It's flu season

It’s flu season, and after much delay, and coming and going, the flu vaccines are finally available. What is flu? How can you prevent catching it? And should you be immunised?

Winter sees a peak in all respiratory illnesses, from common colds, sinusitis, tonsillitis, and laryngitis to more significant illnesses including influenza (flu) and pneumonia. Three main types of influenza virus cause illness in humans - A , B and C and various subtypes. The influenza virus undergoes changes producing new strains so immunity to next years strains can never be obtained. The peak incidence for flu in Australia is from May to September, in the northern hemisphere it is from December to March.

Influenza is contagious and can be passed from droplets that are sneezed or coughed, or transferred by hand from objects the droplets or mucous land on, then directly to the nose or eyes.  Adults with flu are generally contagious for 3-5 days and children for up to 7-10 days, and the tiredness and unwell feeling can last for 1-2 weeks.

Influenza can range from a mild to a severe illness, but people affected will typically experience a rapid onset of some or all of the following:

• Dry cough 
• Fever or chills
• Muscle aches, joint pain, fatigue, headaches
• and sometimes nausea, vomiting or diarrhoea.

Influenza can also be complicated by e.g. pneumonia, requiring hospital admission.  While anyone can catch flu, certain groups are at higher risk of complicated flu - those with pre-existing medical conditions, pregnant women, the elderly (>65years) and the very young.  Outbreaks are more likely in closed environments like residential homes, schools, prisons and cruise ships.

Antiviral medication can prevent these complications,  and is recommended for at-risk people who can start treatment within 48 hours of the onset of symptoms. Treatment is not usually prescribed for people who are normally fit and healthy, but for all people affected, medical attention should be sought urgently in the case of shortness of breath, chest pain or coughing up blood.

The flu vaccine is the best prevention against outbreaks of influenza.  Vaccination is recommended to all at-risk groups, those in closed environments (see above), health care workers and those travelling overseas. The vaccines are updated each year to reflect the changes that occur in the virus and typically cover three strains (trivalent). A quadrivalent vaccine will be available privately for the first time this year, and includes a 4th B strain which may offer slightly higher protection.  However it is not widely available yet. 

The flu vaccine is provided free of charge if you are in an at-risk group, or available through your GP privately. Many employers also provide it for free or recommend it to their staff. The majority of flu vaccines can be given to those with egg allergy. If you need a flu shot this year make an appointment soon before the season is fully upon us.

In the meantime keep yourself as healthy as you can by following preventative measures and if you do become unwell stay at home, rest, take painkillers, drink plenty and do your best to prevent spreading it to others.