Then there’s the flu …

Flu, or influenza, is a common viral respiratory illness that can be life-threatening, especially in the elderly and frail. There have been many well-documented influenza epidemics throughout history. The most severe outbreak of modern times was the 1918 epidemic which claimed more than 20 million lives.

Fresh outbreaks occur because the flu virus can slightly change its structure which removes any immunity people may have previously acquired. Nowadays, an international surveillance system is in place to detect these changes in the virus. A new vaccine is produced each year to cover the types of influenza that are most likely to be encountered.

Around Australia there are several specialised viral laboratories and sentinel medical practices. When the first flu-like illnesses appear, swabs are taken and viral cultures performed to rapidly identify the virus or viruses responsible. Patients admitted to hospital with suspected flu are also tested. A pattern quickly develops and the flu is carefully charted Australia-wide over subsequent weeks.

The symptoms of flu can be dramatic. The patient usually develops a high fever and severe aches and pains. Headaches, sore throat and a cough frequently occur, and the person is often barely able to move from their bed.

Medical experts say immunising high-risk individuals with the flu-vaccine is the best way to combat influenza. Those particularly at risk are:

• People over 65 years of age.
• All residents of nursing homes and other chronic care facilities.
• Adults and children with chronic diseases like heart, lung and kidney problems.
• People whose immune system is suppressed or those on treatments like chemotherapy.

People in these categories should be immunised each year, preferably in early autumn. Unfortunately, fewer than half high-risk Australians have been receiving the flu vaccine, even though it is at least 70 per cent effective.

Some people falsely believe they might catch the flu from a flu vaccine. This is impossible because it is an inactive vaccine that does not contain any live virus. However, in children or those previously never exposed to the flu, a slight fever may occur for a day or two after the immunisation. Because the flu vaccine is prepared from eggs, people who are highly allergic to eggs should not be given the vaccine.