Bird flu, or avian flu, is an infectious type of influenza that spreads among birds. In rare cases, it can affect humans.
There are many different strains of bird flu virus, most of which don’t infect humans. However, 4 particular strains have caused serious concern in recent years:
- H5N1 (since 1997)
- H7N9 (since 2013)
- H5N6 (since 2014)
- H5N8 (since 2016)
Although these viruses don’t infect people easily and aren’t usually transmitted from human to human, several people have been infected around the world, leading to a number of deaths.
Bird flu affects many species of birds, including chickens, ducks, turkeys and geese. It can be passed between commercial, wild and pet birds. Birds don’t always get sick from infection, so seemingly healthy birds may still pose a risk to people who come into contact with them.
Bird flu in the UK
No humans have been infected with H5N1, H7N9, H5N6 or H5N8 bird flu in the UK, although plans are in place to manage any suspected cases.
In January 2018, a number of cases of H5N6 bird flu were identified in wild birds in 2 separate locations in the UK (South Dorset and Warwickshire). This led to the Department for Environment, Food and Rural Affairs (Defra) introducing a Bird Flu Prevention Zone in England.
During 2016/17, there were several outbreaks of H5N8 bird flu in poultry flocks and wild birds in the UK and Europe. Since then, there have been further outbreaks of H5N8 across the Middle East, Africa and Asia. Worldwide, there have been no human cases of H5N8.
The last reported case of H5N1 in birds in the UK was in early 2008. H7N9 hasn’t been detected in wild birds or poultry in the UK.
Signs and symptoms
Like other types of flu, bird flu symptoms often include:
- a high temperature (fever)
- aching muscles
- respiratory symptoms, such as a cough or runny nose
These symptoms can come on suddenly. The time from infection to the start of symptoms (incubation period) is usually 3 to 5 days, although in some cases it can be up to 7 days.
Within days of symptoms appearing, potentially fatal complications such as pneumonia, acute respiratory distress syndrome and multiple organ failure may develop. Prompt treatment with antiviral medication may help prevent complications and reduce the risk of death.
Treatment for bird flu
People with suspected symptoms of bird flu will be advised to stay at home or be cared for in hospital in isolation from other patients.
In addition, other recommendations include:
- drinking plenty of fluids and eating healthily
- taking medication to help treat fever and pain, such as paracetamol and ibuprofen
In the UK, certain antiviral medications have been stockpiled for use in the event of a flu outbreak. These medications work by stopping the virus multiplying in your body.
Oseltamivir (Tamiflu) and zanamivir (Relenza) help reduce the severity of the condition, prevent complications and improve the chances of survival.
For regular flu, these medications are most effective if given within 48 hours of symptoms developing, but it’s not clear if this is the case for bird flu. They should be given as soon as possible to people suspected or proven to be infected, sometimes even if it’s more than 48 hours after symptoms started. This decision would be made by the doctor prescribing the medication.
These medications may also be given as a preventative measure to people who could have been exposed to bird flu viruses – for example, other household members, healthcare workers or people who’ve been in close contact with infected birds, depending on the circumstances.
Complications such as bacterial pneumonia may develop in some people and can be treated with regular antibiotics.
People who are severely affected may need to be given extra oxygen to help them breathe – for example, through a ventilator (a machine that assists with breathing).
When to seek medical advice
Contact your GP or call NHS 111 immediately if you experience symptoms and have visited an area affected by bird flu in the past 2 weeks.
An initial assessment can be made over the phone, at a GP surgery, at home or in a side room at a hospital.
Bird flu is diagnosed based on your symptoms and the likelihood that you’ve been exposed to an infected bird. You should tell the doctor if you have:
- recently travelled to an area affected by bird flu and if you’ve been close (within a metre) to live or dead domestic fowl or wild birds, including those at bird markets
- had close contact (touching or speaking distance) with anyone who has a severe respiratory illness
- had contact with anyone who died unexpectedly and was from an area that had an outbreak
If bird flu is suspected, the following tests will be carried out to establish the diagnosis:
If the laboratory tests and chest X-ray results are normal, it’s unlikely you have bird flu.
How bird flu spreads to humans
Bird flu is spread through direct contact with infected birds (dead or alive), an infected bird’s droppings, or secretions from their eyes or respiratory tract.
Close and prolonged contact with an infected bird is generally required for the infection to spread to humans. For example:
- touching infected birds that are dead or alive
- inhaling or being in contact with dried dust from the droppings or bedding of infected birds
- inhaling or being in contact with droplets sneezed by infected birds
- culling, slaughtering, butchering or preparing infected poultry for cooking
Another possible source of bird flu can be live markets, where birds are sold in crowded and sometimes unsanitary conditions. Avoid visiting these markets if you’re travelling in countries that have had an outbreak of bird flu.
Bird flu isn’t transmitted through cooked food, so cooked poultry and eggs are safe to eat in areas that have experienced outbreaks of bird flu.
Preventing bird flu
There are a number of things you can do to reduce your risk when visiting areas where outbreaks have been reported:
- avoid visiting live animal markets and poultry farms
- avoid contact with surfaces that are contaminated with bird droppings
- don’t pick up or touch birds (dead or alive)
- don’t eat or handle undercooked or raw poultry, egg or duck dishes
- don’t bring any live poultry products back to the UK, including feathers
- always practise good personal hygiene, such as washing your hands regularly
There are no restrictions on travel to countries that have been or are currently affected by bird flu.
Read more about preventing bird flu.
Reporting suspected cases of bird flu
Bird flu is a notifiable disease in animals, so you should report any suspected case in animals to the Animal and Plant Health Agency (APHA), even if you’re not sure.
Call the Department for Environment, Food and Rural Affairs (Defra) helpline on 03459 33 55 77 if you find 5 or more dead birds in the same place.
You can read more about notifiable diseases in animals and how to spot bird flu and what to do if you suspect it, on the GOV.UK website.
The World Health Organization (WHO) confirmed that by January 2018, 860 people had been infected with the H5N1 virus worldwide and 454 had died. Indonesia, Egypt and Vietnam experienced most cases and fatalities.
Reports of people being infected with the H7N9 virus across mainland China began in March 2013. By January 2018, there had been 1,565 confirmed cases and 612 deaths. Most cases were among middle-aged and elderly men. A small number of cases were reported in travellers from Hong Kong, Taiwan, Macao, Malaysia and Canada.
Since 2014, there have been 19 human cases of infection with H5N6, all reported in mainland China. This strain is different to the H5N6 seen in Europe – the latter hasn’t been associated with any human cases.
There have been some reports of limited human-to-human transmission of H5N1 and H7N9 viruses, usually as a result of very close contact between family members or in hospital settings. The H5N6 virus seen in China has so far not been transmitted from person to person.
People who’ve had bird flu generally developed the virus after coming into close and prolonged contact with infected birds. Millions of birds have been killed during outbreaks to prevent the disease spreading and being passed on to people.