number of states. It is unclear at this time how many birds in the U.K. have been affected by the strain, H7N7 — signs of which include respiratory distress and discoloration of the bird’s neck and throat.
Like H5N2, the strain of flu is contagious to birds, but the risk to humans is very low.
Case of Bird Flu Confirmed in United Kingdom - Recipes
The discovery of bird flu in turkeys at Redgrave Park Farm in Suffolk is the latest episode of the virus now affecting the UK.
In April 2006 a strain was found in chickens at a Norfolk farm and the month before that the deadly H5N1 strain was found in a dead swan on the Fife coast.
Below are the key developments in the UK so far:
10 January 2008 Three mute swans in Dorset are found dead with the virulent H5N1 strain of bird flu.
19 December 2007 All restrictions on bird gatherings and movements of poultry and poultry meat are lifted.
8 December 2007 Bird flu protection measures around the infected farms begin to be lifted.
23 November 2007 The national ban on bird shows and pigeon races, in place since 12 November, is lifted. Restrictions remain within the surveillance and protection zones in Suffolk and Norfolk.
21 November 2007 A further 68,000 birds are slaughtered on a sixth poultry farm in Suffolk in a bid to control the outbreak. The cull is more than double the other five combined.
19 November 2007 A case of the virulent H5N1 strain of bird flu is confirmed at Hill Meadow Farm, in Knettishall, Suffolk. The farm is near to Redgrave Park Farm where the outbreak began on 12 November.
16 November 2007 The outbreak forces organisers to axe the Royal Welsh Winter Fair, at Llanelwedd, for the second time in three years.
14 November 2007 A further 24,000 turkeys are slaughtered as a precaution on four premises run by the same company as that which operates the infected farm.
12 November 2007 About 5,000 birds slaughtered after the H5 strain of avian flu is confirmed in turkeys at Redgrave Park Farm, Suffolk. A 3km protection zone and a 10km surveillance zone are set up.
7 June 2007 The low pathogenic H7 strain of bird flu is found at a smallholding near St Helens in Merseyside.
27 May 2007 Following the death of chickens at a farm in Conwy, North Wales, the low pathogenic H7N3 strain is confirmed.
9 March 2007 Defra announces that all remaining control measures will be lifted at one minute past midnight on 12 March. Poultry movement and sale will now be allowed in the area. The UK's chief vet urges bird keepers to remain vigilant.
Bernard Matthews takes out full-page adverts in several newspapers, telling the public: "My turkey is completely safe to eat."
8 March 2007 Public Health Minister Caroline Flint reveals that 850 tons of turkey passed through the plant and into the food chain during the outbreak. Nearly 100 tons came from Hungary, she says, but the Food Standards Agency says none of the meat went near infected birds.
1 March 2007 The 3km exclusion zone around the plant is lifted, meaning turkeys no longer have to stay indoors. The wider 10km surveillance zone remains in place.
27 February 2007 Bernard Matthews lays off another 38 workers. It blames the move on a fall in demand.
Anti-viral drugs are offered to 480 workers and clean-up staff. The Health Protection Agency says it is a precautionary measure.
22 February 2007 The government announces that bird flu has not been found anywhere else in the UK.
20 February 2007 Market information company AC Nielsen says turkey sales have fallen by up to one third across the UK.
19 February 2007 At least 130 Bernard Matthews workers are to be laid off. The Transport and General Workers' Union say employees at Great Witchingham, Norfolk, will be stood down for 20 days from Tuesday, but the company refuses to confirm details.
Environment Secretary David Miliband says the disease inquiry is still focused on links to Hungary. He says restrictions in Suffolk will not be lifted before the second week of March and warns there is a "continual risk" of more outbreaks.
16 February 2007 Imported poultry from Hungary is the "most plausible" cause of the UK bird flu outbreak, government scientists say in a report.
They also list various failings at the Bernard Matthews plant in Suffolk where the outbreak started - including gulls carrying waste from the site.
15 February 2007 Bernard Matthews speaks out in defence of his company for the first time, saying allegations that information may have been withheld are "completely untrue".
14 February 2007 Some Bernard Matthews turkey products are cleared by the Food Standards Agency (FSA) to be released for sale.
13 February 2007 Scientists say the strains of H5N1 bird flu found in England and Hungary are "essentially identical", as the Suffolk farm at the centre of the UK outbreak resumes the slaughtering and processing of turkeys.
Also, the government gives the Holton plant the go-ahead to restart operations - poultry is brought in under a special licence that allows it to cross into the exclusion zone around the site.
11 February 2007 Environment Secretary David Miliband defends the government's handling of the outbreak. He says a ban on imports from Hungary, where the virus is thought to have originated, would have breached EU rules.
10 February 2007 Supermarkets deny there has been a slump in poultry sales after the outbreak.
9 February 2007 Bernard Matthews defends its import policy and says meat products it brought to the UK from Hungary came from outside the infected bird flu zone. The FSA confirms it is investigating whether meat infected with bird flu could have entered the food chain.
8 February 2007 The Suffolk outbreak may be linked to imports from the Bernard Matthews plant in Hungary, a government vet says. Culled birds from three more sheds on the Holton farm show strains of H5N1. But two more workers involved in dealing with the cull test negative for bird flu.
7 February 2007 A vet who became ill after working at Holton tests negative for bird flu.
6 February 2007 The cull of 159,000 turkeys is completed, the government announces.
4 February 2007 Government vets start gassing infected birds at the Holton farm.
3 February 2007 The European Commission says tests confirm that the avian flu is the H5N1 virus.
1 February 2007 Vets are called to the Bernard Matthews farm, in Holton, Suffolk. Early tests suggests the H5 strain of avian flu is responsible for the deaths of 2,600 turkeys.
26 April 2006 Chickens test positive for bird flu - early tests suggests the H7 strain - at a farm near Dereham, Norfolk, leading to the slaughter of 35,000 birds. The H7 strain is virulent among chickens but less of a risk to humans than the H5N1 strain.
22 April 2006 Protection zone affecting how poultry is kept within 3km of where the dead swan was found is lifted. The 10km surveillance zone, where movement of poultry products is restricted - and the broader risk area - remain in place until at least the end of the month.
20 April 2006 Scotland's first minister announces that restrictions imposed in the wake of the discovery of the dead swan are to be lifted.
11 April 2006 Dead bird identified as a whooper swan, not native to the UK, but scientists remain unsure whether it contracted the disease abroad or after it arrived in Britain.
6 April 2006 H5N1 is confirmed in the swan, and Scotland's contingency plan is put into effect. Tests on more birds are carried out.
