Influenza or the seasonal flu is a highly infectious acute viral infection caused by the influenza virus. It affects mainly the nose, throat, bronchial tubes, and occasionally the lungs. The symptoms may last from a few days to a week and a person generally improves without any active treatment. It can become extremely severe and may even be life-threatening, especially in people at risk such as the elderly, very young children, or those with certain medical conditions like HIV/AIDS.
Causes of Influenza
Influenza can be caused by any of the three types of viruses – A, B and C. Type A and type B influenza viruses are generally involved with causing epidemics, while type C causes a milder form of the illness which does not lead to epidemics of influenza. Type A virus is more likely to mutate to a different strain, to which people have no resistance. In 2009, a new strain of influenza virus spread worldwide, causing a pandemic. It was named H1N1 influenza or swine flu.
When an infected person coughs or sneezes, tiny droplets carrying the virus are expelled from the nose or mouth and can be inhaled by others in close contact. These droplets can remain suspended in the air or may be deposited on nearby surfaces, from where they are spread to others touching these surfaces and then bringing the contaminated hand near the mouth or nose. Direct contact, such as shaking hands, can also spread the disease.
Symptoms of Influenza
The symptoms of influenza are often quite similar to those of the common cold, but flu symptoms generally come on very suddenly and they are usually of a more severe nature.
Seasonal flu can give rise to any of these symptoms :
- Sudden fever, usually over 38 degrees celsius in adults. Children may have even higher temperatures.
- Dry cough.
- Runny or stuffy nose.
- Sore throat.
- Chills and sweating.
- Muscle pain.
- Body aches.
- Loss of appetite.
- Nausea, vomiting or diarrhoea is more common in children.
The symptoms are most severe within the first 2 or 3 days and then gradually improves. People suffering from seasonal flu normally recover in about a week’s time. However, a chest infection or other complications may develop in susceptible people, sometimes leading to death if adequate treatment is not implemented.
Treatment of Influenza
In most people, no active treatment is necessary and management can be done at home. Bed rest and plenty of fluids by mouth may be all that is needed. In certain cases, antiviral drugs may be prescribed, such as oseltamivir or zanamivir. Antivirals may help to shorten the duration of illness, reduce the severity of symptoms or prevent complications.
Pain relievers such as acetaminophen or ibuprofen may be used if necessary. Aspirin should never be given to children below the age of 16 because of the risk of Reye’s syndrome, a potentially fatal disease. Paracetamol is always a safer option. Antibiotics have no role in treatment of a viral infection but may be given if there is associated chest infection or pneumonia.
Preventing the Flu
Preventing the flu is all about keeping healthy. While you may not be able to avoid the flu entirely, a healthy body will ensure that you can overcome the infection as soon as possible. This involves :
- healthy eating
- avoiding excessive intake of alcohol and cigarette smoking
- stress management
The flu vaccine is a popular option for preventing the infection. Annual vaccinations against seasonal flu can help to prevent the disease in most cases but with the rapidly mutating virus, it is still possible to get the flu although the symptoms will usually be milder. The influenza vaccine but does not protect you against the swine flu. Combination vaccines may be available where you get protection for both influenza and swine flu. If not, you will have to take the swine flu vaccine separately.