A particular problem has been the H5N8 strain, which emerged in Russia a few months ago and since then has been causing havoc in poultry flocks all over Europe, the Middle East and India. In addition, other strains have been a problem in parts of east Asia, and countries in Africa have struggled to get rid of the H5N1 type of the disease.

Poultry farmers and backyard flock owners have been asked again and again to implement stronger biosecurity measures to protect birds, and help prevent any transfer of disease into humans. But what are the best measures poultry keepers can take to prevent outbreaks spreading?

1. Keep your birds indoors at high-risk times

Government vets in the UK, and similar regulators in other parts of Europe, have ordered poultry keepers to move their birds indoors for their own protection. These prevention measures aim to keep birds separate from migrating wild birds, which are thought to spread the virus. The UN's Food and Agriculture Organisation (FAO) said in November that all countries along the migration paths of waterbirds were at risk.

2. If they can't go indoors, prevent access by wild birds to their food

However, measures to separate poultry from wild birds must be balanced with welfare. Certain birds, such as geese or ostriches, cannot easily be kept indoors. UK advice suggests taking other measures to keep these birds separate from wild birds, like making sure their feed and water sources cannot be accessed by wild birds.

3. Cover your run

"Even when birds are housed, a risk of infection remains, so this must be coupled with good biosecurity," said UK Chief Veterinary Officer Nigel Gibbens when announcing the avian flu prevention measures that sent poultry indoors. Some housed birds may be able to have contact with wild birds, such as smallholding flocks in outdoor runs. The British Hen Welfare Trust recommends covering your run.

4. Make sure coops and other housing are kept clean

Another good move to help prevent further spread of the disease is to take extra steps to keep your coop clean, including disinfecting all bird houses on a regular basis. For commercial poultry owners, UK Government advice is to thoroughly clean and disinfect housing at the end of a production cycle.

5. Limit visitors to your flock

People moving between poultry flocks and the outside world could be a key factor in disease spread if infected wild birds are in the area. The UK government recommends reducing the movement of people, vehicles or equipment to and from areas where poultry are kept. US producers trying to limit the spread of disease in 2015's avian flu outbreaks found that keeping essential equipment sets inside the house reduced the number of necessary trips between buildings.

6. Disinfect visitors and vehicles

If you can't reduce the movement of people into your flock any further, you can still improve you biosecurity even more by taking precautions to avoid the transfer of contamination by cleansing and disinfection of equipment, vehicles and footwear. Author and backyard poultry keeper Christine Heinrichs recommends keeping a separate set of old clothes and shoes to visit your small flock. "Inexpensive disposable boot covers can allow neighbours to be welcome visitors without compromising flock security," she adds.

7. Report any suspicions straight away

The UK's Department of Environment, Food and Rural Affairs (Defra) provides this summary of symptoms of avian flu in poultry: "Clinical signs that poultry keepers should look for in their birds include a swollen head, discolouration of neck and throat, loss of appetite, respiratory distress, diarrhoea and fewer eggs laid – although these vary between species of bird."

Defra recommends contacting a vet straight away if you have any concerns - speedy action will help to protect other flocks in the area if the disease is confirmed.