5 April 2006 Laboratory tests confirm the presence of highly-pathogenic H5 avian flu in the dead swan. Further tests are carried out to establish whether it is the lethal H5N1 strain.
A two-day exercise to test the UK's bird flu plans is abandoned so that resources can be switched to the Scotland incident.
31 March 2006 Samples from the bird are received at the main testing laboratories in Weybridge, Surrey, for further analysis.
30 March 2006 The swan is collected and taken away for laboratory tests.
29 March 2006 A mute swan found dead in the harbour at Cellardyke, near Anstruther, Fife, is reported to the authorities.
15 November 2005 Subsequent tests show the disease is most likely to have come from the finches rather than the parrot. A government report blames the confusion on a mix-up of tissue samples.
21 October 2005 The lethal H5N1 strain is confirmed in one of the parrots, but because the bird was in quarantine, the discovery does not affect the UK's disease-free status.
14 October 2005 Some of the finches and parrots are found dead and tested for bird flu.
27 September 2005 A group of finches arrives at the same quarantine premises in Essex as part of a mixed consignment of birds from Taiwan.
19 September 2005 Department of Health publishes its latest pandemic flu contingency plan. Scotland issues its own updated plan.
16 September 2005 A consignment of parrots arrives in quarantine in Essex from Surinam, in South America.
Ebola virus disease – United Kingdom
On 29 December 2014, WHO was notified by the National IHR Focal Point for the United Kingdom of a laboratory-confirmed case of Ebola Virus Disease (EVD). This is the first EVD case to be detected on UK soil.
Details of the case are as follows:
The case is a female healthcare worker who has returned from volunteering at an Ebola treatment centre in Sierra Leone. The patient flew from Freetown to London via Casablanca, Morocco before reaching Glasgow on 28 December. The case displayed no symptoms of infectious Ebola throughout the journey, but is believed to have become febrile around the time of arrival to London.
After feeling unwell with fever and myalgia, the case was admitted to the specialist Brownlee Unit for Infectious Diseases on the Gartnavel Hospital campus in Glasgow and placed into strict isolation on the morning of 29 December. The patient was transferred for treatment in isolation at the Royal Free hospital in London on 30 December 2014. Currently, the patient is in stable condition and remains in isolation.
Public health response
A range of public health measures are being implemented by UK authorities with special attention to investigate all possible contacts with the patient during the flight to Scotland via Heathrow.
WHO is in close contact with UK authorities and is facilitating information sharing with involved countries, including Morocco. WHO is ready to further assist as needed.
Future WHO updates on EVD in the UK will not be posted on the Disease Outbreak News. Further information will be available in the WHO’s Ebola Situation Reports, which provide regular updates on the WHO response:
WHO does not recommend any travel or trade restrictions be applied by countries except in cases where individuals have been confirmed or are suspected of being infected with EVD or where individuals have had contact with cases of EVD. Contacts do not include properly-protected healthcare workers and laboratory staff.
Temporary recommendations from the Emergency Committee with regard to actions to be taken by countries can be found at:
Bird Flu Virus Confirmed In Farm On Scottish Borders
Poultry farmers in Scotland have been urged to boost security after a case of bird flu was confirmed.
The National Farmers Union (NFU) Scotland said the virus, thought to have been contracted from wild birds, was found in Scotland last week.
Tests confirmed the virus was present at a farm in the Scottish Borders.
While tests were taking place, officials put in place a ban on the movement of birds on and off the premises.
The union later confirmed the case has been dealt with and restrictions that had been put in place have been lifted.
No cull is understood to have been required.
In a statement, NFU Scotland said: &ldquoUrgent message for poultry keepers.
&ldquoLow pathogenic Avian Influenza (AI), thought to have been contracted from wild birds, was confirmed in a Scottish free range laying flock at the end of last week.
&ldquoPlease ensure highest levels of biosecurity at this time.&rdquo
Among recommended measures to promote biosecurity are cleaning and disinfecting vehicles and equipment that have come into contact with poultry and fencing off flocks to separate them from wild birds.
A spokesman for the union later added: &ldquoAlthough the case which is in the news has been dealt with, all restrictions lifted on the farm and should cause no alarm to egg producers or to consumers, it is pertinent time to remind all poultry keepers to adhere to the strict biosecurity requirements set out by the Scottish government to ensure Scottish eggs are of the highest quality, health and safety standards.
&ldquoAs the laboratory results confirmed a mild strain of non-notifiable avian influenza has been found, the restrictions on the site have now been lifted.
&ldquoAll the possible steps must be taken to ensure that poultry, and other captive birds, are protected against contact with wild birds.
&ldquoIt is important to avoid the transfer of contamination into and between premises and to minimise the movement of people, vehicles and equipment to areas where captive birds are kept.&rdquo
Bird owners are advised to perform regular health checks and report any signs of disease to a vet.
A Scottish government spokesman said: &ldquoWe are aware of a case of avian influenza on a premise in Scotland following routine investigations.
&ldquoLaboratory results have confirmed a mild strain of non-notifiable avian influenza has been found.
&ldquoGiven the results, the restrictions on the site have now been lifted.&rdquo
In December, all 27,000 birds at a commercial poultry farm in Suffolk were culled after a number were found to have the H5 strain of avian flu, identified as &ldquolow pathogenic&rdquo.
Avian Influenza Current Situation Summary
What to do if you find a dead bird
State and local agencies have different policies for collecting and testing birds, so check with your state health department, state veterinary diagnostic laboratory, or state wildlife agency for information about reporting dead birds in your area. Wildlife agencies routinely investigate sick or dead bird events if large numbers are impacted. This type of reporting could help with the early detection of illnesses like West Nile virus or avian influenza. If local authorities tell you to simply dispose of the bird&rsquos carcass (body), don&rsquot handle it with your bare hands. Use gloves or an inverted plastic bag to place the carcass in a garbage bag, which can then be disposed of in your regular trash.
To report unusual signs in birds you have seen in the wild, call 1-866-4-USDA-WS (1-866-4-8732-97).
- The U.S. poultry industry maintains rigorous health and safety standards, including routine monitoring for avian influenza.
- It is safe to eat properly handled and cooked poultry in the United States.
- However, consumers are reminded to handle raw poultry hygienically and cook all poultry and poultry products (including eggs) thoroughly before eating.
- Raw poultry can be associated with many infections, including salmonella.
- While there is no evidence that any human cases of avian influenza have ever been acquired by eating properly cooked poultry products, uncooked poultry and poultry products (like blood) have been linked to human infections with organisms other than influenza. Proper cooking kills influenza viruses. Visit the USDA food safety website at USDA &ndash Food Safety Education external icon for instructions on handling poultry safely.
