A respiratory illness described as a “mystery virus” spreading across the UK this winter has been identified as adenovirus, a common group of viruses that typically cause mild illness.
Reports of sore throats, coughs, and flu like symptoms have prompted public concern. But health experts and pharmacists say adenovirus is not new and is circulating at expected seasonal levels alongside other winter viruses.
Surveillance data from UK Health Security Agency shows adenovirus positivity fluctuating within baseline ranges, recently between 1.2% and 1.7% of laboratory tests. Higher rates are seen among young children.
What adenovirus is and why it is circulating now
Adenovirus is a widespread family of viruses that can infect people of all ages. It is especially common in children and usually causes mild illness. There are many strains, some affecting the respiratory tract, others the eyes or the gut.
Respiratory viruses tend to spread more easily during winter and early spring when people spend more time indoors. With Covid restrictions lifted and reduced exposure to common viruses in recent years, some degree of lowered community immunity may be contributing to increased susceptibility. Experts stress this does not mean adenovirus is new or unusually dangerous.
Symptoms people are reporting
Adenovirus infections often resemble a cold or flu. Reported symptoms include:
- Sore throat
- Runny or blocked nose
- Cough
- Fever
- Fatigue
- Headache or body aches
- Shortness of breath in fewer cases
Some strains can also cause conjunctivitis, leading to red, watery, or gritty eyes. Ear infections are more common in children, and certain types may trigger gastrointestinal symptoms such as nausea, vomiting, or diarrhoea.
How adenovirus compares with colds and flu
Compared with the common cold, adenovirus is more likely to cause fever and eye infections, and symptoms can last longer. Unlike flu, body aches and fatigue are usually less severe. There is no specific vaccine available for adenovirus in the general population.
| Symptom | Common cold | Flu | Adenovirus |
|---|---|---|---|
| Fever | Sometimes | Often | Often |
| Sore throat | Yes | Yes | Yes |
| Body aches and fatigue | Mild | Prominent | Variable |
| Pink eye | Rare | Very rare | More common |
| Gastro symptoms | Rare | Rare | Can occur |
| Seasonal pattern | Autumn and winter | Winter | Year round, more common in winter |
| Specific vaccine | No | Yes | No |
Preventing spread and managing infection
Good hygiene remains the most effective way to reduce transmission. This includes regular handwashing, covering coughs and sneezes, cleaning frequently touched surfaces, and staying at home when unwell. Mask wearing may be considered in crowded or high risk settings.
There is no specific antiviral treatment for adenovirus. Care focuses on rest, fluids, and symptom relief such as paracetamol or ibuprofen. Antibiotics do not work against viral infections. Medical advice should be sought if symptoms worsen, persist, or affect people at higher risk, including young children, older adults, and those who are immunocompromised.
Ian Budd, lead prescribing pharmacist at Chemist4U, said: “Adenovirus is not a new threat, but with more respiratory viruses circulating, it’s showing up more often. Most people will get better with simple at-home care, but good hygiene and staying home when unwell will help protect everyone around you.”
Public health bodies continue to monitor adenovirus activity and say current levels remain consistent with expected seasonal patterns.
