Flu Facts From PPP Healthcare

What is it?

Influenza (or flu) is a short lived illness caused by a virus infection. There are different forms of the influenza virus, namely types A and B. Each type has a different structure and is responsible for different patterns of the illness seen in the community. 

Type A: This was discovered in 1933 and has been responsible for world wide outbreaks of the disease in each country such as those in 1957 (known as Asian flu), in 1968 (Hong Kong flu) and in 1977 (Red flu). 

Type B: This causes less extensive outbreaks, especially seen in institutions such as boarding schools and army camps. 

Each type of virus can be further classified into smaller groups, or strains, according to certain biological properties or characters situated on the surface of the virus. The significance of these strains lies in their ability to undergo a major change in character (mutant strains) and thereby allow the spread of new forms in the community which are the basis of the epidemics that have occured in the past. 

Influenza is an infectious disease and is spread by the so called droplet method ie, through mucus which is spread through coughing and sneezing. 

What are the symptoms?

Influenza can affect people at any age and symptoms usually come on quite abruptly. The commonest symptoms are a sudden fever, chills, headache and aching in the limbs. Almost everybody gets a dry cough and often a sore throat. Commonly patients feel quite weak following recovery from the acute illness and sometimes mild depression can occur. Fortunately these symptoms settle within a few weeks. 

Influenza is a well defined clinical illness which is often confused with the common cold. It is distinguised from this and other upper respiratory tract infections by the aches, weakness and lethargy which characterise the illness. 

What is the treatment?

Following an attack, simple measures should be sufficient to treat influenza. This means resting in bed and drinking plenty of fluids. Analgesic remedies containing aspirin and paracetamol are useful and can be obtained over the counter from the local pharmacist without a prescription. These should help bring down the temperature and relieve the pain. 

For the normally healthy person, recovery will occur within a few days and there may well be no need to contact the family doctor at all. A return to full fitness may take longer in those who feel weak, and so rehabiliation then must be a gradual process. If, however, there are other known health problems such as previous chest or heart problems then it may be necessary to seek medical advice in order to avoid or minimise complications. 

What are the complications?

Complications from influenza occur mostly in the elderly and fall into two main groups as outlined below: 

Respiratory: This may take the form of a true influenza virus lung infection which is rare. More commonly a bacterial chest infection occurs, which is treatable with antibiotics. 

Other complications: Rarely influenza can affect the heart causing inflammation (myocarditis and pericarditis) or the nervous system causing inflammation of the brain (encephalitis) and referral to hospital may be necessary. 

How can it be prevented?

Protection against influenza can be achieved by immunisation, and in the UK the aim is protect those at increased risk of developing complications should they develop influenza. The vaccine is manufactured from an influenza virus which has been 'inactivated' (ie rendered harmless) and grown on hens eggs. 

Each year the vaccine contains the virus strains (usually comprising two type A strains and one type B) that are most likely to be circulating in the UK in the forthcoming winter. These are predicted by constant monitoring of these viruses in laboratories throughout the world. The vaccine is then commercially available via the pharmaceutical industry to health authorities and family doctors for administration to patients. 

Who should be vaccinated?

The Department of Health recommends influenza vaccination for certain people who fall into any of the following at risk categories:

• Chronic respiratory disease including asthma, chronic bronchitis, and emphysema
• Chronic heart disease, of whatever type
• Chronic kidney failure
• Diabetes
• Cancer patients taking long term anti cancer drugs which suppress the body's immune system and patients on long term steroids
• Residents of old peoples homes, nursing homes and other long stay establishments where rapid spread of infection is a possibility

 
Vaccination is not routinely recommended for any outside these groups. The merits of vaccination can be discussed the family doctor. Vaccination is 60 effective in preventing infection in healthy adults but only as half as effective in the elderly. The vaccination may reduce the incidence of hospital admisssions for elderly people suffering from pneumonia. Mortality amongst the elderly from influenza can by reduced by 40% through vaccination.