What are colds and flu?

Nobody escapes the common cold – the average adult in the UK catches between two and four colds every year ⁽¹⁾. Flu – short for influenza – is also common, but it’s more severe, and can be life-threatening for older people and those with weakened immune systems.

Viruses cause colds and flu, but because we are exposed to them all our lives, our bodies build up immunity so that we can fight them and recover.

The viruses grow in the nose, throat, sinuses, airways and lungs. The body attacks them by becoming inflamed, developing mucus and running a fever, all of which can be very uncomfortable.

The cold is the commonest upper respiratory illness in the UK and can be caused by more than 100 different viruses ⁽²⁾, which explain why it’s common to catch one cold after another.

Flu is more severe – it’s a disease of the upper respiratory tract. There are three main strains of flu virus ⁽³⁾ which can sweep the community: A, B and C.

Babies and infants catch more colds than adults – as many as 12 a year are normal – because they haven’t built up immunity. Each year in the UK about 20 per cent of adults catch flu (and five per cent of children), but only one per cent of adults need hospital treatment for it ⁽⁴⁾.

How do you catch them?

Cold and flu viruses are highly contagious. They are spread by droplets of infected saliva in the air, so we easily catch colds or flu by breathing in others’ infected breath or sneezes, or by touching something infected and then touching our eyes, nose or mouth.

Once infected, a person can spread the illness even before their own symptoms appear (which can take up to four days) and for up to five days after symptoms have gone away. In the case of children or people with damaged immune systems, the infectious period lasts for longer ⁽⁴⁾.

What are the symptoms?

Cold symptoms can last anywhere from two to 14 days ⁽⁴⁾ and include:

• Sore throat
• Cough
• Blocked or runny nose with first clear and then yellow-green mucus
• Mild fever
• Headache
• Mild earache
• Congested heavy-headed feeling
• Tiredness
• Muscle aches

Flu symptoms are similar to those for a cold, but more severe:

• High fever (over 100˚F/ 38˚C)
• Harsh dry cough
• Occasional nausea or vomiting
• Diarrhoea
• Headaches, fatigue and muscle aches
• Problems sleeping and loss of appetite

Many people confuse a heavy cold with flu, but with flu there isn’t usually the heavy-headed feeling of a cold and the problem is more in the lungs.

Flu symptoms also come on more quickly than a cold, with severe symptoms, such as fever for three-five days. Usually people are feeling a lot better by the eighth day but it can take as many as three weeks before all the tiredness and coughing goes away.

Babies and young children with flu may have convulsions due to fever, be drowsy or lethargic ⁽⁵⁾.

The dangers of flu

The common cold is harmless to most healthy people and will clear up without medical help.

Some people can have bacterial complications, such as chest infections, which may need antibiotic treatment, as well as an infection of the sinuses, called bacterial sinusitis.

Flu is also common and a healthy person will recover without medical assistance. But flu carries a higher risk of serious bacterial complications, including anything from chest infections to encephalitis ⁽⁶⁾.

The danger of flu arises when severe complications occur in vulnerable people – the young, the old and people already ill – who may not be able to fight off these further conditions.

In the UK, around 13 million people are at increased risk of complications from flu, such as bronchitis and pneumonia. Mortality rates in the winter months are closely correlated with the pattern of influenza activity and result in an estimated average of 12,000 deaths annually.

Flu vaccination

If you match any of the criteria below, you will be eligible to receive a free flu vaccination and should obtain one from your local GP surgery or medical centre before the start of the flu season (December to March).

At-risk groups eligible for flu vaccination:

• People aged 65 years and over
• People with an weakened immune system (immunosuppression)
• People with diabetes
• People with asthma or chronic obstructive pulmonary disease (COPD)
• People with kidney disease/failure
• People with coronary heart disease
• Chronic neurological disease, such as Alzheimer’s or Parkinson’s
• Elderly people living in a care home (infections spread more easily)

Do I need to see a doctor?

