Avian Flu in Britain
How One Nation Handles Biosecurity for Chickens
by Susie Kearley
Outbreaks of Avian flu in Britain have been regular occurrences over the past 20 years. In fact, bird flu has been a big a problem in Europe, Asia, and Africa since the 1990s, with occasional outbreaks in parts of the USA and Australia too. The last outbreak in the USA was in 2017, in a poultry flock kept on commercial premises along the Mississippi Flyway. In 2014/15, 21 US states were affected when there were outbreaks along the migratory routes for birds along the Pacific, Central, and Mississippi flyways.
Avian flu in Britain is more commonplace however, and every time an outbreak is identified, restrictions are put in place across the country. The last outbreak was finally eradicated in February 2018, with restrictions lifted in May 2018, but British authorities still recommend good biosecurity measures to prevent another outbreak.
Every time an outbreak of avian flu in Britain is identified, a prevention zone is declared by the Department for Environment, Food & Rural Affairs. Domestic and farm birds in the area must be kept in sheds or enclosures until it’s deemed safe to let them out again. This is primarily to protect them from potential infection from wild birds. In January 2018, the prevention zone was extended from local areas affected by the disease, to cover the whole of England and Wales. It was eventually lifted four months later.
While prevention zones are in place, even free-range hen keepers have to pen their birds, and after 12 weeks the birds lose their free-range status, because under EU legislation, when a chicken has been inside for more than 12 weeks, it can no longer be called free-range. Most farmers affected label their eggs, explaining that the birds’ confinement is a temporary situation, for the birds’ own welfare. Once the threat of infection has passed, the prevention zone is lifted.
However, all bird keepers across the UK are asked to pay ongoing attention to their biosecurity, even when the risk of infection is considered low. Many keepers use shoe disinfectant mats before entering their bird pens or barns (this is a legal requirement when you’re inside an active prevention zone). Even wildlife reserves like the London Wetland Centre have disinfectant mats at every doorway, to disinfect visitors’ shoes as they go in and out of each area. This helps to prevent the spread of disease.
Avian flu in Britain was once a relatively rare occurrence. The earliest recorded incidents of bird flu were in 1878, but the numbers affected were relatively small. In those days, they called it “fowl plague.” There were 15 reports of Avian flu around the world between 1959 and 1995, but losses were small.
Outbreaks of the disease became more common around the world in the 1990s because of changes to agricultural practices. Intensive poultry production called for higher density flocks, and frequent movement of the flocks meant disease could spread easily by contact with diseased birds and contaminated equipment.
Avian flu reached epidemic proportions between 1996 and 2008, when there were 11 outbreaks over 13 years, resulting in the deaths of millions of birds. When a particularly nasty strain of bird flu, HPAI, first hit the headlines in 1996, small flocks were often implicated in the spread of disease, but subsequent research has shown that small flocks are much less of a threat than large commercial flocks, especially when the biosecurity of the larger flocks is poor.
The recent epidemic of avian flu in Britain began in December 2016 when localized restrictions on bird movements were put in place. Despite this, cases of a particularly nasty strain of bird flu peaked in early 2017, with 13 diseased flocks identified among British poultry and gamebirds (six were backyard flocks; seven were commercial). Forty-five wild birds with a different strain of avian flu were also identified, mostly among water birds. Some strains of bird flu are deadly, while others just affect egg production. Sometimes potentially infected flocks are culled to stop the disease from spreading.
Avian Influenza Prevention Zones
During outbreaks of avian flu in Britain, restrictions on movement of animals and strict biosecurity measures apply within prevention zones. The UK was officially declared free of bird flu in September 2017, but then an outbreak of avian flu in Britain occurred in Dorset in January 2018, and prevention zones were re-introduced. The situation has now improved and restrictions for poultry keepers across the UK were lifted in May 2018.
The UK’s Chief Veterinary Officer, Christine Middlemiss, said: “The Avian Influenza Prevention Zone was lifted across England due to the scientific and veterinary evidence showing that the risk of this disease has now returned to low. It is essential that all bird keepers continue to maintain good biosecurity measures to protect their birds and help prevent outbreaks or spread of diseases.”
The Department for Environment, Food & Rural Affairs advise taking the following precautions to prevent avian flu in Britain among poultry flocks:
- minimize movement in and out of your bird enclosure;
- clean footwear before and after visiting your birds;
- keep bird enclosures clean and tidy, regularly disinfecting hard surfaces;
- humanely control rodents;
- place birds’ food and water in fully-enclosed areas that wild birds cannot access. Remove spilled feed;
- keep your birds separate from wildlife by putting fencing around their outdoor areas;
- make sure equipment, feed and bedding are stored undercover so they cannot be contaminated by wild birds;
- keep chickens and turkeys separate from ducks and geese.
- Read more: www.gov.uk/guidance/avian-influenza-bird-flu
In the United States, the Center for Disease Control has also issued guidelines for the prevention of bird flu. They say, “As a general precaution, people should avoid wild birds and observe them only from a distance. Avoid contact with domestic birds (poultry) that appear ill or have died. Avoid contact with surfaces that appear to be contaminated with feces from wild or domestic birds.” Obviously you have to clean your coop, but do be wary of the low risk of infection from wild birds. Read their full guidelines here: www.cdc.gov/flu/avianflu/avian-flu-summary.htm
The US Department of Agriculture is the primary federal agency leading outbreak investigations and implementing controls among domestic flocks. Read about their work on bird flu here: www.usda.gov/topics/animals/one-health/avian-influenza
How Avian Influenza Spreads
Avian flu spreads through direct contact, saliva, feces, contaminated feed and water, contaminated equipment, or dirty vehicles, clothing or footwear. The virus mutates and new strains emerge regularly, so it’s a constant threat, but it’s not airborne.
It is possible for humans to contract the disease, but it’s unlikely unless the person has prolonged intensive contact with infected birds.
Recognizing Symptoms of Avian Flu
The most deadly strain of avian flu is HPAI. The clinical signs are: a swollen head, blue discoloration of the neck, loss of appetite, respiratory distress, diarrhea, reduced egg laying, and death. Low pathogenic avian influenza (LPAI) is not as serious. The symptoms are mild breathing problems, but it can be hard to spot. Read more about avian influenza symptoms. Also read up on sick chicken symptoms.
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