Adenovirus vs. Flu: How to Tell the Difference This Season

As the UK endures a cold, prolonged winter, respiratory illnesses are tightening their grip once again.

While influenza remains a familiar seasonal threat, adenovirus has emerged as a quieter but highly contagious concern. Both can begin with coughs, fever and fatigue, making them difficult to tell apart in the early days.

But understanding how adenovirus differs from flu can help manage expectations, reduce unnecessary antibiotic use and clarify when medical help is needed.

With the NHS already under pressure, knowing the signs has never mattered more.

What Is Adenovirus?

Adenovirus is a DNA virus that can infect various tissues, including the respiratory, ocular, and gastrointestinal systems. Dr Deborah Lee of Dr Fox Online Pharmacy states that the majority of adenovirus infections are mild. Yet, they can be deadly or cause severe outcomes in immunosuppressed patients, as can other diseases.

Adenovirus does not occur only during winter, as with the flu. It can spread year-round and is therefore a perennial problem in schools, care facilities, and crowded places. As the Independent explains, adenovirus is more resistant to time on the surface and to disinfectants, and is therefore more likely to be transmitted, due to its high contagiousness.

Symptoms: Detection of Signs

Adenovirus and the flu share overlapping symptoms, including fever, cough, sore throat, and fatigue. Nonetheless, there are some minor differences:

Common symptoms of adenovirus are conjunctivitis (eye infection), diarrhoea, vomiting, and tummy pain, as well as respiratory complications. These may take up to two weeks, and the cough may take longer.

The symptoms of the flu tend to come on quickly and are characterised by a high fever, chills, muscle aches, and intense muscle fatigue. Flu tends to have a more dramatic onset than adenovirus, which causes cold-like symptoms.

According to The Independent, adenovirus may cause stomach flu and vomiting in severe cases, emphasising that it can affect the respiratory system as well as the stomach.

How Contagious Are They?

Both viruses are readily transmitted, but the adenovirus is particularly resistant. Airborne droplets, close contact, or contaminated surfaces may spread it. Worryingly, even after the symptoms have gone, people can still be contagious.

Flu, on the other hand, is transmitted mainly through respiratory droplets and usually peaks in winter. There is no approved vaccine for adenovirus; annual flu vaccination programmes aim to reduce severity and transmission.

Prevention and Protection

Preventing adenovirus requires more than conventional hygiene. According to experts, washing hands carefully, not touching the face, and cleaning surfaces with bleach or hydrogen peroxide are recommended, as the adenovirus is not affected by soap or most household cleaning agents.

In the case of the flu, the best line of defence is to vaccinate and practice respiratory hygiene, including covering coughs and sneezes. Both diseases emphasise the importance of ventilation in the indoor environment and the inadvisability of close contact with symptomatic individuals.

Treatment Approaches

There is no cure for the adenovirus. The majority of adenoviruses are self-limiting, and treatment is primarily aimed at managing symptoms: paracetamol or ibuprofen for fever, saltwater gargles for sore throats, and rest. Viruses are resistant to antibiotics.

For flu management, antiviral drugs can be prescribed to shorten illness duration or prevent complications, especially for vulnerable populations. The two diseases may pose a threat to infants, people who are aged, pregnant women, and those with compromised immunity.

Why It Matters This Season

Adenovirus is emerging as a new complication for the NHS, which is already under strain due to the flu and winter pressures. This is because it is difficult to trace and control, given its ability to simulate flu symptoms and its year-round activity. Adenovirus's persistence on surfaces allows it to remain active longer and makes it resistant to most disinfectants, as The Independent warns.

Flu will attack with sudden, severe effects, whereas adenovirus will cause milder, more widespread effects. They are both highly contagious, yet adenovirus is quite difficult to contain by nature due to its resilience. This is the season of vigilance, hygiene, and awareness, which can help one stay healthy.