'Mystery virus' that's been making everyone ill over Christmas has been explained

A health expert has revealed why this annoying 'mystery virus' has been making us all ill over Christmas.

If you've been able to avoid catching the dreaded bug during the festive period, you'll definitely know someone who's got it.

Whether it's friends, family members or people at work, it feels like everyone has been coughing, sneezing and dealing with a runny nose.

While feeling unwell is not the best way to start the New Year, the good news is that this mystery virus shouldn't keep you out for too long, although some symptoms can linger for up to two weeks.

Ian Budd, lead prescribing pharmacist at Chemist4U, has explained what is most likely going on.

Adenovirus is a highly contagious flu-like virus (Getty Stock Images)

"What we’re seeing in the news, often called a ‘mystery virus’ or a fast-spreading throat/respiratory bug, lines up with what clinicians and public health bodies are seeing: adenovirus, a group of common respiratory viruses that circulate widely," he said.

What is an adenovirus?

According to Public Health Scotland, adenoviruses 'can cause a wide range of illnesses such as common cold or flu-like symptoms'.

"Although human disease may often be mild or moderate, it can be severe especially when untreated in elderly or immunocompromised individuals," the health service notes.

While these viruses 'aren’t new', Budd says that 'more people are noticing symptoms and heading to their GP'.

What is the difference between an adenovirus and a cold or flu?

"Compared to a cold, adenovirus can be more likely to cause fever and conjunctivitis, and symptoms can last longer," Budd explained.

It's currently spreading across the UK (Getty Stock Images)

The difference with flu, however, is that there is currently no vaccine for adenovirus.

Due to the cold, more people are getting ill because they're spending more time indoors and are in closer proximity to people who might be carrying a bug.

Budd explained: "With COVID-19 restrictions lifted and fewer people catching other viruses over the past few years, immunity in the community may be lower, leading to people becoming more susceptible.

"Adenovirus isn’t a new virus; it’s just showing up more often alongside other winter bugs."

Adenovirus symptoms

Public Health Scotland says the most common symptoms of an adenovirus include:

• common cold or flu-like symptoms (cough, runny nose, fever and/or chills)

• sore throat

• croup

• swollen glands

• acute bronchitis (inflammation of the airways of the lungs, sometimes called a 'chest cold')

• ear infection

• pneumonia (infection of the lungs)

• conjunctivitis (pink eye)

• acute gastroenteritis (inflammation of the stomach or intestines causing diarrhoea, vomiting, nausea and stomach pain)