Traveling to other countries
- Currently, CDC does not recommend any travel restrictions to any of the countries affected by avian influenza viruses in poultry or people.
- CDC does recommend that travelers to countries with avian influenza A outbreaks in poultry or people observe the following:
- Avoid visiting poultry farms, bird markets and other places where live poultry are raised, kept, or sold.
- Avoid preparing or eating raw or undercooked poultry products.
- Practice hygiene and cleanliness.
- Visit a doctor if you become sick during or after travel.
If you&rsquove had direct contact with infected birds
- should be watched if they become ill. They may be given influenza antiviral drugs to prevent illness.
- While antiviral drugs are most often used to treat flu, they also can be used to prevent infection in someone who has been exposed to influenza viruses. When used to prevent seasonal influenza, antiviral drugs are 70% to 90% effective.
- Close contacts (family members, etc.) of people who have been exposed to avian influenza viruses are being asked to monitor their health and report any flu-like symptoms.
- The U.S. Department of Interior (DOI) and the United States Department of Agriculture (USDA) are the lead federal agencies for outbreak investigation and control in wild birds and the USDA is the lead agency for such activities in domestic birds. CDC coordinates with DOI, USDA and with state health departments on appropriate public health measures and works with animal health colleagues to minimize the public health risk posed by avian influenza A viruses.
- In December 2014 and January 2015, the United States Department of Agriculture&rsquos (USDA) Animal and Plant Health Inspection Service (APHIS) reported the presence of highly pathogenic avian influenza (HPAI) H5N2 and HPAI H5N8 viruses in wild birds pdf icon [156 KB, 3 pages] external icon in a few states. The initial findings were a result of increased outreach, reporting and surveillance activities following the detection of HPAI H5N2 among commercial flocks in Canada external icon reported in early December 2014. Two of these viruses were then detected commercial poultry in the United States.
- In January 2015, an HPAI* H5N1 virus was detected in a wild duck in the United States. The H5N1 virus isolated from a U.S. wild bird was a new mixed virus (a reassortant) that was genetically different from the Asian avian H5N1 viruses that have caused human infections associated with high mortality in several other countries (notably in Asia and Egypt).
- CDC considers the risk to people from these HPAI infections in wild birds to be low, but has developed interim guidance on testing and chemoprophylaxis. For more information, see the &ldquoProtective Actions You Can Take&rdquo tab at the top of this page.
- No human infections with these viruses have been detected at this time. However, similar viruses have infected people in the past. It&rsquos possible that human infections with these viruses may occur.
- Since December 2003, Asian-lineage highly pathogenic avian influenza (HPAI) A(H5N1) viruses have caused high mortality in infected poultry and wild birds in Asia, the Middle East, Europe and Africa.
- Millions of poultry have been culled to control the spread of HPAI H5N1 viruses.
- Outbreaks of HPAI H5N1 virus have also occurred among poultry in non-endemic countries.
- Outbreaks of HPAI H5N1 virus among poultry continue to occur in some countries.
H7 viruses (HPAI and LPAI):
- There have been outbreaks of HPAI H7 viruses identified in poultry in various countries, including Mexico, the Netherlands, Chile and Canada. Sporadic cases of human infection with these viruses have been identified.
- Since 2013, Asian lineage LPAI A(H7N9) viruses in China have been detected in poultry or live poultry markets in eastern, southern and northern China. LPAI H7N9 virus infection does not generally cause observable illness in poultry. Note: These viruses have caused severe illness and death in people.
- Asian Lineage LPAI H7N9 viruses have been circulating among poultry without causing signs of illness in infected birds in China since 2013. These viruses also have caused human infections. In early 2017, Asian Lineage HPAI A(H7N9) virus infection of humans was reported in southern China, suggesting that some Asian Lineage LPAI H7N9 virus strains have evolved to become HPAI H7N9 viruses. These Asian Lineage HPAI H7N9 viruses could cause illness and death in infected poultry, and can cause severe illness and fatal outcomes in infected humans.
- To date, Asian lineage LPAI and HPAI H7N9 viruses reported in China have not been detected in poultry, wild birds, or humans in the United States.
Examples of Poultry Outbreaks of Avian Influenza in the United States
- Both HPAI and LPAI outbreaks occur among poultry from time to time in the United States. The United States Department of Agriculture (USDA) external icon is the lead federal agency for outbreak investigation and control in domestic birds.
- CDC coordinates with USDA and state health departments on appropriate public health measures and works with animal health colleagues to minimize public health risk posed by avian influenza A viruses.
H5 viruses (HPAI):
- Between 1997 and 2014, based on the World Organisation for Animal Health (OIE) external icon reporting criteria for avian influenza in commercial poultry, the United States experienced one outbreak of HPAI H5N2 virus in Texas in 2004 that was restricted to one poultry farm.
- The February 2004 Texas outbreak of HPAI H5N2 virus was reported in a flock of 7,000 chickens in south-central Texas. At that time, this was the first outbreak of HPAI in the United States in 20 years.
H7 viruses (HPAI and LPAI):
- In January 2016, an outbreak of North American lineage HPAI H7N8 virus was detected in a commercial poultry flock in Dubois County, Indiana, and subsequently North American lineage LPAI H7N8 was detected in eight nearby turkey flocks. Additional information is available from the USDA APHIS Confirmed Avian Influenza Detections -2016 external icon .
- In March 2017, an outbreak of HPAI H7N9 virus of North American wild bird origin was detected in two commercial chicken breeder flocks in Tennessee. Note: this North American lineage HPAI H7N9 virus is genetically unrelated to the Asian lineage HPAI H7N9 viruses reported in China, and is not believed to post the same risk to public health.
- No human infections with HPAI H7N8 or H7N9 viruses have been identified in the United States to date.
- The Department of Agriculture (USDA external icon ) is the lead federal agency for outbreak and investigation control in domestic birds in the United States. For more information: USDA ARS external icon and APHIS external icon web sites.
Avian Influenza A Virus Infection of Humans
Avian influenza A viruses do not normally infect people, but sporadic infections in people have occurred with some avian influenza A viruses. Illnesses in humans from avian influenza A virus infections have ranged in severity from asymptomatic to mild to severe and fatal disease. Human infections with avian influenza A viruses have most often occurred after contact with infected birds or their secretions or excretions. Three subtypes of avian influenza A viruses are known to infect people (H5, H7 and H9 viruses). Among these, Asian lineage H5N1 and H7N9 have caused the majority of infections in people.