If you’re an adult under 65 and in good health, the cold or flu is unlikely to develop complications and should clear up with home care – there’s no need to see your GP.

But if you are over 65, have a long-term illness, have been suffering from a chest condition before you got the cold/flu, are caring for a child or frail person, or notice any of the following signs of complications, see your GP:

• Cough lasting more than three weeks
• Chest pains
• Shortness of breath
• Severe symptoms lasting more than a week
• Very severe symptoms

Treatment

There is no medicine that can cure cold or flu. This is because the infections are caused by a virus, not bacteria, so antibiotics cannot help.

Usually a GP will only prescribe antibiotics if the cold or flu has led to a bacterial infection of the chest, for example.

The best way to treat cold or flu is:

• Stay in bed and rest while the illness is at its worst, usually for around two or three days after it has peaked. Stay warm, but a little fresh air is advised
• Drink water, fruit juice and soup for hydration. Avoid alcohol
• Over-the-counter remedies, such as decongestants, throat lozenges and steam inhalation may help. Painkillers, such as paracetamol, will bring down fever. In all cases follow the advice on the packet, or ask your pharmacist for advice
• Don't smoke and avoid smoky environments
• Eat plenty of fruits and vegetables that contain vitamins and minerals which fortify the body

Antiviral medication

If there is a flu epidemic and your doctor thinks you may be at risk from complications, you might be prescribed antiviral medicines. They can’t stop the flu, but can help lessen its duration and severity ⁽⁷⁾.

As of August 2008, the National Institute of Health and Clinical Excellence (NICE) recommend treatment with Tamilflu ® (oseltamivir) and Relenza ® (zanamivir) for the post-exposure treatment of influenza under the following circumstances:

• National surveillance schemes have indicated that influenza virus is circulating
• The person is in an at-risk group (see above list)
• The person has been exposed to an influenza-like illness and is able to begin prophylaxis within 36 hours of contact for zanamivir and within 48 hours of contact for oseltamivir
• The person has not been effectively protected by vaccination

How to prevent cold and flu

There is no guarantee you won’t catch a cold or flu, but the following precautions may reduce spreading the infection:

• Get vaccinated: UK studies show that the free flu vaccine reduces complications, cuts hospital admissions by up to 60 per cent and mortality by about 40 per cent. The vaccine is available at your GP's surgery every October/ early November for everyone over 65, and others at risk (see above list)
• Wash your hands: regularly to stop the spread of droplets, cover your mouth when coughing or sneezing, don’t share mugs and cutlery with others, and destroy used tissues straight away
• Avoid people already ill with colds or flu, or visit with other people if you are ill
• Eat a balanced diet with plenty of fresh fruit and vegetables, getting exercise, and not smoking all keep the body’s immune system strong

Pandemic Flu

The flu virus can, on rare occasions, mutate and a new strain of virus emerges. Such an event can cause many millions of deaths. The last time a flu pandemic occurred was in 1918, with the Spanish Flu outbreak. The number estimated to have died in the outbreak was estimated at between 50 and 100 million people worldwide ⁽⁸⁾.

As a result, the World Health Organization is keeping a close eye on Bird Flu (Avian Flu). The current H5N1 strain is a fast-mutating, deadly avian influenza virus found in multiple bird species.

Currently, the virus can only spread between birds, but can affect humans who come into close contact with infected animals. Avian Flu has been documented in 200 laboratory confirmed cases with 110 of these as fatalities. Cases of Avian Flu in humans have been documented in Laos, Vietnam, Romania, China, Turkey and Russia ⁽⁹⁾.

Scientists are worried that if the H5N1 virus mutates, it could then be able to pass from human to human. If this form of transmission occurs, another big pandemic could result in many deaths.

However, disease-control centres around the world are making Avian Flu their top priority and are stockpiling antiviral drugs.

Infolinks:

Common Cold Centre

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