Avian flu: What are the symptoms and how common is the virus among humans?

Avian influenza has been detected in two British poultry workers as virus rages in Europe

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People have been warned to stay away from sick or dead birds washing on beaches across the UK as concerns over a bird flu outbreak grow.

In recent weeks, reports of bird carcasses washing up on shores in west and north Wales have increased as the disease continues to affect wild bird colonies around the UK.

The virus was also detected in two more British poultry workers in July, taking the total number of people taken ill with the virus this year to four as Europe continues to battle an ongoing outbreak.

Earlier this month, the European Food Safety Authority (EFSA) has meanwhile urged people to keep their cats and dogs inside after 24 felines tested positive for avian flu in Poland in the space of a month, which in some cases resulted in death.

The source of the contamination has not yet been determined.

The EFSA said in December that the epidemic was the “largest ever observed in Europe”.

In its first year, from October 2021 to September 2022, there were 2,520 outbreaks in poultry, 227 in captive birds and 3,867 detections in wild birds across 37 European countries.

The two cases the UK Health Security Agency reported in May were believed to be linked to exposure to sick birds on a single poultry farm, where both people concerned had recently worked.

Bird-to-human transmission is rare and has only occurred a small number of times in the UK, with the risk described as “low” – but here is everything you need to know, just to be on the safe side.

What is bird flu?

According to the NHS, avian influenza is an infectious type of flu that spreads among our feathered friends but only rarely infects humans.

There are multiple strains of bird flu and most do not infect people at all.

Strains that can infect humans do not do so easily, although cases and deaths linked to infection from bird flu have been known.

How does it spread to humans?

Avian influenza is spread to humans through close contact with an infected animal, dead or alive. It is passed through bodily fluids such as faeces, saliva and nasal droplets.

One of the British sufferers reported in May was diagnosed by nasal swap, suggesting they had contracted the virus by inhalation.

Touching an infected bird or coming into contact with its droppings or bedding, or preparing its meat for consumption, can cause a human to become infected.

According to the NHS, visiting places like livestock markets in areas where there has recently been an outbreak may put an individual at greater risk of catching bird flu.

However, you cannot get it from eating fully-cooked meat or eggs from an infected bird, according to the health service.

Can it be transmitted between humans and, if so, how?

While it is not easy for bird flu to pass from human to human, it has happened before.

Like normal flu, it is spread through close personal contact where the virus is present in droplets in the air.

Peter Horby, professor of emerging infectious diseases and director of the Pandemic Sciences Centre at the University of Oxford, told The Independent: “Most of the unusual avian or bird flu viruses that crossover are not very well adapted to humans so they tend to just cause the odd case now and again, with no onward transmission.

“So, in this case, you would want to closely monitor the close contacts of this person. But, the likelihood is, there’ll be no onward transmission. We have to watch these very carefully because sometimes you do get an animal virus that is well-adapted to humans or becomes adapted to humans and then it is a pandemic risk.”

What are the symptoms in people?

Symptoms of bird flu are similar to other types of flu. According to the NHS, they can include:

• High temperature or feeling hot or shivery
• Muscle aches
• A headache
• A cough

Symptoms may take between three to five days after infection to appear.

If you are at risk of having been affected, some early symptoms of infection may include:

• Diarrhoea and sickness
• Stomach ache
• Conjunctivitis
• Chest pain
• Bleeding nose and/or gums