Examples of Human Infections with Avian Influenza A viruses
Bird flu found in migratory birds in Himachal, cases in 4 other states — all you need to know
Representational Image of a poultry farm | Wikipedia Commons
New Delhi: Himachal Pradesh became the fifth Indian state — after Rajasthan, Madhya Pradesh, Haryana and Kerala — to confirm cases of avian flu after 1,800 migratory birds were found dead in the state’s Pong Dam Lake in the Kangra district.
“Slaughtering, sale, purchase and export of any poultry, birds, fish of any breed and their related products, including eggs, meat, chicken” has been prohibited in the district’s subdivisions of Fatehpur, Dehra, Jawali and Indora. Shops selling these products in the four subdivisions will also remain closed.
Principal Chief Conservator of Forests (Wildlife) Archana Sharma said, “The laboratory at the Indian Veterinary Research Institute (IVRI) in Bareilly had detected avian influenza in the samples of dead birds, according to information conveyed to us by the Centre Monday. We were awaiting confirmation by NIHSAD as it is the nodal body for detecting this disease.”
“The dead birds are being disposed off as per bird-flu protocol, adding that no such deaths have been reported so far from other water bodies in the state,” Hindustan Times quoted officials as saying. A rapid response team has been formed to deal with the outbreak, according to the director of animal husbandry, Dr Ajmer Dogra.
As of 4 January, Rajasthan has reported 425 bird deaths, all of which were traced back to the Jhalawar district, according to the state’s animal husbandry department. Meanwhile, Kerala has ordered the culling of nearly 40,000 birds within a one kilometer radius of the infected areas of Kottayam — which has seen 1,500 bird deaths — and Alappuzha districts. Last week, the bird flu virus was detected in 50 crows carcasses in Indore as well. In Haryana’s Barwala, around one lakh poultry birds reportedly died of the flu.
Alongside the Covid-19 outbreak this year, there have been bird flu outbreaks in Egypt, the United Kingdom (UK), South Korea, Japan and Vietnam.
What is bird flu
First discovered in China in 1997, bird flu, also known as avian flu, “is a highly infectious and severe respiratory disease in birds caused by the H5N1 influenza virus, which can occasionally infect humans as well, although human-to-human transmission is unusual” and does not happen easily.
People can get infected by the naturally occurring virus in birds only upon close interaction with “infected live or dead birds, or H5N1-contaminated environments” through touching infected birds, their droppings, bedding or killing and preparing infected poultry for cooking.
Markets where live birds are sold can also be another source, the UK’s National Health Services notes. If infected, the mortality rate in humans stands at 60 per cent, according to the World Health Organization (WHO).
Consumption of poultry products and other wild game is safe as long as it is cooked thoroughly. “Normal temperatures used for cooking (so that food reaches 70°C in all parts) will kill the virus,” the WHO notes. Majority of human infections can be traced back to slaughtering and handling of infected birds at home.
Besides its high mortality rate, if the H1N5 virus were to change genetically — something that occurs often in influenza viruses — such that it becomes more contagious and retains its “capacity to cause severe disease, the consequences for public health could be very serious.”
Symptoms, treatment, vaccine
Bird flu symptoms in humans include “fever, malaise, cough, sore throat, and muscle aches” as well as other early symptoms including abdominal pain, chest pain and diarrhoea. If the infection progresses quickly, severe respiratory illnesses and neurological changes can also occur.
If infected, humans tend to fall severely ill and require hospitalisation where oseltamivir — an antiviral medicine — is used widely to prevent severity of the disease and death.
Multiple vaccines have been developed for the H5N1 influenza virus and have been stockpiled in case of an emergency. Many other vaccine candidates are under development as well, in case the virus mutates and creates a pandemic. Several countries have been vaccinating the birds against the disease.
To prevent bird flu, one must wash hands with warm water and soap “especially before and after handling food, in particular raw poultry,” avoid contact with live birds and poultry, and use different utensils for cooked and raw meat.
The first outbreak of H5N1 in India was recorded 15 years ago in February 2006 at a poultry industry in the Maharashtra’s Nandurbar district. There was a major outbreak in West Bengal in 2008 and another one in Kerala in 2014.
Globally, 862 cases of bird flu have been recorded from 17 countries between January 2003 and December 2020, of which 455 were fatal, according to the WHO.
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Outbreaks of Avian Influenza A (H5N1) in Asia and Interim Recommendations for Evaluation and Reporting of Suspected Cases --- United States, 2004
During December 2003--February 2004, outbreaks of highly pathogenic avian influenza A (H5N1) among poultry were reported in Cambodia, China, Indonesia, Japan, Laos, South Korea, Thailand, and Vietnam. As of February 9, 2004, a total of 23 cases of laboratory-confirmed influenza A (H5N1) virus infections in humans, resulting in 18 deaths, had been reported in Thailand and Vietnam. In addition, approximately 100 suspected cases in humans are under investigation by national health authorities in Thailand and Vietnam. CDC, the World Health Organization (WHO), and national health authorities in Asian countries are working to assess and monitor the situation, provide epidemiologic and laboratory support, and assist with control efforts. This report summarizes information about the human infections and avian outbreaks in Asia and provides recommendations to guide influenza A (H5N1) surveillance, diagnosis, and testing in the United States.
On December 12, 2003, an outbreak of avian influenza A (H5N1) among poultry in South Korea was reported. Subsequent influenza A (H5N1) outbreaks among poultry were confirmed in Vietnam (January 8, 2004), on a single farm in Japan (January 12), in Thailand (January 23), in Cambodia (January 24), in China (January 27), in Laos (January 27), and in Indonesia (February 2). On January 19, a single peregrine falcon found dead in Hong Kong also tested positive for influenza A (H5N1) virus, but no poultry outbreak has been identified.
In Vietnam, as of February 9, a total of 18 human influenza A (H5N1) infections had been reported, resulting in 13 deaths. Patients ranged in age from 4 to 30 years 10 patients were aged <18 years. The cases included fatal infections in two sisters who were part of a cluster of four cases of severe respiratory illness in a single family.
In Thailand, influenza A (H5N1) infection was confirmed in four males, aged 6--7 years, and one female, aged 58 years. All five patients died ( 1 ). Other cases are under investigation.
Analysis of Viruses
Antigenic analysis and genetic sequencing distinguish between influenza viruses that usually circulate among birds and those that usually circulate among humans. Sequencing of the H5N1 viruses obtained from five persons in Vietnam and Thailand, including one sister from the cluster in Vietnam, has indicated that all of the genes of these viruses are of avian origin. No evidence of genetic reassortment between avian and human influenza viruses has been identified. If reassortment occurs, the likelihood that the H5N1 virus can be transmitted more readily from person to person will increase. Although all the genes are of avian origin, the current H5N1 viruses are antigenically distinguishable from those isolated from humans in Hong Kong in 1997 and 2003.
