The UK Health Security Agency (UKHSA) has issued a public alert about a common but highly contagious virus that many people may not recognise by name: adenovirus.
While most children contract it before the age of ten, the agency stresses that people of all ages can be infected at any time of year, and it can lead to more serious complications for some.
What is adenovirus and how does it spread?
In a recent post on X, formerly Twitter, and a detailed blog, the UKHSA explained that adenovirus is a common respiratory infection. It is often mild and mistaken for a common cold, but it can cause a range of other illnesses including conjunctivitis (pink eye), bronchitis, croup, ear infections, and gastroenteritis.
Unlike seasonal flu, adenovirus infections do not follow a seasonal pattern and can occur year-round. The virus is known for surviving on surfaces for extended periods, making shared objects potential sources of infection.
It spreads easily in places where people are in close contact, such as nurseries, schools, and hospitals. Transmission typically occurs through:
- Respiratory droplets from coughs or sneezes.
- Close personal contact like shaking hands.
- Touching contaminated surfaces then touching the face.
- Contact with an infected person's faeces, for example during nappy changing.
- Contaminated water in swimming pools (less common).
Key symptoms and when to seek help
Symptoms usually appear between two days and two weeks after exposure. According to the UKHSA, the four key signs of an adenovirus infection are:
- Fever
- Sore throat
- Runny or congested nose
- Cough
For most healthy individuals, the infection clears up on its own with rest and fluids, lasting from a few days to a couple of weeks. However, people can continue to shed the virus after recovery, sometimes without symptoms, potentially passing it to others.
The agency advises that medical advice should be sought if symptoms are severe or if the person is vulnerable. Contact a doctor if you or your child experiences:
- A high fever or one lasting more than a few days.
- Difficulty breathing.
- Red eyes, eye pain, or vision changes.
- Severe diarrhoea, vomiting, or signs of dehydration.
- If the infected person is under three months old or has a weakened immune system.
Who is most at risk?
While usually mild, adenovirus can be more serious for specific groups. People with weakened immune systems, the very young, and the elderly are at greater risk of severe illness and may require hospital treatment in some cases, particularly for complications like dehydration from vomiting and diarrhoea.
The UKHSA's key message is one of awareness: "While adenovirus infections are common and usually mild, knowing what to look out for can help you manage symptoms at home and recognise when professional advice is needed."