Genetic sequencing of the five human H5N1 isolates from Thailand and Vietnam also indicates that the viruses have genetic characteristics associated with resistance to the influenza antiviral drugs amantadine and rimantadine. Antiviral susceptibility testing confirms this finding. Testing for susceptibility of the H5N1 isolates to the neuraminidase inhibitor oseltamivir has demonstrated the sensitivity of these viruses to the drug testing to determine susceptibility to the neuraminidase inhibitor zanamavir is under way.
Interim Recommendations for U.S. Surveillance and Diagnostic Evaluation
CDC recommends that state and local health departments, hospitals, and clinicians enhance their efforts to identify patients who could be infected by influenza A (H5N1) virus and take infection-control precautions when influenza A (H5N1) is suspected (Box. Testing of hospitalized patients for influenza A (H5N1) infection is indicated when both of the following exist: 1) radiographically confirmed pneumonia, acute respiratory distress syndrome (ARDS), or other severe respiratory illness for which an alternative diagnosis has not been established and 2) a history of travel within 10 days of symptom onset to a country with documented H5N1 avian influenza infections in poultry or humans. Ongoing listings of countries affected by avian influenza are available from the World Organization for Animal Health*.
Testing for influenza A (H5N1) also should be considered on a case-by-case basis in consultation with state and local health departments for hospitalized or ambulatory patients with all of the following: 1) documented temperature of >100.4°F (>38°C) 2) cough, sore throat, or shortness of breath and 3) history of contact with poultry or domestic birds (e.g., visited a poultry farm, a household raising poultry, or a bird market) or a known or suspected patient with influenza A (H5N1) in an H5N1-affected country within 10 days of symptom onset.
Recommended Laboratory Testing Procedures
The highly pathogenic avian influenza A (H5N1) virus requires Biosafety Level (BSL)-3+ laboratory conditions for certain procedures. CDC recommends that virus isolation studies on respiratory specimens from patients who meet the testing criteria should not be performed unless all BSL-3+ conditions are met. However, clinical specimens can be tested by polymerase chain reaction (PCR) assays by using standard BSL-2 work practices in a Class II biological safety cabinet. CDC has developed real-time PCR protocols for various respiratory pathogens, including SARS and influenza A and B viruses. In addition, commercially available antigen-detection tests can be used under BSL-2 levels to test for influenza. Although these rapid tests for human influenza also can detect avian influenza A (H5N1) viruses, the sensitivity of these tests is substantially lower than that of virus culture or PCR ( 2 ).
Specimens from persons meeting clinical and epidemiologic indications for testing should be sent to CDC if they test positive for influenza A either by PCR or antigen detection testing, or if PCR assays for influenza are not available locally. CDC also will accept, for follow-up testing, specimens from persons meeting the clinical and epidemiologic indications but testing negative on the rapid tests when PCR assay was not available. Requests for testing by CDC should come through local and state health departments, which should contact CDC's Emergency Operations Center, telephone 770-488-7100.
Reported by: CDC/WHO Avian Influenza Response Team.
Since 1997, human infection with avian influenza viruses has been confirmed on five occasions § . The ability of avian viruses to transmit from person to person appears limited. Rare person-to-person infection was noted in the A (H5N1) outbreak in Hong Kong in 1997 ( 3,4 ) and in the A (H7N7) outbreak in the Netherlands in 2003 ( 5 ), but these secondary cases did not result in sustained chains of transmission or communitywide outbreaks. These previous experiences with avian influenza viruses suggest that limited person-to-person transmission of the current H5N1 viruses could occur.
The majority of the human H5N1 cases are apparently associated with direct exposure to infected birds or to surfaces contaminated with excretions from infected birds. The family respiratory illness cluster in Vietnam suggests the possibility of limited person-to-person transmission. However, other possibilities (e.g., transmission through exposure to surfaces contaminated by H5N1-infected poultry feces) cannot be ruled out. Although no evidence for sustained person-to-person transmission of influenza A (H5N1) has been identified, influenza viruses have the capacity to change quickly. Continued monitoring for new transmission patterns is an important aspect of the current investigation.
In 1997, the influenza A (H5N1) outbreak among persons in Hong Kong ended abruptly after the culling of poultry. However, the current outbreaks present challenges because of the large geographic areas and numbers of affected poultry. Asian poultry populations are maintained both on large commercial farms and in backyard flocks. In addition, infections among wild bird populations might be extensive, and the resources to address this problem are limited in certain affected countries. Because of increasing evidence that avian influenza viruses infect humans, persons involved in the slaughter of poultry potentially infected with avian influenza viruses or their contaminated environments should follow WHO recommendations for worker protection ¶ .
Because the influenza A (H5N1) virus could develop the ability to maintain sustained person-to-person transmission, WHO collaborating centers are working to coordinate vaccine development. Efforts are under way in the United Kingdom and the United States to develop influenza A (H5N1) reference viruses for use in vaccine preparation. The minimum estimated time necessary to complete reference virus development and safety testing is 3 months. Production by vaccine manufacturers of pilot lots of vaccine for clinical testing can begin only after reference virus development and safety testing have been completed. Decisions on whether to proceed with vaccine manufacture will depend, in part, on the evolution of the current outbreaks.
On February 4, CDC issued an order for an immediate ban** on the import of all birds from Cambodia, China (including Hong Kong), Indonesia, Japan, Laos, South Korea, Thailand, and Vietnam. Birds from these affected countries potentially can infect humans with influenza A (H5N1). This order complements a similar action taken by the U.S. Department of Agriculture (USDA).
CDC advises that travelers to countries in Asia with documented H5N1 outbreaks should avoid poultry farms, contact with animals in live food markets, and any surfaces that appear to be contaminated with feces from poultry or other animals. More information on travel is available from CDC at http://www.cdc.gov/travel. Additional information on influenza viruses and avian influenza is available from CDC at http://www.cdc.gov/flu. Updated information on human infections is available from WHO at http://www.who.int/en.
- CDC. Cases of influenza A (H5N1) --- Thailand, 2004. MMWR 2004 53:100--3.
- CDC. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 2003 52(No. RR-8).
- Bridges CB, Lim W, Hu-Primmer J, et al. Risk of influenza A (H5N1) infection among poultry workers, Hong Kong, 1997--1998. J Infect Dis 2002185:1005--10.
- Bridges CB, Katz JM, Seto WH, et al. Risk of influenza A (H5N1) infection among health care workers exposed to patients with influenza A (H5N1), Hong Kong. J Infect Dis 2000181:344--8.
- de Jong JC, Rimmelzwaan GF, Bartelds AI, Wilbrink B, Fouchier RA, Osterhaus AD. The 2002/2003 influenza season in the Netherlands and the vaccine composition for the 2003/2004 season [Dutch]. Ned Tijdschr Geneeskd 2003147:1971--5.
These protocols are available to public health laboratories and have been posted, under SARS (password required), by the Association of Public Health Laboratories at http://www.aphl.org/members_only/index.cfm.
§ Influenza A (H5N1) in Hong Kong in 1997 and 2003, influenza A (H9N2) in Hong Kong in 1999 and 2003, and influenza A (H7N7) in the Netherlands in 2003.
Russia Detects First Case Of H5N8 Avian Flu In Humans
Russia said Saturday that its scientists had detected the world's first case of transmission of the H5N8 strain of avian flu from birds to humans and had alerted the World Health Organization.
In televised remarks, the head of Russia's health watchdog Rospotrebnadzor, Anna Popova, said scientists at the Vektor laboratory had isolated the strain's genetic material from seven workers at a poultry farm in southern Russia, where an outbreak was recorded among the birds in December.
The workers did not suffer any serious health consequences, she added. They are believed to have caught the virus from poultry on the farm.
"Information about the world's first case of transmission of the avian flu (H5N8) to humans has already been sent to the World Health Organization," Popova said.
There are different subtypes of avian influenza viruses.
While the highly contagious strain H5N8 is lethal for birds, it had never before been reported to have spread to humans.
Popova praised "the important scientific discovery", saying "time will tell" if the virus can further mutate.
"The discovery of these mutations when the virus has not still acquired an ability to transmit from human to human gives us all, the entire world, time to prepare for possible mutations and react in an adequate and timely fashion," Popova said.
The WHO confirmed on Saturday that it had been notified by Russia about the development.
"We are in discussion with national authorities to gather more information and assess the public health impact of this event," a spokesperson said.
"If confirmed, this would be the first time H5N8 infects people."
WHO stressed that the Russian workers were "asymptomatic" and no onward human-to-human transmission had been reported.
People can get infected with avian and swine influenza viruses, such as bird flu subtypes A(H5N1) and A(H7N9) and swine flu subtypes such as A(H1N1).
According to the WHO, people usually get infected through direct contact with animals or contaminated environments, and there is no sustained transmission among humans.
H5N8 is lethal for birds, but it had never before been reported to have spread to humans Photo: dpa / Karl-Josef Hildenbrand
H5N1 in people can cause severe illness and has a 60 percent mortality rate.
Gwenael Vourc'h, head of research at France's National Institute for Agriculture, Food, and Environment, said that influenza viruses are known to evolve "quite quickly" and that there might have been other cases besides those reported in Russia.
"This is probably the tip of the iceberg," she told AFP.
Francois Renaud, a researcher at the French National Centre for Scientific Research (CNRS), said however that he was "not particularly worried" at this stage.
He added that the coronavirus pandemic had taught countries to react quickly to potential health threats. "Draconian measures will be taken to immediately stop the outbreak," he said.
Avian flu has raged in several European countries including France, where hundreds of thousands of birds have been culled to stop the infection.
Russia's Vektor State Virology and Biotechnology Center, which detected the transmission to the poultry farm workers, also developed one of the country's several coronavirus vaccines.
In the Soviet era the lab, located in Koltsovo outside the Siberian city of Novosibirsk, conducted secret biological weapons research.
It still stockpiles viruses ranging from Ebola to smallpox.
In televised remarks, Vektor chief Rinat Maksyutov said the lab was ready to begin developing test kits that would help detect potential cases of H5N8 in humans and to begin work on a vaccine.
The Soviet Union was a scientific powerhouse and Russia has sought to reclaim a leadership role in vaccine research under President Vladimir Putin.
Russia registered coronavirus vaccine Sputnik V in August, months before Western competitors and even before large-scale clinical trials.
After initial scepticism in the West, the Lancet journal this month published results showing the Russian vaccine -- named after the Soviet-era satellite -- to be safe and effective.
Human infection with avian influenza A (H5N8) – the Russian Federation
On 18 February 2021, the National IHR Focal Point for the Russian Federation notified WHO of detection of avian influenza A(H5N8) in seven human clinical specimens. These are the first reported detection of avian influenza A(H5N8) in humans. Positive clinical specimens were collected from poultry farm workers who participated in a response operation to contain an avian influenza A(H5N8) outbreak detected in a poultry farm in Astrakhan Oblast in the Russian Federation. The laboratory confirmation of the seven specimens were performed by the State Research Centre for Virology and Biotechnology VECTOR (WHO H5 Reference Laboratory). The age of seven positive cases ranged between 29 to 60 years and five were female.
Between 3 and 11 December, a total of 101 000 of 900 000 egg laying hens on the farm died. This high mortality rate prompted an investigation. Samples were collected from these birds and an initial detection of avian influenza A(H5N8) was performed by the Russian regional veterinary laboratory. On 11 December, the outbreak was confirmed by the World Organisation for Animal Health (OIE) Reference laboratory, and the Federal Centre for Animal Health (FGBI-ARRIAH), in Vladimir, the Russian Federation. Outbreak containment operations started immediately and continued for several days due to the large size of the poultry farm.
In addition to operations on the farm, acute and convalescent sera was collected from the seven positive human cases for serological testing. The results were suggestive of recent infection.
The cases remained asymptomatic for the whole follow-up duration (several weeks). Follow-up nasopharyngeal swabs were collected during medical observation period and were tested negative for avian influenza A(H5N8). No obvious clinical manifestations were reported from any farm workers under medical surveillance, their family members, or other close contacts of the seven cases.
Influenza A(H5N8) viruses isolated from this poultry outbreak in Astrakhan belonged to clade 184.108.40.206b of avian influenza A(H5Nx) viruses. In 2020, avian influenza A (H5N8) viruses were also detected in poultry or wild birds in Bulgaria, the Czech Republic, Egypt, Germany, Hungary, Iraq, Japan, Kazakhstan, the Netherlands, Poland, Romania, the United Kingdom, and the Russian Federation.
Public health response
On receiving the initial signal of a probable outbreak of highly pathogenic avian influenza (HPAI) at the poultry farm on 3 December 2020, the national authorities took immediate measures including cessation of poultry production cycles, and product transportation from the affected farm.
Between 11 and 18 December, several measures including culling and disposing of poultry, eggs, litter and disinfection of contaminated premises were taken as part of outbreak response activities
During and after the culling of all the poultry, nasopharyngeal swabs and serum samples were collected from poultry farm workers and personnel involved in outbreak response at the farm. The surveillance activities, both within and outside of the containment area, was intensified. A total of 24 close contacts of the confirmed cases have been identified and traced. In total, 150 individuals were monitored for clinical indication of respiratory disease and received antiviral prophylaxis therapy. No symptoms were reported among these individuals.
Whole Genome Sequencing of avian influenza A (H5N8) viruses isolated from poultry and from one of the seven human cases was performed and were uploaded to the Global Initiative on Sharing All Influenza Data (GISAID) database on 20 February 2021. Genetic and phenotypic characterization of the virus is ongoing.
WHO is following up with the public health authorities in the Russian Federation, including implementation of public health measures warranted by such events, and with the WHO Global Influenza Surveillance and Response System (GISRS) on further analysis and assessment of the virus materials and serum samples. On 20 February, a special briefing by the head of the Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing was organized for the state Russian media to inform the public about these cases and the implications.
WHO risk assessment
Since 2004, avian influenza A(H5) viruses have spread from Asia to Europe via wild birds. The genetic clade 220.127.116.11 H5 viruses have often reassorted among other avian influenza viruses, resulting in avian influenza A(H5N1), A(H5N2), A(H5N3), A(H5N5), A(H5N6) and A(H5N8) viruses, some of which have been detected in birds in many countries .
In the Russian Federation, avian influenza A(H5N8) of clade 18.104.22.168 was isolated for the first time in 2014 in a wild bird in the northern region of Russian Far East.
As mentioned earlier, all the seven cases with PCR-positive results were clinically asymptomatic. All close contacts of these cases were clinically monitored, and no one showed signs of clinical illness. Infections with avian influenza viruses of the same clade (H5 clade 22.214.171.124) have been reported from China since 2014 in people with exposure to infected birds. The likelihood of human infections with influenza A(H5N8) viruses has been considered to be low.
Further genetic and antigenic characterization and information on seroconversion among contacts of the positive cases is required to fully assess the risk.
The development of zoonotic influenza candidate vaccine viruses for potential use in human vaccines, coordinated by WHO, remains an essential component of the overall global strategy for influenza pandemic preparedness.
Based on currently available information, the risk of human-to-human transmission remains low.
These cases do not change the current WHO recommendations on public health measures and surveillance of animal and seasonal human influenza, which should continue to be implemented. Respiratory transmission occurs mainly by droplets, disseminated by unprotected coughs and sneezes. Short-distance airborne transmission of influenza viruses may occur, particularly in crowded enclosed spaces. Hand contamination, direct inoculation of virus, exposure to infected birds or virus-contaminated materials or environments are potential sources of infection.
When avian influenza viruses are circulating in an area, the people involved in specific, high-risk tasks such as sampling sick birds, culling and disposing of infected birds, eggs, litter and cleaning of contaminated premises should be trained on how to protect themselves, and on proper use of personal protective equipment (PPE) . People involved in these tasks should be registered and monitored closely by local health authorities for seven days following the last day of contact with poultry or their environments.
Due to the constantly evolving nature of influenza viruses, WHO continues to stress the importance of global surveillance to detect virological, epidemiological and clinical changes associated with circulating influenza viruses that may affect human (or animal) health and timely virus sharing for risk assessment.
Thorough investigation of all potential novel influenza human infections is warranted. All human infections caused by a novel influenza subtype are notifiable under the International Health Regulations (IHR), and State Parties to the IHR are required to immediately notify WHO of any laboratory-confirmed case of a recent human infection caused by new influenza A subtype with the potential to cause a pandemic (please see case definitions for diseases requiring notification under the IHR ). Evidence of illness is not required.
In the case of a confirmed or suspected human infection, a thorough epidemiologic investigation of history of exposure to animals, of travel, and contact tracing should be conducted, even while awaiting the confirmatory laboratory results. The epidemiologic investigation should include early identification of unusual respiratory events that could signal person-to-person transmission of the novel virus. Clinical samples collected from the time and place that the case occurred should be tested and sent to a WHO Collaboration Center for further characterization.
Travelers to countries with known outbreaks of avian influenza should avoid farms, contact with animals in live animal markets, entering areas where animals may be slaughtered, or contact with any surfaces that appear to be contaminated with animal feces. Travelers should also wash their hands often with soap and water. Travelers should follow good food safety and good food hygiene practices.
Based on the currently available information, WHO advises against any special traveler screening at points of entry or restrictions on travel and/or trade with the Russian Federation.
Avian Influenza: Poultry keepers advised to remain vigilant as heightened biosecurity measures lifted
The Chief Veterinary Officers from England, Scotland and Wales are advising poultry keepers to remain vigilant as the Avian Influenza Prevention Zone (AIPZ) is due to be lifted from midday tomorrow (Saturday 15 May).
These additional biosecurity measures, which were introduced across Great Britain in November 2020, have been vital in protecting flocks across the country from the disease which is circulating in wild birds.
Defra, the Scottish Government and the Welsh Government have been working closely with industry and bird keepers to ensure that there are strict biosecurity measures in and around poultry premises to help keep flocks safe.
The risk of bird flu in poultry with good biosecurity has now been reduced to ‘low’ for all poultry. As a result, the mandatory enhanced biosecurity requirements that were brought in as part of the AIPZ on 11 November and the additional biosecurity measures introduced on 31 March will be lifted from midday on Saturday 15 May.
In a joint statement, Great Britain’s three Chief Veterinary Officers said:
This will be welcome news for bird keepers across the country who have put great effort into keeping their flocks safe this winter.
We have taken swift action to contain and eliminate this disease, and we urge all bird keepers – whether they have just a few birds or thousands – to continue to do their bit to maintain strict biosecurity measures on their premises, so that we do not lose the progress that we have made over the past few months. Low risk does not mean no risk.
All poultry and bird gatherings, including pigeon gatherings organised for races from mainland Europe, will also be permitted, provided organisers notify the Animal and Plant Health Agency at least seven days before the event takes place and that they comply with the provisions of the new General Licence.
Public health advice is that the risk to human health from the H5N8 virus strain is low and from the H5N2, H5N5 and H5N1 virus strains is very low. Food standards bodies also advise that avian influenza poses a very low food safety risk for UK consumers and does not affect the consumption of poultry products, including eggs.
Poultry and captive bird keepers are advised to remain vigilant for any signs of disease in their birds and any wild birds, and seek prompt advice from their vet if they have any concerns. They can help prevent avian flu by maintaining good biosecurity on their premises, including:
- Fencing off ponds, streams, boggy areas or standing water and draining them where possible
- Netting or covering ponds
- Removing any wild bird feed sources
- Deterring wild birds by regularly walking through the area or by using predator decoys
- Cleansing and disinfecting concrete or other permeable areas
- Putting down wood shavings in wet areas
- Limiting the number of people who come onto the site
- Using disinfectant foot dips when entering and exiting enclosures or houses
Poultry and captive bird keepers and members of the public should continue to report dead wild birds to the Defra helpline on 03459 33 55 77 (option 7), and keepers should report suspicion of disease to APHA in England on 03000 200 301, Wales on 0300 3038268 and in Scotland through the Local Field Service Office.
Poultry keepers should familiarise themselves with our avian flu advice.
- Avian influenza is in no way connected to the COVID-19 pandemic, which is caused by the SARS-CoV-2 virus and is not carried in poultry.
- The government’s outbreak assessment following recent cases in England can be accessed here.
- For more advice and regular updates on the latest situation, visit Governments’ avian flu pages: in England, Scotland, Wales and NI.
- Food safety advice for cooking poultry and eggs remains unchanged. See NHS advice on safe cooking of eggs and poultry.
We publish a report (updated regularly) on findings of highly pathogenic avian influenza (bird flu) in wild birds in Great Britain available here, and further information on avian influenza findings in wild birds in GB and Europe can be found in our outbreak assessments.
The measures followed a number of confirmed cases of avian influenza in England. This includes:
- H5N2 (low pathogenic) avian influenza confirmed at a site near Deal in Kent on 2 November.
- H5N8 (highly pathogenic) avian influenza confirmed at a site near Frodsham in Cheshire on 2 November
- H5N8 (highly pathogenic) avian influenza confirmed at a broiler breeder farm near Leominster in Herefordshire on 10 November .
- H5N8 (highly pathogenic) avian influenza was confirmed at a site near Stroud in Gloucestershire on 19 November.
- H5N8 (highly pathogenic) confirmed at a premises near Melton Mowbray in Leicestershire on 21 November.
- H5N8 (highly pathogenic) influenza confirmed at two premises near Northallerton, North Yorkshire on 29 November and 1 December.
- H5N8 (highly pathogenic) influenza confirmed at a premises near Attleborough, Breckland, Norfolk on 4 December.
- H5N8 (highly pathogenic) avian influenza confirmed at a premises near King’s Lynn, King’s Lynn and West Norfolk, Norfolk on 5 December.
- H5N8 (highly pathogenic) avian influenza confirmed at a wild bird rescue centre near Droitwich Spa, Wychavon, Worcestershire on 13 December.
- H5N8 (highly pathogenic) avian influenza confirmed at a premises near Near Willington, South Derbyshire, Derbyshire on 15 December.
- H5N1 (highly pathogenic) avian influenza confirmed in backyard chickens near Hawes, Richmondshire, North Yorkshire on 18 December.
- H5N8 (highly pathogenic) avian influenza confirmed in breeding ducks at a premises near Attleborough, Norfolk on 19 December.
- H5N8 (highly pathogenic) avian influenza confirmed in a backyard flock near Gillingham, Dorset on 19 December.
- H5N8 (highly pathogenic) avian influenza confirmed in captive birds near Attleborough, Norfolk on 26 December.
- H5N8 (highly pathogenic) avian influenza confirmed in rearing ducks at a premises near Watton, Norfolk on 28 December.
- H5N8 (highly pathogenic) avian influenza confirmed in backyard poultry at a premises near Exmouth, West Devon, Devon on 29 December.
- H5N8 (highly pathogenic) avian influenza confirmed in laying chickens at a premises near Redcar, Redcar & Cleveland on 6 February 2021.
- H5N3 avian influenza (low pathogenic) confirmed in turkeys at premises near Winsford, Cheshire West and Cheshire on 26 March.
- H5N8 (highly pathogenic) avian influenza confirmed at a commercial broiler farm near Uttoxeter, East Staffordshire, on 27 March 2021.
- H5N8 (highly pathogenic) avian influenza confirmed in captive birds near Skelmersdale, West Lancashire, on 31 March 2021
In each case Defra has acted quickly to cull affected birds and to introduce movement restrictions to limit the risk of the disease spreading.
If you&rsquore a clinician, laboratorian or public health worker
Avian influenza refers to disease caused by infection with avian (bird) influenza (flu) Type A viruses. Avian influenza A viruses can infect the respiratory and gastrointestinal tract of birds and have been isolated from more than 100 different species of wild birds around the world. Aquatic birds including gulls, terns, and shorebirds, and waterfowl such as ducks, geese and swans are considered reservoirs (hosts) for avian influenza A viruses. Some avian influenza A viruses can infect domestic poultry, and outbreaks of avian influenza in domestic poultry occur worldwide. For more information: World Organisation for Animal Health (OIE) Avian Influenza Portal external icon and the World Animal Health Information Database external icon . Some avian influenza A viruses have infected other animal species, and sporadic human infections with some avian influenza A viruses have occurred.
Classification of Avian Influenza A Viruses
Avian influenza A viruses are classified into two categories: low pathogenic avian influenza (LPAI) and highly pathogenic avian influenza (HPAI) based on their molecular characteristics and their ability to cause disease and mortality in chickens in a laboratory setting. For more information: OIE Terrestrial Animal Health Code, Infection with Avian Influenza Viruses external icon .
Both HPAI and LPAI viruses can spread rapidly in wild birds and poultry. Most avian influenza A viruses circulating among wild birds and poultry are classified as LPAI A viruses and typically cause asymptomatic infection to mild illness. HPAI viruses can cause severe disease and high mortality in infected wild birds and poultry. Whether a virus is classified as a LPAI or HPAI virus applies to the ability to cause disease in infected poultry, and does not refer to whether it causes disease in humans. Both LPAI and HPAI virus infections of humans have resulted in a wide spectrum of illness, from mild to severe and fatal.
Examples of Avian Influenza A Virus Infections in Wild Birds in the U.S.
Background: Outbreaks of avian influenza among poultry occur periodically worldwide. For more information: World Organization for Animal Health (OIE&rsquos) World Animal Health Information Database (WAHID) external icon , OIE&rsquos WAHID Handistatus II external icon , the U.S. Department of Agriculture&rsquos (USDA&rsquos) Avian Influenza Outbreaks in the United States Q&A pdf icon [160 KB, 3 pages] external icon , and CDC&rsquos Outbreaks of Avian Influenza in North America. CDC coordinates with, the World Health Organization and other international partners to minimize the public health risk posed by avian influenza A viruses.
Examples of Poultry Outbreaks of Avian Influenza Worldwide:
H5 viruses (HPAI):